45,774 research outputs found

    The primacy of microchips in the security design of embedded devices

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    The global embedded system market is projected to grow from 86.5Billionin2020to86.5 Billion in 2020 to 116.2 Billion by 2025. The increased prevalence of embedded devices and the boost in sophisticated attacks against them has made embedded system security an intricate and pressing issue. Embedded systems are at the center of many different electronic products, machines, and intelligent operations, despite being designed to focus on specific tasks and completing those tasks perfectly, they often pose security and privacy issues. For example, embedded systems such as widely deployed medical devices, are posing a pressing issue due to their inadequate security design. These devices once compromised, can lead to death and injury of patients in clinical environments. Another example is the Unmanned Aerial Vehicles (UAVs), also known as “drones”,with the promise of enabling many favorable applications. Besides military purpose, many industries are paying more attention to the commercial usage of drones. For example, Amazon announced its Air PrimeDelivery Service in 2013, aiming to deploy small drones to deliver lightweight packages. However, the further adoption of drones has been significantly impeded by an overwhelming public outcry over the security and privacy implications of drone technology. Additionally, Amazon’s Alexa and similar voice assistant devices are capable of recording every conversation. This appears to be by design in order to allow the device to be responsive to “wake up” commands such as “Hey Alexa!”. However, such capability without properly securing the collected data causes many security and privacy complications. The economic and mortality impacts of the vulnerabilities in devices as described above have been widely discussed, but there is limited in quest that has focused on identifying the root causes of these issues. In this dissertation, I have identified several critical issues that have roots in the security design of embedded devices. As an example, I have demonstrated that widely used Medical Infusion Pumps could easily be compromised since developers/manufacturers have utilized insecure username and password such as“admin” and “12345” as the main method of authentication on their product. To make things worse, they have also decided to transmit variety of sensitive data in plain text instead of utilizing modern encryption methods for data in transit. In another example, I have demonstrated how an additive manufacturing equipment such as a 3D printer and the designs residing on the printer can be easily compromised due to the lack of proper authentication and data security. While conducting these studies, it emerged that the underutilization of security protocols existing on microcontrollers within each embedded device is the root cause of many vulnerabilities. At this step, the question of “Why more capable security protocols despite being available on the microcontrollers aren’t being used?” replaced the “Why this device is vulnerable?”. It is evident that from the manufacturer’s perspective, the time to market of a product is crucial. To make things worse, often developers will sacrifice spending more time and paying attention to security components in favor of a faster release cycle. I have identified that the main issue descents during the design phase of such devices. Developers are frequently rushed to develop the main functionality of these devices and omit to forget the “Security by Design” principal. As a result, vast majority of embedded devices are being released to the public without implementing modern security protocols despite being supported by the underlining hardware.I have researched, designed, and developed an intuitive web-based tool capable of efficiently and effectively guiding developers and manufactures to identify the supported security protocols of hundreds of microcontrollers. I focus on multiple methods to collect, parse, analyze, and identify the available security protocols of hundreds of microcontrollers that are often time-consuming to identify and challenging to categorize for developers. The current process results in frustration and ultimately unawareness of many essential capabilities of microcontrollers such as elevated security protocols. The developed solution will determinately enable developers to save time, reduce error, fully utilize the hardware’s capability at their disposal, and ultimately increase the security posture of their final product. My approach revealed that, a web-based tool designed to return the supported cryptographic protocols based on the inputted microcontroller model with a simple and intuitive interface can facilitate the design phase of an embedded device without sacrificing security. I experimentally validate the correctness of the developed framework by obtaining a patient monitor, a form of medical device and reverse engineering it to 1. validating the presence or absence of secure authentication and encryption of data in transit 2. validating that the underlining hardware supports modern security protocols via utilizing the developed framework, and 3. concluding that despite the availability of a stronger security protocol, developers/manufactures have neglected to utilize these protocols.LimitedAuthor requested closed access (OA after 2yrs) in Vireo ETD syste

