303,864 research outputs found

    Time-sensitive autonomous architectures

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    Autonomous and software-defined vehicles (ASDVs) feature highly complex systems, coupling safety-critical and non-critical components such as infotainment. These systems require the highest connectivity, both inside the vehicle and with the outside world. An effective solution for network communication lies in Time-Sensitive Networking (TSN) which enables high-bandwidth and low-latency communications in a mixed-criticality environment. In this work, we present Time-Sensitive Autonomous Architectures (TSAA) to enable TSN in ASDVs. The software architecture is based on a hypervisor providing strong isolation and virtual access to TSN for virtual machines (VMs). TSAA latest iteration includes an autonomous car controlled by two Xilinx accelerators and a multiport TSN switch. We discuss the engineering challenges and the performance evaluation of the project demonstrator. In addition, we propose a Proof-of-Concept design of virtualized TSN to enable multiple VMs executing on a single board taking advantage of the inherent guarantees offered by TSN

    Product Lifecycle Management - Application of Patterning Methods to Gas Turbine Blades and Creation of Learning Materials

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    To compete in the global marketplace, companies need to embrace virtual design and manufacturing methods. Product Lifecycle Management (PLM) embodies both the workflow processes and tools to bring forth products from conception to design to fabrication to service to decommissioning, and to eventual recycling. In response to the growing demand for engineers and technicians with these critical skills, colleges and universities should introduce these virtual tools through seminars, software workshops, and computer laboratory sessions. Some of the opportunities in the PLM Center at Clemson University include short courses on PLM practices, focused software training sessions, hands-on exploration activities, and research projects. The participants across campus include creative inquiry students, capstone design classes, graduate researchers, and community outreach for K-12 students. Through these interactions, participants will gain insight into the challenges and opportunities with virtual engineering processes and software. The recent worldwide pandemic has demonstrated the need for engineers skilled in virtual design methods to enable the digital design, manufacturing, and support processes to occur in, and remote of, the workplace. Computer-aided design (CAD) and computer-aided engineering (CAE) methods embody the software tools that bring forth products from conception to design. A variety of packages are available, which allow for the progress of a product to be tracked and detailed changes to be made along the way. One complex product currently designed using CAE software is a natural gas fired turbine for electrical power generation. In these thermo-dynamic rotational systems, blade cooling using internal forced airflow is vital to withstand the operating temperatures in the combustion chamber. Accordingly, ribbed surface disruptors, known as turbulators, are placed inside the turbine blades to promote air mixing to help remove heat from the hot surfaces. Three CAE patterning features will be examined to create these turbulators with evaluation metrics based on the execution speed, accessibility, accuracy, adaptability, and relevance. The numerical case study results revealed that the face pattern method was the most suitable option with productivity time improvements of 5% in comparison to the feature and geometry pattern approaches. The feature pattern method proved to be viable for smaller modeling changes which require significant detail. However, the geometry patterning method did not show any indications of being a usable option over the others in any scenario tested. To prepare the next generation of engineers for these PLM processes and software tools, a PEER & WISE workshop module has been created for students to engage with these virtual concepts. In these four-day, 90-minute sessions, middle school students will learn about engineering design processes, fundamental engineering and science concepts, and CAD software. They will create virtual mechanical components using CAD software, while hands-on tasks will enable the creation of mechanical assemblies using discrete components to demonstrate the functionality of gears and drivelines. To assess the student experience, a survey was created and submitted for IRB approval. The pandemic created a unique situation for these prepared sessions as students could not participate right away, however, they will be offered in the future

    Seamless Variability Management With the Virtual Platform

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    Customization is a general trend in software engineering, demanding systems that support variable stakeholder requirements. Two opposing strategies are commonly used to create variants: software clone & own and software configuration with an integrated platform. Organizations often start with the former, which is cheap, agile, and supports quick innovation, but does not scale. The latter scales by establishing an integrated platform that shares software assets between variants, but requires high up-front investments or risky migration processes. So, could we have a method that allows an easy transition or even combine the benefits of both strategies? We propose a method and tool that supports a truly incremental development of variant-rich systems, exploiting a spectrum between both opposing strategies. We design, formalize, and prototype the variability-management framework virtual platform. It bridges clone & own and platform-oriented development. Relying on programming-language-independent conceptual structures representing software assets, it offers operators for engineering and evolving a system, comprising: traditional, asset-oriented operators and novel, feature-oriented operators for incrementally adopting concepts of an integrated platform. The operators record meta-data that is exploited by other operators to support the transition. Among others, they eliminate expensive feature-location effort or the need to trace clones. Our evaluation simulates the evolution of a real-world, clone-based system, measuring its costs and benefits.Comment: 13 pages, 10 figures; accepted for publication at the 43rd International Conference on Software Engineering (ICSE 2021), main technical trac

