AHCI RESEARCH GROUP
Publications
Papers published in international journals,
proceedings of conferences, workshops and books.
OUR RESEARCH
Scientific Publications
How to
You can use the tag cloud to select only the papers dealing with specific research topics.
You can expand the Abstract, Links and BibTex record for each paper.
2025
Li, H.; Wang, Z.; Liang, W.; Wang, Y.
X’s Day: Personality-Driven Virtual Human Behavior Generation Journal Article
In: IEEE Transactions on Visualization and Computer Graphics, vol. 31, no. 5, pp. 3514–3524, 2025, ISSN: 10772626 (ISSN).
Abstract | Links | BibTeX | Tags: adult, Augmented Reality, Behavior Generation, Chatbots, Computer graphics, computer interface, Contextual Scene, female, human, Human behaviors, Humans, Long-term behavior, male, Novel task, Personality, Personality traits, Personality-driven Behavior, physiology, Social behavior, User-Computer Interface, Users' experiences, Virtual agent, Virtual environments, Virtual humans, Virtual Reality, Young Adult
@article{li_xs_2025,
title = {X’s Day: Personality-Driven Virtual Human Behavior Generation},
author = {H. Li and Z. Wang and W. Liang and Y. Wang},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-105003864932&doi=10.1109%2fTVCG.2025.3549574&partnerID=40&md5=a865bbd2b0fa964a4f0f4190955dc787},
doi = {10.1109/TVCG.2025.3549574},
issn = {10772626 (ISSN)},
year = {2025},
date = {2025-01-01},
journal = {IEEE Transactions on Visualization and Computer Graphics},
volume = {31},
number = {5},
pages = {3514–3524},
abstract = {Developing convincing and realistic virtual human behavior is essential for enhancing user experiences in virtual reality (VR) and augmented reality (AR) settings. This paper introduces a novel task focused on generating long-term behaviors for virtual agents, guided by specific personality traits and contextual elements within 3D environments. We present a comprehensive framework capable of autonomously producing daily activities autoregressively. By modeling the intricate connections between personality characteristics and observable activities, we establish a hierarchical structure of Needs, Task, and Activity levels. Integrating a Behavior Planner and a World State module allows for the dynamic sampling of behaviors using large language models (LLMs), ensuring that generated activities remain relevant and responsive to environmental changes. Extensive experiments validate the effectiveness and adaptability of our approach across diverse scenarios. This research makes a significant contribution to the field by establishing a new paradigm for personalized and context-aware interactions with virtual humans, ultimately enhancing user engagement in immersive applications. Our project website is at: https://behavior.agent-x.cn/. © 2025 IEEE. All rights reserved,},
keywords = {adult, Augmented Reality, Behavior Generation, Chatbots, Computer graphics, computer interface, Contextual Scene, female, human, Human behaviors, Humans, Long-term behavior, male, Novel task, Personality, Personality traits, Personality-driven Behavior, physiology, Social behavior, User-Computer Interface, Users' experiences, Virtual agent, Virtual environments, Virtual humans, Virtual Reality, Young Adult},
pubstate = {published},
tppubtype = {article}
}
Song, T.; Pabst, F.; Eck, U.; Navab, N.
Enhancing Patient Acceptance of Robotic Ultrasound through Conversational Virtual Agent and Immersive Visualizations Journal Article
In: IEEE Transactions on Visualization and Computer Graphics, vol. 31, no. 5, pp. 2901–2911, 2025, ISSN: 10772626 (ISSN).
