Robert Porzel

Universität Bremen, Bremen, Bremen, Germany

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Publications (50)4.03 Total impact

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    ABSTRACT: Intra-operative interaction with computer systems is a challenge because of spatial constraints and also because of the need for sterility. Therefore touchless interfaces are interesting alternatives to classical interaction devices. A device that can read and convert brain signals into control and communication commands is called brain-computer-interface (BCI). In this short report we present a study on the performance of a commercial, low-cost BCI (Emotiv EPOC) for software control in surgery and intervention and examine the influence of the already existing cognitive load caused by the medical procedure itself.
    Full-text · Conference Paper · Sep 2015
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    ABSTRACT: This paper investigates the effects of se-mantic distance on the development of lexical entrainment. For this purpose, the authors developed a card game with three levels of semantic distance. The participants were asked to arrange the cards into a congruent sequential order. By increasing the semantic distance, more words were needed to solve the task and a higher rate of hypernyms was used, demonstrating lexical entrainment. Additionally, results showed that the participants recurred to the use of deentrained terms on a third stage of the conversation. Based on this we examine what this finding might entail for existing theories on linguistic alignment.
    Full-text · Conference Paper · Dec 2013
  • Robert Porzel · Adeel Naveed · Yuting Chen · Marc Herrlich
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    ABSTRACT: Enabling collaborative work on multi-touch tables comes with many challenges for the design of tabletop systems. For example, multi-touch tables have been not standardized, tabletop groupware systems are built for various purposes and the diversity of task activities constitute some of the challenges for enabling natural collaborative human computer interaction on multi-touch tables. While many studies have been conducted on individual problems, aggregate guidelines for designing an appropriate tabletop groupware system that can adapt to variable conditions are still under construction. In this paper we contribute some insights toward more general guidelines via an empirical study that sought to untangle the interrelated effects of ownership, individual collaborative strategies and workspace usage.
    No preview · Conference Paper · Jan 2013

  • No preview · Chapter · Jan 2011
  • R Porzel · T Warden · F Ganji · Markus Aust

