Publications

@inproceedings{marsella_modeling_2003,

title = {Modeling Coping Behaviors in Virtual Humans: Don't worry, Be Happy},

author = {Stacy C. Marsella and Jonathan Gratch},

url = {http://ict.usc.edu/pubs/Modeling%20Coping%20Behavior%20in%20Virtual%20Humans-%20Dont%20worry%20Be%20happy.pdf},

year  = {2003},

date = {2003-01-01},

booktitle = {International Conference on Autonomous Agents and Multiagent Systems (AAMAS)},

pages = {313–320},

address = {Melbourne, Australia},

abstract = {This article builds on insights into how humans cope with emotion to guide the design of virtual humans. Although coping is increasingly viewed in the psychological literature as having a central role in human adaptive behavior, it has been largely ignored in computational models of emotion. In this paper, we show how psychological research on the interplay between human emotion, cognition and coping behavior can serve as a central organizing principle for the behavior of human-like autonomous agents. We present a detailed domain-independent model of coping based on this framework that significantly extends our previous work. We argue that this perspective provides novel insights into realizing adaptive behavior.},

keywords = {Social Simulation, Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{gardner_linear_2003,

title = {Linear Light Source Reflectometry},

author = {Andrew Gardner and Chris Tchou and Tim Hawkins and Paul Debevec},

url = {http://ict.usc.edu/pubs/Linear%20Light%20Source%20Reflectometry.pdf},

year  = {2003},

date = {2003-01-01},

booktitle = {ACM Transactions on Graphics},

abstract = {This paper presents a technique for estimating the spatially-varying reflectance properties of a surface based on its appearance during a single pass of a linear light source. By using a linear light rather than a point light source as the illuminant, we are able to reliably observe and estimate the diffuse color, specular color, and specular roughness of each point of the surface. The reflectometry apparatus we use is simple and inexpensive to build, requiring a single direction of motion for the light source and a fixed camera viewpoint. Our model fitting technique first renders a reflectance table of how diffuse and specular reflectance lobes would appear under moving linear light source illumination. Then, for each pixel we compare its series of intensity values to the tabulated reflectance lobes to determine which reflectance model parameters most closely produce the observed reflectance values. Using two passes of the linear light source at different angles, we can also estimate per-pixel surface normals as well as the reflectance parameters. Additionally our system records a per-pixel height map for the object and estimates its per-pixel translucency. We produce real-time renderings of the captured objects using a custom hardware shading algorithm. We apply the technique to a test object exhibiting a variety of materials as well as to an illuminated manuscript with gold lettering. To demonstrate the technique's accuracy, we compare renderings of the captured models to real photographs of the original objects.},

keywords = {Graphics},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{gratch_automating_2003,

title = {Automating After Action Review: Attributing Blame or Credit in Team Training},

author = {Jonathan Gratch and Wenji Mao},

url = {http://ict.usc.edu/pubs/Automating%20After%20Action%20Review-%20Attributing%20Blame%20or%20Credit%20in%20Team%20Training.pdf},

year  = {2003},

date = {2003-01-01},

booktitle = {Proceedings of the 12th Conference on Behavior Representation in Modeling and Simulation},

address = {Scottsdale, AZ},

abstract = {Social credit assignment is a process of social judgment whereby one singles out individuals to blame or credit for multi-agent activities. Such judgments are a key aspect of social intelligence and underlie social planning, social learning, natural language pragmatics and computational models of emotion. Based on psychological attribution theory, this paper presents a preliminary computational approach to forming such judgments based on an agent's causal knowledge and conversation interactions.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{mao_social_2003-1,

title = {The Social Credit Assignment Problem},

author = {Wenji Mao and Jonathan Gratch},

url = {http://ict.usc.edu/pubs/The%20Social%20Credit%20Assignment%20Problem.pdf},

year  = {2003},

date = {2003-01-01},

booktitle = {Lecture Notes in Computer Science; Proceedings of the 4th International Workshop on Intelligent Virtual Agents (IVA)},

volume = {2792},

address = {Kloster Irsee, Germany},

abstract = {Social credit assignment is a process of social judgment whereby one singles out individuals to blame or credit for multi-agent activities. Such judgments are a key aspect of social intelligence and underlie social planning, social learning, natural language pragmatics and computational models of emotion. Based on psychological attribution theory, this paper presents a preliminary computational approach to forming such judgments based on an agent's causal knowledge and conversation interactions.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{cao_unsupervised_2003,