Abstract | Links | BibTeX | Tags: 3D reconstruction, adult, Augmented Reality, Computer graphics, computer interface, echography, female, human, Humans, Imaging, Intelligent robots, Intelligent virtual agents, Language Model, male, Medical robotics, Middle Aged, Mixed reality, Patient Acceptance of Health Care, patient attitude, Patient comfort, procedures, Real-world, Reality visualization, Robotic Ultrasound, Robotics, Three-Dimensional, three-dimensional imaging, Trust and Acceptance, Ultrasonic applications, Ultrasonic equipment, Ultrasonography, Ultrasound probes, User-Computer Interface, Virtual agent, Virtual assistants, Virtual environments, Virtual Reality, Visual languages, Visualization, Young Adult
@article{song_enhancing_2025,
title = {Enhancing Patient Acceptance of Robotic Ultrasound through Conversational Virtual Agent and Immersive Visualizations},
author = {T. Song and F. Pabst and U. Eck and N. Navab},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-105003687673&doi=10.1109%2fTVCG.2025.3549181&partnerID=40&md5=1d46569933582ecf5e967f0794aafc07},
doi = {10.1109/TVCG.2025.3549181},
issn = {10772626 (ISSN)},
year = {2025},
date = {2025-01-01},
journal = {IEEE Transactions on Visualization and Computer Graphics},
volume = {31},
number = {5},
pages = {2901–2911},
abstract = {Robotic ultrasound systems have the potential to improve medical diagnostics, but patient acceptance remains a key challenge. To address this, we propose a novel system that combines an AI-based virtual agent, powered by a large language model (LLM), with three mixed reality visualizations aimed at enhancing patient comfort and trust. The LLM enables the virtual assistant to engage in natural, conversational dialogue with patients, answering questions in any format and offering real-time reassurance, creating a more intelligent and reliable interaction. The virtual assistant is animated as controlling the ultrasound probe, giving the impression that the robot is guided by the assistant. The first visualization employs augmented reality (AR), allowing patients to see the real world and the robot with the virtual avatar superimposed. The second visualization is an augmented virtuality (AV) environment, where the real-world body part being scanned is visible, while a 3D Gaussian Splatting reconstruction of the room, excluding the robot, forms the virtual environment. The third is a fully immersive virtual reality (VR) experience, featuring the same 3D reconstruction but entirely virtual, where the patient sees a virtual representation of their body being scanned in a robot-free environment. In this case, the virtual ultrasound probe, mirrors the movement of the probe controlled by the robot, creating a synchronized experience as it touches and moves over the patient's virtual body. We conducted a comprehensive agent-guided robotic ultrasound study with all participants, comparing these visualizations against a standard robotic ultrasound procedure. Results showed significant improvements in patient trust, acceptance, and comfort. Based on these findings, we offer insights into designing future mixed reality visualizations and virtual agents to further enhance patient comfort and acceptance in autonomous medical procedures. © 1995-2012 IEEE.},
keywords = {3D reconstruction, adult, Augmented Reality, Computer graphics, computer interface, echography, female, human, Humans, Imaging, Intelligent robots, Intelligent virtual agents, Language Model, male, Medical robotics, Middle Aged, Mixed reality, Patient Acceptance of Health Care, patient attitude, Patient comfort, procedures, Real-world, Reality visualization, Robotic Ultrasound, Robotics, Three-Dimensional, three-dimensional imaging, Trust and Acceptance, Ultrasonic applications, Ultrasonic equipment, Ultrasonography, Ultrasound probes, User-Computer Interface, Virtual agent, Virtual assistants, Virtual environments, Virtual Reality, Visual languages, Visualization, Young Adult},
pubstate = {published},
tppubtype = {article}
}
Chen, J.; Wu, X.; Lan, T.; Li, B.
LLMER: Crafting Interactive Extended Reality Worlds with JSON Data Generated by Large Language Models Journal Article
In: IEEE Transactions on Visualization and Computer Graphics, vol. 31, no. 5, pp. 2715–2724, 2025, ISSN: 10772626 (ISSN).