    No preview · Conference Paper · Jan 2011
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    ABSTRACT: In this paper, we investigate how discourse context in the form of short-term memory can be exploited to automatically group consecutive strokes in digital freehand sketching. With this machine learning approach, no database of explicit object representations is used for template matching on a complete scene—instead, grouping decisions are based on limited spatio-temporal context. We employ two different classifier formalisms for this time series analysis task, namely Echo State Networks (ESNs) and Support Vector Machines (SVMs). ESNs present internal-state classifiers with inherent memory capabilities. For the conventional static SVM, short-term memory is supplied externally via fixed-length feature vector expansion. We compare the respective setup heuristics and conduct experiments with two exemplary problems. Promising results are achieved with both formalisms. Yet, our experiments indicate that using ESNs for variable-length memory tasks alleviates the risk of overfitting due to non-expressive features or improperly determined temporal embedding dimensions.
    Full-text · Conference Paper · Sep 2010
  • Robert Porzel · Tobias Warden
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    ABSTRACT: Simulation is a commonly used method, for example in economics, engineering or computer science. In many cases, simulations become difficult to design and control, especially when the simulated actors need to posses, acquire or process knowledge in some form or the other. Today simulation systems exists that are based on the multi-agent paradigm and use formal ontologies for representing the world, internal states of an agent or domain knowledge. However, such systems frequently feature individual noncongruent models that are not aligned with state of the art foundational ontology frameworks. In this work we outline a foundational simulation ontology (FSO) that models simulations themselves so that not only the domain-specific models can be aligned to a standardized upper level, but also scenario design for ontology-based simulations can be performed by applying state of the art ontology engineering principles. Our showcase scenario is that of autonomous logistic processes, where we apply our model for the domain of transport logistics. 1
    No preview · Conference Paper · Aug 2010
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    ABSTRACT: This paper presents the research activities of the Collaborative Research Centre (CRC) 637 “Autonomous Cooperating Logistic Processes—A Paradigm Shift and its Limitations” at the University of Bremen. After a motivation of autonomous logistics as an answer to current trends in increasingly dynamic markets, we sketch the structure and aims of the interdisciplinary CRC. We present several interpretations of the central motive of autonomous control, pursued by sub-projects over the course of the first project period, and focus on an agent-based approach to autonomous logistics.
    No preview · Article · Jul 2010
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    ABSTRACT: This paper presents the research activities of the Collaborative Research Centre (CRC) 637 “Autonomous Cooperating Logistic Processes—A Paradigm Shift and its Limitations” at the University of Bremen. After a motivation of autonomous logistics as an answer to current trends in increasingly dynamic markets, we sketch the structure and aims of the interdisciplinary CRC. We present several interpretations of the central motive of autonomous control, pursued by sub-projects over the course of the first project period, and focus on an agent-based approach to autonomous logistics.
    Full-text · Article · Jul 2010
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    ABSTRACT: In multiagent-based simulation systems the agent pro-gramming paradigm is adopted for simulation. This simu-lation approach offers the promise to facilitate the design and development of complex simulations, both regarding the distinct simulation actors and the simulation envi-ronment itself. We introduce the simulation middleware PlaSMA which extends the JADE agent framework with a simulation control that ensures synchronization and pro-vides a world model based on a formal ontological descrip-tion of the respective application domain. We illustrate the benefits of an ontology grounding for simulation de-sign and discuss further gains to be expected from recent advances in ontology engineering, namely the adaption of foundational ontologies and modelling-patterns.
    Full-text · Article · Jun 2010
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    ABSTRACT: Herein we describe the QuickWoZ system, a Wizard-of-Oz (WoZ) tool that allows for the remote control of the behavior of animated characters in a 3D environment. The complete scene, character, behaviors and sounds can be defined in simple XML documents, which are parsed at runtime, so that setting up an experiment can be done without programming expertise. Quick selection lists and buttons enable the wizard to easily control the agents' behavior and allow for fast reactions to the subjects' input. The system is tailored for experiments with embodied conversational agents (ECAs) featuring multimodal interaction and was designed as a rapid prototyping system for evaluating the impact of an agent's behavior on the user.
    No preview · Conference Paper · Jan 2010
  • Yuting Chen · Adeel Naveed · Robert Porzel
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    ABSTRACT: Endowing embodied conversational agent with personality affords more natural modalities for their interaction with human interlocutors. To bridge the personality gap between users and agents, we designed minimal two personalities for corresponding agents i.e. an introverted and an extroverted agent. Each features a combination of different verbal and non-verbal behaviors. In this paper, we present an examination of the effects of the speaking and behavior styles of the two agents and explore the resulting design factors pertinent for spoken dialogue systems. The results indicate that users prefer the extroverted agent to the introverted one. The personality traits of the agents influence the users' preferences, dialogues, and behavior. Statistically, it is highly significant that users are more talkative with the extroverted agent. We also investigate the spontaneous speech disfluency of the dialogues and demonstrate that the extroverted behavior model reduce the user's speech disfluency. Furthermore, users having different mental models behave differently with the agents. The results and findings show that the minimal personalities of agents maximally influence the interlocutors' behaviors.
    No preview · Conference Paper · Jan 2010
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    Rainer Malaka · Robert Porzel