    Key technologies for safe and autonomous drones

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    Drones/UAVs are able to perform air operations that are very difficult to be performed by manned aircrafts. In addition, drones' usage brings significant economic savings and environmental benefits, while reducing risks to human life. In this paper, we present key technologies that enable development of drone systems. The technologies are identified based on the usages of drones (driven by COMP4DRONES project use cases). These technologies are grouped into four categories: U-space capabilities, system functions, payloads, and tools. Also, we present the contributions of the COMP4DRONES project to improve existing technologies. These contributions aim to ease drones’ customization, and enable their safe operation.This project has received funding from the ECSEL Joint Undertaking (JU) under grant agreement No 826610. The JU receives support from the European Union’s Horizon 2020 research and innovation programme and Spain, Austria, Belgium, Czech Republic, France, Italy, Latvia, Netherlands. The total project budget is 28,590,748.75 EUR (excluding ESIF partners), while the requested grant is 7,983,731.61 EUR to ECSEL JU, and 8,874,523.84 EUR of National and ESIF Funding. The project has been started on 1st October 2019

    Meso-scale FDM material layout design strategies under manufacturability constraints and fracture conditions

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    In the manufacturability-driven design (MDD) perspective, manufacturability of the product or system is the most important of the design requirements. In addition to being able to ensure that complex designs (e.g., topology optimization) are manufacturable with a given process or process family, MDD also helps mechanical designers to take advantage of unique process-material effects generated during manufacturing. One of the most recognizable examples of this comes from the scanning-type family of additive manufacturing (AM) processes; the most notable and familiar member of this family is the fused deposition modeling (FDM) or fused filament fabrication (FFF) process. This process works by selectively depositing uniform, approximately isotropic beads or elements of molten thermoplastic material (typically structural engineering plastics) in a series of pre-specified traces to build each layer of the part. There are many interesting 2-D and 3-D mechanical design problems that can be explored by designing the layout of these elements. The resulting structured, hierarchical material (which is both manufacturable and customized layer-by-layer within the limits of the process and material) can be defined as a manufacturing process-driven structured material (MPDSM). This dissertation explores several practical methods for designing these element layouts for 2-D and 3-D meso-scale mechanical problems, focusing ultimately on design-for-fracture. Three different fracture conditions are explored: (1) cases where a crack must be prevented or stopped, (2) cases where the crack must be encouraged or accelerated, and (3) cases where cracks must grow in a simple pre-determined pattern. Several new design tools, including a mapping method for the FDM manufacturability constraints, three major literature reviews, the collection, organization, and analysis of several large (qualitative and quantitative) multi-scale datasets on the fracture behavior of FDM-processed materials, some new experimental equipment, and the refinement of a fast and simple g-code generator based on commercially-available software, were developed and refined to support the design of MPDSMs under fracture conditions. The refined design method and rules were experimentally validated using a series of case studies (involving both design and physical testing of the designs) at the end of the dissertation. Finally, a simple design guide for practicing engineers who are not experts in advanced solid mechanics nor process-tailored materials was developed from the results of this project.U of I OnlyAuthor's request

    Compósitos de cortiça: uma solução sustentável em moldação por injeção e manufatura aditiva