Abstract | Links | BibTeX | Tags: % reductions, 3D modeling, algorithm, Algorithms, Augmented Reality, Coding errors, Computer graphics, Computer interaction, computer interface, Computer simulation languages, Extended reality, generative artificial intelligence, human, Human users, human-computer interaction, Humans, Imaging, Immersive, Language, Language Model, Large language model, large language models, Metadata, Natural Language Processing, Natural language processing systems, Natural languages, procedures, Script generation, Spatio-temporal data, Three dimensional computer graphics, Three-Dimensional, three-dimensional imaging, User-Computer Interface, Virtual Reality
@article{chen_llmer_2025,
title = {LLMER: Crafting Interactive Extended Reality Worlds with JSON Data Generated by Large Language Models},
author = {J. Chen and X. Wu and T. Lan and B. Li},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-105003825793&doi=10.1109%2fTVCG.2025.3549549&partnerID=40&md5=da4681d0714548e3a7e0c8c3295d2348},
doi = {10.1109/TVCG.2025.3549549},
issn = {10772626 (ISSN)},
year = {2025},
date = {2025-01-01},
journal = {IEEE Transactions on Visualization and Computer Graphics},
volume = {31},
number = {5},
pages = {2715–2724},
abstract = {The integration of Large Language Models (LLMs) like GPT-4 with Extended Reality (XR) technologies offers the potential to build truly immersive XR environments that interact with human users through natural language, e.g., generating and animating 3D scenes from audio inputs. However, the complexity of XR environments makes it difficult to accurately extract relevant contextual data and scene/object parameters from an overwhelming volume of XR artifacts. It leads to not only increased costs with pay-per-use models, but also elevated levels of generation errors. Moreover, existing approaches focusing on coding script generation are often prone to generation errors, resulting in flawed or invalid scripts, application crashes, and ultimately a degraded user experience. To overcome these challenges, we introduce LLMER, a novel framework that creates interactive XR worlds using JSON data generated by LLMs. Unlike prior approaches focusing on coding script generation, LLMER translates natural language inputs into JSON data, significantly reducing the likelihood of application crashes and processing latency. It employs a multi-stage strategy to supply only the essential contextual information adapted to the user's request and features multiple modules designed for various XR tasks. Our preliminary user study reveals the effectiveness of the proposed system, with over 80% reduction in consumed tokens and around 60% reduction in task completion time compared to state-of-the-art approaches. The analysis of users' feedback also illuminates a series of directions for further optimization. © 1995-2012 IEEE.},
keywords = {% reductions, 3D modeling, algorithm, Algorithms, Augmented Reality, Coding errors, Computer graphics, Computer interaction, computer interface, Computer simulation languages, Extended reality, generative artificial intelligence, human, Human users, human-computer interaction, Humans, Imaging, Immersive, Language, Language Model, Large language model, large language models, Metadata, Natural Language Processing, Natural language processing systems, Natural languages, procedures, Script generation, Spatio-temporal data, Three dimensional computer graphics, Three-Dimensional, three-dimensional imaging, User-Computer Interface, Virtual Reality},
pubstate = {published},
tppubtype = {article}
}
Stacchio, L.; Balloni, E.; Frontoni, E.; Paolanti, M.; Zingaretti, P.; Pierdicca, R.
MineVRA: Exploring the Role of Generative AI-Driven Content Development in XR Environments through a Context-Aware Approach Journal Article
In: IEEE Transactions on Visualization and Computer Graphics, vol. 31, no. 5, pp. 3602–3612, 2025, ISSN: 10772626 (ISSN).
Abstract | Links | BibTeX | Tags: adult, Article, Artificial intelligence, Computer graphics, Computer vision, Content Development, Contents development, Context-Aware, Context-aware approaches, Extended reality, female, Generative adversarial networks, Generative AI, generative artificial intelligence, human, Human-in-the-loop, Immersive, Immersive environment, male, Multi-modal, User need, Virtual environments, Virtual Reality
@article{stacchio_minevra_2025,
title = {MineVRA: Exploring the Role of Generative AI-Driven Content Development in XR Environments through a Context-Aware Approach},
author = {L. Stacchio and E. Balloni and E. Frontoni and M. Paolanti and P. Zingaretti and R. Pierdicca},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-105003746367&doi=10.1109%2fTVCG.2025.3549160&partnerID=40&md5=70b162b574eebbb0cb71db871aa787e1},
doi = {10.1109/TVCG.2025.3549160},
issn = {10772626 (ISSN)},
year = {2025},
date = {2025-01-01},
journal = {IEEE Transactions on Visualization and Computer Graphics},
volume = {31},
number = {5},
pages = {3602–3612},
abstract = {The convergence of Artificial Intelligence (AI), Computer Vision (CV), Computer Graphics (CG), and Extended Reality (XR) is driving innovation in immersive environments. A key challenge in these environments is the creation of personalized 3D assets, traditionally achieved through manual modeling, a time-consuming process that often fails to meet individual user needs. More recently, Generative AI (GenAI) has emerged as a promising solution for automated, context-aware content generation. In this paper, we present MineVRA (Multimodal generative artificial iNtelligence for contExt-aware Virtual Reality Assets), a novel Human-In-The-Loop (HITL) XR framework that integrates GenAI to facilitate coherent and adaptive 3D content generation in immersive scenarios. To evaluate the effectiveness of this approach, we conducted a comparative user study analyzing the performance and user satisfaction of GenAI-generated 3D objects compared to those generated by Sketchfab in different immersive contexts. The results suggest that GenAI can significantly complement traditional 3D asset libraries, with valuable design implications for the development of human-centered XR environments. © 1995-2012 IEEE.},
keywords = {adult, Article, Artificial intelligence, Computer graphics, Computer vision, Content Development, Contents development, Context-Aware, Context-aware approaches, Extended reality, female, Generative adversarial networks, Generative AI, generative artificial intelligence, human, Human-in-the-loop, Immersive, Immersive environment, male, Multi-modal, User need, Virtual environments, Virtual Reality},
pubstate = {published},
tppubtype = {article}
}
2024
Pooryousef, V.; Cordeil, M.; Besançon, L.; Bassed, R.; Dwyer, T.