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    ABSTRACT: Designing user interfaces for ubiquitous computing applications is a challenging task. In this paper we discuss how to build intelligent interfaces. The foundations are usability principles that are valid on very general levels. We present a number of established methods for the design process that can help to meet these principle requirements. In particular participatory and iterative so-called human centered approaches are important for interfaces in ubiquitous computing. In particular the question how to make interactional interfaces more intelligent is not trivial and there are multiple approaches to enhance either the intelligence of the system or that of the user. Novel interface approaches, presented herein, follow the idea of embodied interaction and put particular emphasis on the situated use of a system and the mental models humans develop in context.
    Full-text · Conference Paper · Sep 2009
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    Aneta Takhtamysheva · Robert Porzel · Markus Krause
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    ABSTRACT: The present work and demonstration system aims at finding an efficient and cost-effective human computation method to expand the linguistic capabilities of interactive games that need it to respond appropriately to the language based input of their users. As a showcase scenario for the experiments conducted, we took interactive fiction applications and examined how the human computation game design and scoring approaches affects the quality of the data gathered. The ensuing analysis of the data confirms our initial hypothesis that game approaches can provide both the qualitative and quantitative data needed for the corresponding interactive games.
    Full-text · Conference Paper · Jan 2009
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    ABSTRACT: Increased availability of mobile computing, such as personal digital assistants (PDAs), creates the potential for constant and intelligent access to up-to-date, integrated and detailed information from the Web, regardless of one's actual geographical position. Intelligent question-answering requires the representation of knowledge from various domains, such as the navigational and discourse context of the user, potential user questions, the information provided by Web services and so on, for example in the form of ontologies. Within the context of the SmartWeb project, we have developed a number of domain-specific ontologies that are relevant for mobile and intelligent user interfaces to open-domain question-answering and information services on the Web. To integrate the various domain-specific ontologies, we have developed a foundational ontology, the SmartSUMO ontology, on the basis of the DOLCE and SUMO ontologies. This allows us to combine all the developed ontologies into a single SmartWeb Integrated Ontology (SWIntO) having a common modeling basis with conceptual clarity and the provision of ontology design patterns for modeling consistency. In this paper, we present SWIntO, describe the design choices we made in its construction, illustrate the use of the ontology through a number of applications, and discuss some of the lessons learned from our experiences.
    Full-text · Article · Jul 2007 · Journal of Web Semantics
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    ABSTRACT: In this paper we address the question of how traditional approaches to modeling world knowledge, i.e. to model shared con-ceptualizations of specific domains of interest via formal ontologies, can be enhanced by a pragmatic layer to solve the problem of ex-plicating hitherto implicit information contained in the user's utter-ances and to further the assistance capabilities of dialog systems and how they can be connected to dedicated analyzers that observe top-ical contextual information. For this purpose, the notions of context and pragmatics are introduced as one of the central problems facing applications in artificial intelligence. We will argue that pragmatic inferences are impossible without contextual observations and intro-duce a model of context-adaptive processing using a combination of formal ontologies and analyzers for various types of context.
    Full-text · Article · Jan 2006
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    ABSTRACT: The SmartKom multimodal dialogue system offers access to a wide range of information and planning services. A significant subset of these are constituted by external data and service providers. The work presented herein describes the challenging task of integrating such external data and service sources to make them semantically accessible to other systems and users. We present the implemented multiagent system the corresponding knowledge-based extraction and integration approach. As a whole these agents cooperate to provide users with topical high-quality information via unified and intuitively usable interfaces such as the SmartKom system.
    No preview · Chapter · Dec 2005
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    ABSTRACT: This paper presents SmartKom-Mobile, the mobile version of the SmartKom system. SmartKom-Mobile brings together highly advanced user interaction and mobile computing in a novel way and allows for ubiquitous access to multidomain information. SmartKom-Mobile is device-independent and realizes multimodal interaction in cars and on mobile devices such as PDAs. With its siblings, SmartKom-Home and SmartKom-Public, it provides intelligent user interfaces for an extremely broad range of scenarios and environments.
    No preview · Chapter · Dec 2005
  • Iryna Gurevych · Robert Porzel
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    ABSTRACT: We present three types of data collections and their experimental paradigms. The resulting data were employed to conduct a number of annotation experiments, create evaluation gold standards and train statistical models. The data, experiments and their analyses highlight the importance of data-driven empirical laboratory and field work for research on intuitive multimodal human-computer interfaces.
    No preview · Chapter · Dec 2005
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    ABSTRACT: This chapter describes the English-language SmartKom-Mobile system and related research. We explain the work required to support a second language in SmartKom and the design of the English speech recognizer. We then discuss research carried out on signal processing methods for robust speech recognition and on language analysis using the Embodied Construction Grammar formalism. Finally, the results of human-subject experiments using a novel Wizard and Operator model are analyzed with an eye to creating more felicitous interaction in dialogue systems.
    Preview · Chapter · Dec 2005

Publication Stats

504 Citations
4.03 Total Impact Points

Institutions

  • 2007-2010
    • Universität Bremen
      Bremen, Bremen, Germany
  • 1998
    • Universität Heidelberg
      Heidelburg, Baden-Württemberg, Germany