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    Today, the world that we live in is moving fast towards the Digital, which is causing profound technological mutations. Additive Manufacturing (AM), commonly called “3D printing”, is one of the symbols of these digital and technological effervescence. Initially, AM technologies were only seen as rapid prototyping tools. Nowadays, this stigma has changed and the market began to look at AM technologies as an effective and competitive alternative to the manufacture of products besides the conventional techniques. Cork is the world’s ambassador Portuguese material! A 100% natural material and it presents a unique combination of properties, given its composition and alveolar structure. Low density, hydrophobic character, elasticity and impact resistance are some its properties. This feature makes cork a material high potential in several applications. Wine stoppers is the major application of cork. From this production is generated a large amount of cork residues with different granulometries, where residues with calibres superior than 0.5-1.0 mm are already used in the development of cork-based composites for flooring and insulation applications. The valorisation of these cork residues through the development of new sustainable composite materials was one of the main motivations that triggered the present work. This thesis reports the development of cork-polymer composites (CPC) and cork-based formulations adapted to conventional and AM technologies. It will involve a conventional technology, the injection moulding (IM) technique, and two AM technologies, namely Fused Filament Fabrication (FFF) and 3D Printing (3DP). The preservation of cork alveolar structure after processing by these technologies was always sought. The present thesis is composed by a set of published papers in scientific journals and in conferences. Papers are integrated into two chapters (Chapter II and Chapter III). At the beginning of each chapter, it is presented an introduction to the topic. Chapter II concerns the development of CPC solutions adapted for IM, while Chapter III focus on the development of CPC and cork-based formulations solutions adapted to FFF and 3DP, respectively. Chapter II presents the study of the rheological and the non-isothermal crystallization behaviours of CPC. These studies have shown that the addition of cork did not compromise the flowability of CPC and its processability by IM. In addition, cork powder surface acted as a nucleating agent during non-isothermal crystallization. The presence of a coupling agent based on maleic anhydride (MA) contributed to the development of CPC with enhanced flowability, crystallinity degree and interfacial adhesion between the polymeric matrix and cork particles. A case study related to the effect of the high pressures applied during a standard IM process on the integrity of cork alveoli was performed. The application of low pressures, the removal of holding and back pressures and the use of shut-off nozzles were analysed as an adapted IM solution. Cork alveoli were able to recover from the deformation caused by the IM process, especially when cork granules were near to matrix defects (voids). A promising result which indicates that after an IM process the cork particles can recover its initial shape and size. On the other hand, Chapter III reports (i) the development of a cork-like filament with an incorporation of cork powder equal to 15 % (w/w), which represents 55 % in volume and (ii) the development of cork-based formulations adapted to 3DP. Focusing on the FFF technology, a case study was conducted to evaluate the usefulness and printability of the developed CPC filament. The printed parts exhibited unique characteristics, such as a non-plastic and warm touch, a natural colour and the release of a pleasant odour during the printing process. A case study, based on the 3DP technology, was conducted to evaluate the printability of the developed cork-based formulations. Previously, the applicability of the Washburn Capillary Rise (WCR) method was studied to determine the wettability of cork powders by a commercial binder (≥ 95% (w/w) of water). Cork powders are slightly wetted by the commercial binder (contact angles of () ≈ 86 – 87º). 3DP cork parts with complex geometry were successfully printed. Parts exhibited lightweight and, warmness and softness to the touch. From the available knowledge, it is believed that this was the first time that cork powders were processed by 3DP. In addition, the autoclave technique was also studied and validated as a post-processing phase in the 3DP process. The main conclusions and perspectives of future work are presented in Chapter IV. The present thesis constitutes an original approach for the valorisation of cork powder residues. The combination of a natural and traditional product, such as cork, with high-tech technologies, can lead to the development of cork products never processed before, or to new applications of cork products never thought before.Hoje, vivemos num mundo que caminha rapidamente para o Digital, o que provoca profundas mutações tecnológicas. A Manufatura Aditiva (MA), comumente denominada de Impressão 3D (3DP) é um dos símbolos desta efervescência digital e tecnológica. Inicialmente, as tecnologias de MA eram vistas como ferramentas de prototipagem rápida. Atualmente, esse estigma foi alterado e o mercado começou a olhar para as tecnologias de MA como uma alterativa eficaz e competitiva no fabrico de produtos para além das tecnologias de fabrico convencionais. A cortiça é o embaixador português no mundo dos materiais! É um material 100% natural e apresenta uma combinação única de propriedades, dada a sua composição e estrutura celular. Baixa densidade, carácter hidrofóbico, elasticidade e resistência ao impacto são exemplo de algumas das suas propriedades. Esta combinação única torna a cortiça num material com um elevado potencial em diversas aplicações. A produção de rolhas é a principal aplicação da cortiça. Desta produção são gerados resíduos com diferentes granulometrias, onde os resíduos com calibres superiores a 0.5-1.0 mm são já aplicados no fabrico de compósitos, nomeadamente para aplicações de revestimento e isolamento. A valorização destes resíduos de cortiça através do desenvolvimento de novos materiais compósitos sustentáveis foi uma das principais motivações que desencadeou o presente trabalho. A presente tese reporta o desenvolvimento de compósitos poliméricos de cortiça (CPC) e de formulações à base de cortiça adaptadas a tecnologias convencionais e de MA. O estudo envolve uma tecnologia convencional, a moldação por injeção (MI), e duas tecnologias de MA, nomeadamente as tecnologias de Fabricação por Filamento Fundido (FFF) e de 3DP. Após o processamento por estas tecnologias, procurar-se-á manter intacta a estrutura alveolar da cortiça. A tese é composta por um conjunto de artigos publicados em revistas científicas e em conferências. Os artigos encontram-se integrados em dois capítulos (Capítulo II e III). No início de cada capítulo é apresentada uma introdução ao tópico em questão. O Capítulo II apresenta um estudo reológico e um estudo de cristalização não isotérmica de CPC. Estes estudos demonstraram que a adição de cortiça não comprometeu a fluidez do CPC e o seu processamento por MI. Além disso, a superfície das partículas do pó de cortiça atuaram como agentes nucleantes durante a cristalização não-isotérmica. A presença de um agente compatibilizante à base de anidrido maleico (AM) contribuiu para o desenvolvimento de CPC com maior fluidez, grau de cristalinidade e adesão interfacial entre a matriz polimérica e a cortiça. Um estudo de caso foi conduzido para avaliar o efeito das pressões elevadas aplicadas, durante o processo de MI, na integridade da estrutura alveolar da cortiça. O efeito da injeção a baixas pressões, a remoção da pressão de compactação e de contrapressão e o uso de bicos obturadores foram analisados como uma solução adaptada ao processo de MI. Nesta solução adaptada de MI, os alvéolos da cortiça foram capazes de recuperar da deformação, em especial quando estavam próximos de defeitos da matriz (vazios). Um resultado promissor, pois indica que as partículas de cortiça podem recuperar a sua estrutura e tamanho após um processo de MI. Por outro lado, o Capítulo III relata o (i) desenvolvimento de um filamento de cortiça com uma incorporação de pó de cortiça igual a 15 % (p/p), o que representa 55% em volume e (ii) o desenvolvimento de formulações à base de cortiça adaptadas ao processo de 3DP. Focando na tecnologia de FFF, foi realizado um caso de estudo para avaliar a usabilidade e a capacidade de impressão do filamento de CPC desenvolvido. As peças impressas por FFF exibiriam características únicas, nomeadamente um toque não plástico e quente, uma cor natural e a libertação de odor agradável durante a impressão. Foi efetuado, por 3DP, um estudo de caso para avaliar a capacidade de impressão das formulações desenvolvidas. Previamente, a aplicabilidade do método de Washburn foi estudada para avaliar a molhabilidade de pós de cortiça por um ligante comercial (água ≥ 95% (p/p). Os pós de cortiça são ligeiramente molhados pelo ligante comercial (ângulo de contacto () de ≈ 86 – 87º). Foram impressas peças com geometrias complexas por 3DP. As peças exibiram leveza e um toque quente e macio. Do conhecimento disponível julga-se ter sido esta a primeira vez que se processaram pós de cortiça por 3DP. Além disso, foi também estudada e validada a técnica de autoclave como fase de pós processamento no processo de 3DP. As principais conclusões e as perspetivas de trabalhos futuros estão descritas no Capítulo IV. A presente tese constitui uma abordagem original na valorização de resíduos de pó de cortiça. A combinação de um material natural e tradicional, como a cortiça, com tecnologias de ponta, irá contribuir para o desenvolvimento de produtos de cortiça nunca antes processados ou, até mesmo, para novas aplicações de produtos de cortiça nunca antes pensadas.Programa Doutoral em Ciência e Engenharia de Materiai