Collaborative Forensic Autopsy Documentation and Supervised Report Generation using a Hybrid Mixed-Reality Environment and Generative AI Journal Article
In: IEEE Transactions on Visualization and Computer Graphics, vol. 30, no. 11, pp. 7452–7462, 2024, ISSN: 10772626 (ISSN).
Abstract | Links | BibTeX | Tags: Artificial intelligence, Augmented Reality, Autopsy, Causes of death, Complex procedure, Computer graphics, computer interface, Data visualization, Digital forensics, Documentation, Forensic autopsy, Forensic engineering, Forensic investigation, forensic science, Forensic Sciences, Generative AI, human, Humans, Imaging, Information Management, Laws and legislation, Mixed reality, Mixed-reality environment, Post mortem imaging, procedures, Report generation, Three-Dimensional, three-dimensional imaging, User-Computer Interface, Visualization, Workflow
@article{pooryousef_collaborative_2024,
title = {Collaborative Forensic Autopsy Documentation and Supervised Report Generation using a Hybrid Mixed-Reality Environment and Generative AI},
author = {V. Pooryousef and M. Cordeil and L. Besançon and R. Bassed and T. Dwyer},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85204066202&doi=10.1109%2fTVCG.2024.3456212&partnerID=40&md5=d1abaf1aaf3b033df21067ea34b8b98a},
doi = {10.1109/TVCG.2024.3456212},
issn = {10772626 (ISSN)},
year = {2024},
date = {2024-01-01},
journal = {IEEE Transactions on Visualization and Computer Graphics},
volume = {30},
number = {11},
pages = {7452–7462},
abstract = {—Forensic investigation is a complex procedure involving experts working together to establish cause of death and report findings to legal authorities. While new technologies are being developed to provide better post-mortem imaging capabilities—including mixed-reality (MR) tools to support 3D visualisation of such data—these tools do not integrate seamlessly into their existing collaborative workflow and report authoring process, requiring extra steps, e.g. to extract imagery from the MR tool and combine with physical autopsy findings for inclusion in the report. Therefore, in this work we design and evaluate a new forensic autopsy report generation workflow and present a novel documentation system using hybrid mixed-reality approaches to integrate visualisation, voice and hand interaction, as well as collaboration and procedure recording. Our preliminary findings indicate that this approach has the potential to improve data management, aid reviewability, and thus, achieve more robust standards. Further, it potentially streamlines report generation and minimise dependency on external tools and assistance, reducing autopsy time and related costs. This system also offers significant potential for education. A free copy of this paper and all supplemental materials are available at https://osf.io/ygfzx. © 2024 IEEE.},
keywords = {Artificial intelligence, Augmented Reality, Autopsy, Causes of death, Complex procedure, Computer graphics, computer interface, Data visualization, Digital forensics, Documentation, Forensic autopsy, Forensic engineering, Forensic investigation, forensic science, Forensic Sciences, Generative AI, human, Humans, Imaging, Information Management, Laws and legislation, Mixed reality, Mixed-reality environment, Post mortem imaging, procedures, Report generation, Three-Dimensional, three-dimensional imaging, User-Computer Interface, Visualization, Workflow},
pubstate = {published},
tppubtype = {article}
}
Rozo-Torres, A.; Sarmiento, W. J.
Coffee Masterclass: An Experience of Co-Creation with Prompt Engineering and Generative AI for Immersive Environments Development Proceedings Article
In: Proc. - IEEE Conf. Virtual Real. 3D User Interfaces Abstr. Workshops, VRW, pp. 1170–1171, Institute of Electrical and Electronics Engineers Inc., 2024, ISBN: 979-835037449-0 (ISBN).