title = {Unsupervised Learning for Speech Motion Editing},

author = {Yong Cao and Petros Faloutsos and Frédéric Pighin},

url = {http://ict.usc.edu/pubs/Unsupervised%20Learning%20for%20Speech%20Motion%20Editing.pdf},

year  = {2003},

date = {2003-01-01},

booktitle = {Proceedings of Eurographics/SIGGRAPH Symposium on Computer Animation},

abstract = {We present a new method for editing speech related facial motions. Our method uses an unsupervised learning technique, Independent Component Analysis (ICA), to extract a set of meaningful parameters without any annotation of the data. With ICA, we are able to solve a blind source separation problem and describe the original data as a linear combination of two sources. One source captures content (speech) and the other captures style (emotion). By manipulating the independent components we can edit the motions in intuitive ways.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{shapiro_hybrid_2003,

title = {Hybrid Control For Interactive Character Animation},

author = {Ari Shapiro and Frédéric Pighin},

url = {http://ict.usc.edu/pubs/Hybrid%20Control%20For%20Interactive%20Character%20Animation.pdf},

year  = {2003},

date = {2003-01-01},

booktitle = {Proceedings of the 11th Pacific Conference on Computer Graphics and Applications},

abstract = {We implement a framework for animating interactive characters by combining kinematic animation with physical simulation. The combination of animation techniques allows the characters to exploit the advantages of each technique. For example, characters can perform natural-looking kinematic gaits and react dynamically to unexpected situations.Kinematic techniques such as those based on motion capture data can create very natural-looking animation. However, motion capture based techniques are not suitable for modeling the complex interactions between dynamically interacting characters. Physical simulation, on the other hand, is well suited for such tasks. Our work develops kinematic and dynamic controllers and transition methods between the two control methods for interactive character animation. In addition, we utilize the motion graph technique to develop complex kinematic animation from shorter motion clips as a method of kinematic control.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{morie_gestalt_2003,

title = {The Gestalt of Virtual Environments},

author = {Jacquelyn Morie and Josh Williams},

url = {http://ict.usc.edu/pubs/The%20Gestalt%20of%20Virtual%20Environments.pdf},

year  = {2003},

date = {2003-01-01},

booktitle = {International Workshop on Presence},

abstract = {The majority of research in the field of virtual reality to date has focused on increasing the fidelity of the environments created and trying to determine the quality of the participant experience. Efforts have been made to quantify such aspects, especially in regards to visuals and sound, and to a lesser extent to the user experience. Recent thinking has tended towards the assumption that ever-greater fidelity would ensure a better user experience. However, such emphasis on photo-realism and audio-realism does not take into account the collective results of our multimodal sensory inputs with their intertwined effects. Our design philosophy for the creation of virtual environments attempts to replicate the human experience, and asks the question: Is there an underlying fidelity of feels-real through which the quality of the participant experience could be improved?},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{traum_negotiation_2003,

title = {Negotiation over Tasks in Hybrid Human-Agent Teams for Simulation-Based Training},

author = {David Traum and Jeff Rickel and Jonathan Gratch and Stacy C. Marsella},

url = {http://ict.usc.edu/pubs/Negotiation%20over%20Tasks%20in%20Hybrid%20Human-Agent%20Teams%20for%20Simulation-Based%20Training.pdf},

year  = {2003},

date = {2003-01-01},

booktitle = {International Conference on Autonomous Agents and Multiagent Systems (AAMAS)},

pages = {441–448},

address = {Melbourne, Australia},

abstract = {The effectiveness of simulation-based training for individual tasks – such as piloting skills – is well established, but its use for team training raises challenging technical issues. Ideally, human users could gain valuable leadership experience by interacting with synthetic teammates in realistic and potentially stressful scenarios. However, creating human-like teammates that can support flexible, natural interactions with humans and other synthetic agents requires integrating a wide variety of capabilities, including models of teamwork, models of human negotiation, and the ability to participate in face-to-face spoken conversations in virtual worlds. We have developed such virtual humans by integrating and extending prior work in these areas, and we have applied our virtual humans to an example peacekeeping training scenario to guide and evaluate our research. Our models allow agents to reason about authority and responsibility for individual actions in a team task and, as appropriate, to carry out actions, give and accept orders, monitor task execution, and negotiate options. Negotiation is guided by the agents' dynamic assessment of alternative actions given the current scenario conditions, with the aim of guiding the human user towards an ability to make similar assessments.},

keywords = {Social Simulation, Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{martinovski_error_2003,