    The Metaverse: Survey, Trends, Novel Pipeline Ecosystem & Future Directions

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    The Metaverse offers a second world beyond reality, where boundaries are non-existent, and possibilities are endless through engagement and immersive experiences using the virtual reality (VR) technology. Many disciplines can benefit from the advancement of the Metaverse when accurately developed, including the fields of technology, gaming, education, art, and culture. Nevertheless, developing the Metaverse environment to its full potential is an ambiguous task that needs proper guidance and directions. Existing surveys on the Metaverse focus only on a specific aspect and discipline of the Metaverse and lack a holistic view of the entire process. To this end, a more holistic, multi-disciplinary, in-depth, and academic and industry-oriented review is required to provide a thorough study of the Metaverse development pipeline. To address these issues, we present in this survey a novel multi-layered pipeline ecosystem composed of (1) the Metaverse computing, networking, communications and hardware infrastructure, (2) environment digitization, and (3) user interactions. For every layer, we discuss the components that detail the steps of its development. Also, for each of these components, we examine the impact of a set of enabling technologies and empowering domains (e.g., Artificial Intelligence, Security & Privacy, Blockchain, Business, Ethics, and Social) on its advancement. In addition, we explain the importance of these technologies to support decentralization, interoperability, user experiences, interactions, and monetization. Our presented study highlights the existing challenges for each component, followed by research directions and potential solutions. To the best of our knowledge, this survey is the most comprehensive and allows users, scholars, and entrepreneurs to get an in-depth understanding of the Metaverse ecosystem to find their opportunities and potentials for contribution