Abstract | Links | BibTeX | Tags: Artificial intelligence, Artificial intelligence tools, Co-creation, Computer graphics, Computing methodologies, Design and development process, Development teams, Graphic system, Graphics interface, Graphics systems and interfaces, Immersive, Immersive environment, Mixed/augmented reality
@inproceedings{rozo-torres_coffee_2024,
title = {Coffee Masterclass: An Experience of Co-Creation with Prompt Engineering and Generative AI for Immersive Environments Development},
author = {A. Rozo-Torres and W. J. Sarmiento},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85195576520&doi=10.1109%2fVRW62533.2024.00379&partnerID=40&md5=f07b66f849aaa1c4d9b2e2ea79c57cf8},
doi = {10.1109/VRW62533.2024.00379},
isbn = {979-835037449-0 (ISBN)},
year = {2024},
date = {2024-01-01},
booktitle = {Proc. - IEEE Conf. Virtual Real. 3D User Interfaces Abstr. Workshops, VRW},
pages = {1170–1171},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {This work presents the design and development process of an immersive experience applying a co-creation approach between humans and generative artificial intelligence tools. From the point of view of any user, Coffee Masterclass is an immersive experience that brings anyone to the art and pleasure of preparing specialty coffees. However, the Coffee Masterclass is the result of the inclusion of prompt engineering outputs in each stage of the building process. The co-creation approach is included in all development processes, i.e., from the narrative to the visual content generated through code writing, which has been co-created between the creative team and GenAI. This work tells details of this approach, including how the generative artificial intelligence tools were used in each stage of immersive experience development. This work shows the advantage of involvement in a development team of people with skills in prompt engineering and interaction with Large Language Models. Also, it includes recommendations to other development teams, including generative artificial intelligence tools by future developments. © 2024 IEEE.},
keywords = {Artificial intelligence, Artificial intelligence tools, Co-creation, Computer graphics, Computing methodologies, Design and development process, Development teams, Graphic system, Graphics interface, Graphics systems and interfaces, Immersive, Immersive environment, Mixed/augmented reality},
pubstate = {published},
tppubtype = {inproceedings}
}
2023
Dipanda, Albert; Gallo, Luigi; Yetongnon, Kokou (Ed.)
2023 17th International Conference on Signal-Image Technology & Internet-Based Systems (SITIS) Proceedings
IEEE Computer Society, 2023, ISBN: 979-8-3503-7091-1.
Abstract | Links | BibTeX | Tags: Computer graphics, Image processing
@proceedings{dipanda202317thInternational2023,
title = {2023 17th International Conference on Signal-Image Technology & Internet-Based Systems (SITIS)},
editor = { Albert Dipanda and Luigi Gallo and Kokou Yetongnon},
url = {https://ieeexplore.ieee.org/servlet/opac?punumber=10472709},
doi = {10.1109/SITIS61268.2023},
isbn = {979-8-3503-7091-1},
year = {2023},
date = {2023-11-10},
urldate = {2024-03-21},
publisher = {IEEE Computer Society},
abstract = {We are pleased to welcome you to SITIS 2023, the seventeenth edition of the IEEE International Conference on Signal-Image Technology & Internet-Based Systems. We thank the authors for their valuable contributions to the conference. SITIS 2023 aims to bring together researchers from the major communities of signal/image processing and information modeling and analysis, and to foster crossdisciplinary collaborations. The conference consists of two tracks: SIVT (Signal & Image and Vision Technology), which focuses on recent developments and evolutions in signal processing, image analysis, vision, coding & authentication, and retrieval techniques; and ISSA (Intelligent Systems Services and Applications), which covers emerging concepts, architectures, protocols, and methodologies for data management on the Web and the Internet of Things technologies that connect unlimited numbers of smart objects. In addition to these tracks, SITIS 2023 also features some workshops that address a wide range of related but more specific topics.},
keywords = {Computer graphics, Image processing},
pubstate = {published},
tppubtype = {proceedings}
}
Dipanda, Albert; Gallo, Luigi; Yetongnon, Kokou (Ed.)
2023 17th International Conference on Signal-Image Technology & Internet-Based Systems (SITIS) Book
IEEE Computer Society, 2023, ISBN: 979-8-3503-7091-1, (tex.referencetype: proceedings).