title = {The Error Is the Clue: Breakdown In Human-Machine Interaction},

author = {Bilyana Martinovski and David Traum},

url = {http://ict.usc.edu/pubs/The%20Error%20Is%20the%20Clue-%20Breakdown%20In%20Human-Machine%20Interaction.pdf},

year  = {2003},

date = {2003-01-01},

booktitle = {Proceedings of ISCA Tutorial and Research Workshop International Speech Communication Association},

address = {Switzerland},

abstract = {This paper focuses not on the detection and correction of specific errors in the interaction between machines and humans, but rather cases of massive deviation from the user's conversational expectations and desires. This can be the result of too many or too unusual errors, but also from dialogue strategies disigned to minimize error, which make the interaction unnatutal in other ways. We study causes of irritation such as over-fragmentation, over-clarity, over-coordination, over-directedness, and repetiveness of verbal action, syntax, and intonation. Human reations to these irritating features typically appear in the following order: tiredness, tolerance, anger, confusion, irony, humor, exhaustion, uncertainty, lack of desire to communicate. The studied features of human expressions of irritation in non-face-to-face interaction are: intonation, emphatic speech, elliptic speech, speed of speech, extra-linguistic signs, speed of verbal action, and overlap.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{unger_capturing_2003,

title = {Capturing and Rendering With Incident Light Fields},

author = {J. Unger and Andreas Wenger and Tim Hawkins and Andrew Gardner and Paul Debevec},

url = {http://ict.usc.edu/pubs/Capturing%20and%20Rendering%20With%20Incident%20Light%20Fields.pdf},

year  = {2003},

date = {2003-01-01},

booktitle = {Proceedings of the 14th Eurographics workshop on Rendering},

abstract = {This paper presents a process for capturing spatially and directionally varying illumination from a real-world scene and using this lighting to illuminate computer-generated objects. We use two devices for capturing such illumination. In the first we photograph an array of mirrored spheres in high dynamic range to capture the spatially varying illumination. In the second, we obtain higher resolution data by capturing images with an high dynamic range omnidirectional camera as it traverses across a plane. For both methods we apply the light field technique to extrapolate the incident illumination to a volume. We render computer-generated objects as illuminated by this captured illumination using a custom shader within an existing global illumination rendering system. To demonstrate our technique we capture several spatially-varying lighting environments with spotlights, shadows, and dappled lighting and use them to illuminate synthetic scenes. We also show comparisons to real objects under the same illumination.},

keywords = {Graphics},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{bharitkar_robustness_2002-1,

title = {Robustness of Spatial Averaging Equalization Methods: A Statistical Approach},

author = {Sunil Bharitkar and Chris Kyriakakis},

url = {http://ict.usc.edu/pubs/Robustness%20of%20Spatial%20Averaging%20Equalization%20Methods-%20A%20Statistical%20Approach.pdf},

year  = {2002},

date = {2002-11-01},

booktitle = {IEEE 36th Asilomar Conference on Signals, Systems & Computers},

address = {Pacific Grove, CA},

abstract = {Traditionally, room response equalization is performed to improve sound quality at a given listener. However, room responses vary with source and listener positions. Hence, in a multiple listener environment, equalization may be performed through spatial averaging of room responses. However, the performance of averaging based equalization, at the listeners, may be affected when listener positions change. In this paper, we present a statistical approach to map variations in listener positions to performance of spatial averaging based equalization. The results indicate that, for the analyzed listener configurations, the zone of equalization depends on distance of microphones from a source and the frequencies in the sound.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{bharitkar_perceptual_2002,

title = {Perceptual Multiple Location Equalization with Clustering},

author = {Sunil Bharitkar and Chris Kyriakakis},

url = {http://ict.usc.edu/pubs/Perceptual%20Multiple%20Location%20Equalization%20with%20Clustering.pdf},

year  = {2002},

date = {2002-11-01},

booktitle = {IEEE 36th Asilomar Conference on Signals, Systems & Computers},

address = {Pacific Grove, CA},

abstract = {Typically, room equalization techniques do not focus on designing filters that equalize the room transfer functions on perceptually relevant spectral features. In this paper we address the problem of room equalization for multiple listeners, simultaneously, using a perceptually designed equalization filter based on pattern recognition techniques. Some features of the proposed filter are, its ability to perform simultaneous equalization at multiple locations, a reduced order, and a psychoacoustically motivated design. In summary, the simultaneous multiple location equalization, using a pattern recognition method, is performed over perceptually relevant spectral components derived from the auditory filtering mechanism.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{bharitkar_robustness_2002,

title = {Robustness of Multiple Listener Equalization With Magnitude Response Averaging},