    The Effect of Flagella Stiffness on the Locomotion of a Multi-Flagellated Robot at Low Reynolds Environment

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    Microorganisms such as algae and bacteria move in a viscous environment with extremely low Reynolds (ReRe), where the viscous drag dominates the inertial forces. They have adapted to this environment by developing specialized features such as whole-body deformations and flexible structures such as flagella (with various shapes, sizes, and numbers) that break the symmetry during the motion. In this study, we hypothesize that the changes in the flexibility of the flagella during a cycle of movement impact locomotion dynamics of flagellated locomotion. To test our hypothesis, we developed an autonomous, self-propelled robot with four flexible, multi-segmented flagella actuated together by a single DC motor. The stiffness of the flagella during the locomotion is controlled via a cable-driven mechanism attached to the center of the robot. Experimental assessments of the robot's swimming demonstrate that increasing the flexibility of the flagella during recovery stroke and reducing the flexibility during power stroke improves the swimming performance of the robot. Our results give insight into how these microorganisms manipulate their biological features to propel themselves in low viscous media and are of great interest to biomedical and research applications

    NF-Atlas: Multi-Volume Neural Feature Fields for Large Scale LiDAR Mapping

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    LiDAR Mapping has been a long-standing problem in robotics. Recent progress in neural implicit representation has brought new opportunities to robotic mapping. In this paper, we propose the multi-volume neural feature fields, called NF-Atlas, which bridge the neural feature volumes with pose graph optimization. By regarding the neural feature volume as pose graph nodes and the relative pose between volumes as pose graph edges, the entire neural feature field becomes both locally rigid and globally elastic. Locally, the neural feature volume employs a sparse feature Octree and a small MLP to encode the submap SDF with an option of semantics. Learning the map using this structure allows for end-to-end solving of maximum a posteriori (MAP) based probabilistic mapping. Globally, the map is built volume by volume independently, avoiding catastrophic forgetting when mapping incrementally. Furthermore, when a loop closure occurs, with the elastic pose graph based representation, only updating the origin of neural volumes is required without remapping. Finally, these functionalities of NF-Atlas are validated. Thanks to the sparsity and the optimization based formulation, NF-Atlas shows competitive performance in terms of accuracy, efficiency and memory usage on both simulation and real-world datasets

    CLIP-Guided Vision-Language Pre-training for Question Answering in 3D Scenes

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    Training models to apply linguistic knowledge and visual concepts from 2D images to 3D world understanding is a promising direction that researchers have only recently started to explore. In this work, we design a novel 3D pre-training Vision-Language method that helps a model learn semantically meaningful and transferable 3D scene point cloud representations. We inject the representational power of the popular CLIP model into our 3D encoder by aligning the encoded 3D scene features with the corresponding 2D image and text embeddings produced by CLIP. To assess our model's 3D world reasoning capability, we evaluate it on the downstream task of 3D Visual Question Answering. Experimental quantitative and qualitative results show that our pre-training method outperforms state-of-the-art works in this task and leads to an interpretable representation of 3D scene features.Comment: CVPRW 2023. Code will be made publicly available: https://github.com/AlexDelitzas/3D-VQ

    RAPID: Enabling Fast Online Policy Learning in Dynamic Public Cloud Environments

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    Resource sharing between multiple workloads has become a prominent practice among cloud service providers, motivated by demand for improved resource utilization and reduced cost of ownership. Effective resource sharing, however, remains an open challenge due to the adverse effects that resource contention can have on high-priority, user-facing workloads with strict Quality of Service (QoS) requirements. Although recent approaches have demonstrated promising results, those works remain largely impractical in public cloud environments since workloads are not known in advance and may only run for a brief period, thus prohibiting offline learning and significantly hindering online learning. In this paper, we propose RAPID, a novel framework for fast, fully-online resource allocation policy learning in highly dynamic operating environments. RAPID leverages lightweight QoS predictions, enabled by domain-knowledge-inspired techniques for sample efficiency and bias reduction, to decouple control from conventional feedback sources and guide policy learning at a rate orders of magnitude faster than prior work. Evaluation on a real-world server platform with representative cloud workloads confirms that RAPID can learn stable resource allocation policies in minutes, as compared with hours in prior state-of-the-art, while improving QoS by 9.0x and increasing best-effort workload performance by 19-43%
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