Abstract | Links | BibTeX | Tags: Computer graphics, Image processing
@book{dipanda_2023_2023,
title = {2023 17th International Conference on Signal-Image Technology & Internet-Based Systems (SITIS)},
editor = {Albert Dipanda and Luigi Gallo and Kokou Yetongnon},
url = {https://ieeexplore.ieee.org/servlet/opac?punumber=10472709},
isbn = {979-8-3503-7091-1},
year = {2023},
date = {2023-11-01},
publisher = {IEEE Computer Society},
abstract = {We are pleased to welcome you to SITIS 2023, the seventeenth edition of the IEEE International
Conference on Signal-Image Technology & Internet-Based Systems. We thank the authors for their
valuable contributions to the conference. SITIS 2023 aims to bring together researchers from the major
communities of signal/image processing and information modeling and analysis, and to foster crossdisciplinary
collaborations. The conference consists of two tracks: SIVT (Signal & Image and Vision
Technology), which focuses on recent developments and evolutions in signal processing, image
analysis, vision, coding & authentication, and retrieval techniques; and ISSA (Intelligent Systems
Services and Applications), which covers emerging concepts, architectures, protocols, and
methodologies for data management on the Web and the Internet of Things technologies that connect
unlimited numbers of smart objects. In addition to these tracks, SITIS 2023 also features some
workshops that address a wide range of related but more specific topics.},
note = {tex.referencetype: proceedings},
keywords = {Computer graphics, Image processing},
pubstate = {published},
tppubtype = {book}
}
Conference on Signal-Image Technology & Internet-Based Systems. We thank the authors for their
valuable contributions to the conference. SITIS 2023 aims to bring together researchers from the major
communities of signal/image processing and information modeling and analysis, and to foster crossdisciplinary
collaborations. The conference consists of two tracks: SIVT (Signal & Image and Vision
Technology), which focuses on recent developments and evolutions in signal processing, image
analysis, vision, coding & authentication, and retrieval techniques; and ISSA (Intelligent Systems
Services and Applications), which covers emerging concepts, architectures, protocols, and
methodologies for data management on the Web and the Internet of Things technologies that connect
unlimited numbers of smart objects. In addition to these tracks, SITIS 2023 also features some
workshops that address a wide range of related but more specific topics.
2013
Franchini, Silvia; Gentile, Antonio; Sorbello, Filippo; Vassallo, Giorgio; Vitabile, Salvatore
Design and Implementation of an Embedded Coprocessor with Native Support for 5D, Quadruple-Based Clifford Algebra Journal Article
In: IEEE Transactions on Computers, vol. 62, no. 12, pp. 2366–2381, 2013, ISSN: 0018-9340.
Abstract | Links | BibTeX | Tags: Application-specific processors, Clifford algebra, Computational geometry, Computer graphics, Embedded coprocessors, Field Programmable Gate Arrays, FPGA prototyping, Geometric algebra, inverse kinematics, Motion capture, Raytracing, robotic arm, Robotics
@article{franchiniDesignImplementationEmbedded2013,
title = {Design and Implementation of an Embedded Coprocessor with Native Support for 5D, Quadruple-Based Clifford Algebra},
author = { Silvia Franchini and Antonio Gentile and Filippo Sorbello and Giorgio Vassallo and Salvatore Vitabile},
doi = {10.1109/TC.2012.225},
issn = {0018-9340},
year = {2013},
date = {2013-01-01},
journal = {IEEE Transactions on Computers},
volume = {62},
number = {12},
pages = {2366--2381},
abstract = {Geometric or Clifford algebra (CA) is a powerful mathematical tool that offers a natural and intuitive way to model geometric facts in a number of research fields, such as robotics, machine vision, and computer graphics. Operating in higher dimensional spaces, its practical use is hindered, however, by a significant computational cost, only partially addressed by dedicated software libraries and hardware/software codesigns. For low-dimensional algebras, several dedicated hardware accelerators and coprocessing architectures have been already proposed in the literature. This paper introduces the architecture of CliffordALU5, an embedded coprocessing core conceived for native execution of up to 5D CA operations. CliffordALU5 exploits a novel, hardware-oriented representation of the algebra elements that allows for faster execution of Clifford operations. In this paper, a prototype implementation of a complete system-on-chip (SOC) based on