Mental vision:a computer graphics platform for virtual reality, science and education

Despite the wide amount of computer graphics frameworks and solutions available for virtual reality, it is still difficult to find a perfect one fitting at the same time the many constraints of research and educational contexts. Advanced functionalities and user-friendliness, rendering speed and portability, or scalability and image quality are opposite characteristics rarely found into a same approach. Furthermore, fruition of virtual reality specific devices like CAVEs or wearable systems is limited by their costs and accessibility, being most of these innovations reserved to institutions and specialists able to afford and manage them through strong background knowledge in programming. Finally, computer graphics and virtual reality are a complex and difficult matter to learn, due to the heterogeneity of notions a developer needs to practice with before attempting to implement a full virtual environment. In this thesis we describe our contributions to these topics, assembled in what we called the Mental Vision platform. Mental Vision is a framework composed of three main entities. First, a teaching/research oriented graphics engine, simplifying access to 2D/3D real-time rendering on mobile devices, personal computers and CAVE systems. Second, a series of pedagogical modules to introduce and practice computer graphics and virtual reality techniques. Third, two advanced VR systems: a wearable, lightweight and handsfree mixed reality setup, and a four sides CAVE designed through off the shelf hardware. In this dissertation we explain our conceptual, architectural and technical approach, pointing out how we managed to create a robust and coherent solution reducing complexity related to cross-platform and multi-device 3D rendering, and answering simultaneously to contradictory common needs of computer graphics and virtual reality for researchers and students. A series of case studies evaluates how Mental Vision concretely satisfies these needs and achieves its goals on in vitro benchmarks and in vivo scientific and educational projects

Towards Scalable Service Composition on Multicores

Abstract. The advent of modern multicore machines, comprising several chip multi-processors each offering multiple cores and often featuring a large shared cache, offers the opportunity to redesign the architecture of service composition engines in order to take full advantage of the underlying hardware resources. In this paper we introduce an innovative service composition engine architecture, which takes into account specific features of multicore machines while not being constrained to run on any particular processor architecture. Our preliminary performance evaluation results show that the system can scale to run thousands of concurrent business process instances per second

Design and Implementation of a wearable, context-aware MR framework for the Chloe@University application

In this paper, we present the technical details and the challenges we faced during the development and evaluation phases of our wearable indoor guiding system which consists of a virtual personal assistant guiding the user to his/her desired destination. The main issues that will be discussed can be classified in three categories: context detection, real-time 3D rendering and user interaction

A virtual 3D mobile guide in the INTERMEDIA project

In this paper, we introduce a European research project, interactive media with personal networked devices (INTERMEDIA) in which we seek to progress beyond home and device-centric convergence toward truly user-centric convergence of multimedia. Our vision is to make the user the multimedia center: the user as the point at which multimedia services and the means for interacting with them converge. This paper proposes the main research goals in providing users with a personalized interface and content independent of physical networked devices, and space and time. As a case study, we describe an indoors, mobile mixed reality guide system: Chloe@University. With a see-through head-mounted display (HMD) connected to a small wearable computing device, Chloe@University provides users with an efficient way to guide someone in a building. A 3D virtual character in front of the user guides him/her to the required destinatio

A virtual 3D mobile guide in the INTERMEDIA project

In this paper, we introduce a European research project, interactive media with personal networked devices (INTERMEDIA) in which we seek to progress beyond home and device-centric convergence toward truly user-centric convergence of multimedia. Our vision is to make the user the multimedia center: the user as the point at which multimedia services and the means for interacting with them converge. This paper proposes the main research goals in providing users with a personalized interface and content independent of physical networked devices, and space and time. As a case study, we describe an indoors, mobile mixed reality guide system: Chloe@University. With a see-through head-mounted display (HMD) connected to a small wearable computing device, Chloe@University provides users with an efficient way to guide someone in a building. A 3D virtual character in front of the user guides him/her to the required destination

Chloe@University: An indoor, HMD-based mobile mixed reality guide

This paper describes an indoors, mobile mixed reality guide system: Chloe@University. With a see-through head-mounted display (HMD) connected to a hidden small computing device, Chloe@University provides users with an efficient way of guiding in a building. Augmented 3D virtual character in front of a user guides him/her to destination so that he/she can just follow the virtual guide after the user gives a voice command with desired destination to it. The most suitable virtual character is selected depending on a user’s preference for personalized service. For adapting to different indoor environments, the proposed system integrates various localization approaches. In addition, it supports different access right to a building map based on user profiles and security level

The Mental Vision framework - A platform for teaching, practicing and researching with computer graphics and virtual reality

Despite the wide amount of computer graphics frameworks and solutions available, it is still difficult to find a perfect one fitting at the same time many constraints, like pedagogical intents and user-friendliness or speed with high rendering quality and portability. In this article we describe our contribution to the topic: the Mental Vision platform. Mental Vision is a framework composed of a teaching/research oriented graphics engine simplifying the users needs in computer visualization and a set of corollary tools specifically designed for practicing and learning of computer graphics and virtual reality. In this dissertation we explain our approach design and the contribution brought into a series of study cases to show how concretely Mental Vision satisfies existing needs not addressed by other solutions

Exploiting Multicores to Optimize Business Process Execution

Abstract—While modern CPUs offer an increasing number of cores with shared caches, prevailing execution engines for business processes, workflows, or Web service compositions have not been optimized for properly exploiting the abundant processing resources of such CPUs. One factor limiting performance is the inefficient thread scheduling by the operating system, which can result in suboptimal use of shared caches. In this paper we study performance of the JOpera business process execution engine on a recent multicore machine. By analyzing the engine’s architecture and by binding threads that are likely to access shared data to cores with a common cache, we achieve speedups up to 13 % for a variety of workloads, without modifying the engine’s architecture and implementation, apart from binding threads to CPUs. As the engine is implemented in Java, we provide a new Java library to manage thread bindings and hardware performance counters. We also leverage hardware performance counters to explain the observed speedup in our performance analysis. Keywords-Business process execution engines; multicores; performance optimization; thread–CPU bindings; hardware performance counters I