    Generative Invertible Networks (GIN): Pathophysiology-Interpretable Feature Mapping and Virtual Patient Generation

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    Machine learning methods play increasingly important roles in pre-procedural planning for complex surgeries and interventions. Very often, however, researchers find the historical records of emerging surgical techniques, such as the transcatheter aortic valve replacement (TAVR), are highly scarce in quantity. In this paper, we address this challenge by proposing novel generative invertible networks (GIN) to select features and generate high-quality virtual patients that may potentially serve as an additional data source for machine learning. Combining a convolutional neural network (CNN) and generative adversarial networks (GAN), GIN discovers the pathophysiologic meaning of the feature space. Moreover, a test of predicting the surgical outcome directly using the selected features results in a high accuracy of 81.55%, which suggests little pathophysiologic information has been lost while conducting the feature selection. This demonstrates GIN can generate virtual patients not only visually authentic but also pathophysiologically interpretable

    A spatial impedance controller for robotic manipulation

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    Mechanical impedance is the dynamic generalization of stiffness, and determines interactive behavior by definition. Although the argument for explicitly controlling impedance is strong, impedance control has had only a modest impact on robotic manipulator control practice. This is due in part to the fact that it is difficult to select suitable impedances given tasks. A spatial impedance controller is presented that simplifies impedance selection. Impedance is characterized using ¿spatially affine¿ families of compliance and damping, which are characterized by nonspatial and spatial parameters. Nonspatial parameters are selected independently of configuration of the object with which the robot must interact. Spatial parameters depend on object configurations, but transform in an intuitive, well-defined way. Control laws corresponding to these compliance and damping families are derived assuming a commonly used robot model. While the compliance control law was implemented in simulation and on a real robot, this paper emphasizes the underlying theor

    Utilizing a 3D game engine to develop a virtual design review system

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    A design review process is where information is exchanged between the designers and design reviewers to resolve any potential design related issues, and to ensure that the interests and goals of the owner are met. The effective execution of design review will minimize potential errors or conflicts, reduce the time for review, shorten the project life-cycle, allow for earlier occupancy, and ultimately translate into significant total project savings to the owner. However, the current methods of design review are still heavily relying on 2D paper-based format, sequential and lack central and integrated information base for efficient exchange and flow of information. There is thus a need for the use of a new medium that allow for 3D visualization of designs, collaboration among designers and design reviewers, and early and easy access to design review information. This paper documents the innovative utilization of a 3D game engine, the Torque Game Engine as the underlying tool and enabling technology for a design review system, the Virtual Design Review System for architectural designs. Two major elements are incorporated; 1) a 3D game engine as the driving tool for the development and implementation of design review processes, and 2) a virtual environment as the medium for design review, where visualization of design and design review information is based on sound principles of GUI design. The development of the VDRS involves two major phases; firstly, the creation of the assets and the assembly of the virtual environment, and secondly, the modification of existing functions or introducing new functionality through programming of the 3D game engine in order to support design review in a virtual environment. The features that are included in the VDRS are support for database, real-time collaboration across network, viewing and navigation modes, 3D object manipulation, parametric input, GUI, and organization for 3D objects

    Early aspects: aspect-oriented requirements engineering and architecture design

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    This paper reports on the third Early Aspects: Aspect-Oriented Requirements Engineering and Architecture Design Workshop, which has been held in Lancaster, UK, on March 21, 2004. The workshop included a presentation session and working sessions in which the particular topics on early aspects were discussed. The primary goal of the workshop was to focus on challenges to defining methodical software development processes for aspects from early on in the software life cycle and explore the potential of proposed methods and techniques to scale up to industrial applications
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