CliffordALU5 is presented. This prototype integrates an embedded processing soft-core based on the PowerPC 405 and a CliffordALU5 coprocessor on a Xilinx XUPV2P Field Programmable Gate Array (FPGA) board. Test results show a 5texttimes average speedup for 4D Clifford products and a 4texttimes average speedup for 5D Clifford products against the same operations in Gaigen 2, a CA software library generator running on the general-purpose PowerPC processor. This paper also presents an execution analysis of three different applications in three diverse domains, namely, inverse kinematics of a robot, optical motion capture, and raytracing, showing an average speedup between 3texttimes and 4texttimes with respect to the baseline Gaigen 2 implementation. Finally, a multicore approach to higher dimensional CA based on CliffordALU5 is discussed. textcopyright 1968-2012 IEEE.},
keywords = {Application-specific processors, Clifford algebra, Computational geometry, Computer graphics, Embedded coprocessors, Field Programmable Gate Arrays, FPGA prototyping, Geometric algebra, inverse kinematics, Motion capture, Raytracing, robotic arm, Robotics},
pubstate = {published},
tppubtype = {article}
}
Franchini, Silvia; Gentile, Antonio; Sorbello, Filippo; Vassallo, Giorgio; Vitabile, Salvatore
Design and implementation of an embedded coprocessor with native support for 5D, quadruple-based clifford algebra Journal Article
In: IEEE Transactions on Computers, vol. 62, no. 12, pp. 2366–2381, 2013, ISSN: 0018-9340.
Abstract | Links | BibTeX | Tags: Application-specific processors, Clifford algebra, Computational geometry, Computer graphics, Embedded coprocessors, Field Programmable Gate Arrays, FPGA prototyping, Geometric algebra, inverse kinematics, Motion capture, Raytracing, robotic arm, Robotics
@article{franchini_design_2013,
title = {Design and implementation of an embedded coprocessor with native support for 5D, quadruple-based clifford algebra},
author = {Silvia Franchini and Antonio Gentile and Filippo Sorbello and Giorgio Vassallo and Salvatore Vitabile},
doi = {10.1109/TC.2012.225},
issn = {0018-9340},
year = {2013},
date = {2013-01-01},
journal = {IEEE Transactions on Computers},
volume = {62},
number = {12},
pages = {2366–2381},
abstract = {Geometric or Clifford algebra (CA) is a powerful mathematical tool that offers a natural and intuitive way to model geometric facts in a number of research fields, such as robotics, machine vision, and computer graphics. Operating in higher dimensional spaces, its practical use is hindered, however, by a significant computational cost, only partially addressed by dedicated software libraries and hardware/software codesigns. For low-dimensional algebras, several dedicated hardware accelerators and coprocessing architectures have been already proposed in the literature. This paper introduces the architecture of CliffordALU5, an embedded coprocessing core conceived for native execution of up to 5D CA operations. CliffordALU5 exploits a novel, hardware-oriented representation of the algebra elements that allows for faster execution of Clifford operations. In this paper, a prototype implementation of a complete system-on-chip (SOC) based on CliffordALU5 is presented. This prototype integrates an embedded processing soft-core based on the PowerPC 405 and a CliffordALU5 coprocessor on a Xilinx XUPV2P Field Programmable Gate Array (FPGA) board. Test results show a 5× average speedup for 4D Clifford products and a 4× average speedup for 5D Clifford products against the same operations in Gaigen 2, a CA software library generator running on the general-purpose PowerPC processor. This paper also presents an execution analysis of three different applications in three diverse domains, namely, inverse kinematics of a robot, optical motion capture, and raytracing, showing an average speedup between 3× and 4× with respect to the baseline Gaigen 2 implementation. Finally, a multicore approach to higher dimensional CA based on CliffordALU5 is discussed. © 1968-2012 IEEE.},
keywords = {Application-specific processors, Clifford algebra, Computational geometry, Computer graphics, Embedded coprocessors, Field Programmable Gate Arrays, FPGA prototyping, Geometric algebra, inverse kinematics, Motion capture, Raytracing, robotic arm, Robotics},
pubstate = {published},
tppubtype = {article}
}
2011
Franchini, Silvia; Gentile, Antonio; Sorbello, Filippo; Vassallo, Giorgio; Vitabile, Salvatore
A New Embedded Coprocessor for Clifford Algebra Based Software Intensive Systems Proceedings Article
In: pp. 335–342, 2011, ISBN: 978-0-7695-4373-4.
Abstract | Links | BibTeX | Tags: Clifford algebra, Computational geometry, Compute-intensive algorithms, Computer graphics, Embedded coprocessors, Field Programmable Gate Arrays, FPGA prototyping, Geometric algebra, Software intensive systems
@inproceedings{franchiniNewEmbeddedCoprocessor2011,
title = {A New Embedded Coprocessor for Clifford Algebra Based Software Intensive Systems},
author = { Silvia Franchini and Antonio Gentile and Filippo Sorbello and Giorgio Vassallo and Salvatore Vitabile},
doi = {10.1109/CISIS.2011.55},
isbn = {978-0-7695-4373-4},
year = {2011},
date = {2011-01-01},
pages = {335--342},
abstract = {Computer graphics applications require efficient tools to model geometric objects and their transformations. Clifford algebra (also known as geometric algebra) is receiving a growing attention in many research fields, such as computer graphics, machine vision and robotics, as a new, interesting computational paradigm that offers a natural and intuitive way to perform geometric calculations. At the same time, compute-intensive graphics algorithms require the execution of million Clifford operations. Clifford algebra based software intensive systems need therefore the support of specialized hardware architectures capable of accelerating Clifford operations execution. In this paper the architecture of CliffoSorII (Clifford coprocessor II), an embedded coprocessor that offers direct hardware support to Clifford algebra operations, is introduced. The coprocessor has been designed, implemented and tested on a Field Programmable Gate Array (FPGA) board. The experimental results show the potential to achieve a 20x speedup for Clifford sums and differences and a 5x speedup for Clifford products against the analogous operations in Gaigen, a standard geometric algebra software library generator for general purpose processors. An execution analysis of a ray tracing application is also presented. textcopyright 2011 IEEE.},
keywords = {Clifford algebra, Computational geometry, Compute-intensive algorithms, Computer graphics, Embedded coprocessors, Field Programmable Gate Arrays, FPGA prototyping, Geometric algebra, Software intensive systems},
pubstate = {published},
tppubtype = {inproceedings}
}
Franchini, Silvia; Gentile, Antonio; Sorbello, Filippo; Vassallo, Giorgio; Vitabile, Salvatore
A new embedded coprocessor for Clifford Algebra based software intensive systems Proceedings Article
In: pp. 335–342, 2011, ISBN: 978-0-7695-4373-4.
Abstract | Links | BibTeX | Tags: Clifford algebra, Computational geometry, Compute-intensive algorithms, Computer graphics, Embedded coprocessors, Field Programmable Gate Arrays, FPGA prototyping, Geometric algebra, Software intensive systems
@inproceedings{franchini_new_2011,
title = {A new embedded coprocessor for Clifford Algebra based software intensive systems},
author = {Silvia Franchini and Antonio Gentile and Filippo Sorbello and Giorgio Vassallo and Salvatore Vitabile},
doi = {10.1109/CISIS.2011.55},
isbn = {978-0-7695-4373-4},
year = {2011},
date = {2011-01-01},
pages = {335–342},
abstract = {Computer graphics applications require efficient tools to model geometric objects and their transformations. Clifford algebra (also known as geometric algebra) is receiving a growing attention in many research fields, such as computer graphics, machine vision and robotics, as a new, interesting computational paradigm that offers a natural and intuitive way to perform geometric calculations. At the same time, compute-intensive graphics algorithms require the execution of million Clifford operations. Clifford algebra based software intensive systems need therefore the support of specialized hardware architectures capable of accelerating Clifford operations execution. In this paper the architecture of CliffoSorII (Clifford coprocessor II), an embedded coprocessor that offers direct hardware support to Clifford algebra operations, is introduced. The coprocessor has been designed, implemented and tested on a Field Programmable Gate Array (FPGA) board. The experimental results show the potential to achieve a 20x speedup for Clifford sums and differences and a 5x speedup for Clifford products against the analogous operations in Gaigen, a standard geometric algebra software library generator for general purpose processors. An execution analysis of a ray tracing application is also presented. © 2011 IEEE.},
keywords = {Clifford algebra, Computational geometry, Compute-intensive algorithms, Computer graphics, Embedded coprocessors, Field Programmable Gate Arrays, FPGA prototyping, Geometric algebra, Software intensive systems},
pubstate = {published},
tppubtype = {inproceedings}
}