author = {Sunil Bharitkar and Philip Hilmes and Chris Kyriakakis},

url = {http://ict.usc.edu/pubs/Robustness%20of%20Multiple%20Listener%20Equalization%20With%20Magnitude%20Response%20Averaging.pdf},

year  = {2002},

date = {2002-10-01},

booktitle = {Proceedings of the Audio Engineering Society Convention},

address = {Los Angeles, CA},

abstract = {Traditionally, room response equalization is performed to improve sound quality at a given listener. However, room responses vary with source and listener positions. Hence, in a multiple listener environment, equalization may be performed through spatial averaging of magnitude responses at locations of interest. However, the performance of averaging based equalization, at the listeners, may be a!ected when listener positions change. In this paper, we present a statistical approach to map variations in listener positions to a performance metric of equalization for magnitude response averaging. The results indicate that, for the analyzed listener configurations, the zone of equalization depends on distance of microphones from a source and the frequencies in the sound.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{georgiou_alternative_2002,

title = {An Alternative Model for Sound Signals Encountered in Reverberant Environments; Robust Maximum Likelihood Localization and Parameter Estimation Based on a Sub-Gaussian Model},

author = {Panayiotis G. Georgiou and Chris Kyriakakis},

url = {http://ict.usc.edu/pubs/An%20Alternative%20Model%20for%20Sound%20Signals%20Encountered%20in%20Reverberant%20Environments%3b%20Robust%20Maximum%20Likelihood%20Localization%20and%20Parameter%20Estimation%20Based%20on%20a%20Sub-Gaussian%20Model.pdf},

year  = {2002},

date = {2002-10-01},

booktitle = {Proceedings of the Audio Engineering Society Convention},

address = {Los Angeles, CA},

abstract = {In this paper we investigate an alternative to the Gaussian density for modeling signals encountered in audio environments. The observation that sound signals are impulsive in nature, combined with the reverberation e!ects commonly encountered in audio, motivates the use of the Sub-Gaussian density. The new Sub-Gaussian statistical model and the separable solution of its Maximum Likelihood estimator are derived. These are used in an array scenario to demonstrate with both simulations and two different microphone arrays the achievable performance gains. The simulations exhibit the robustness of the sub-Gaussian based method while the real world experiments reveal a significant performance gain, supporting the claim that the sub-Gaussian model is better suited for sound signals.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{johnson_limited_2002,

title = {Limited Domain Synthesis of Expressive Military Speech for Animated Characters},

author = {W. Lewis Johnson and Shrikanth Narayanan and Richard Whitney and Rajat Das and Catherine Labore},

url = {http://ict.usc.edu/pubs/Limited%20Domain%20Synthesis%20of%20Expressive%20Military%20Speech%20for%20Animated%20Characters.pdf},

year  = {2002},

date = {2002-09-01},

booktitle = {IEEE 2002 Workshop on Speech Synthesis},

abstract = {Text-to-speech synthesis can play an important role in interactive education and training applications, as voices for animated agents. Such agents need high-quality voices capable of expressing intent and emotion. This paper presents preliminary results in an effort aimed at synthesizing expressive military speech for training applications. Such speech has acoustic and prosodic characteristics that can differ markedly from ordinary conversational speech. A limited domain synthesis approach is used employing samples of expressive speech, classified according to speaking style. The resulting synthesizer was tested both in isolation and in the context of a virtual reality training scenario with animated characters.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{gordon_theory_2002,

title = {The Theory of Mind in Strategy Representations},

author = {Andrew S. Gordon},

url = {http://ict.usc.edu/pubs/The%20Theory%20of%20Mind%20in%20Strategy%20Representations.PDF},

year  = {2002},

date = {2002-08-01},

booktitle = {Proceedings of the Twenty-fourth Annual Meeting of the Cognitive Science Society (CogSci)},

publisher = {Lawrence Erlbaum Associates},

address = {George Mason University},

abstract = {Many scientific fields continue to explore cognition related to Theory of Mind abilities, where people reason about the mental states of themselves and others. Experimental and theoretical approaches to this problem have largely avoided issues concerning the contents of representations employed in this class of reasoning. In this paper, we describe a new approach to the investigation of representations related to Theory of Mind abilities that is based on the analysis of commonsense strategies. We argue that because the mental representations of strategies must include concepts of mental states and processes, the large-scale analysis of strategies can be informative of the representational scope of Theory of Mind abilities. The results of an analysis of this sort are presented as a description of thirty representational areas that organize the breadth of Theory of Mind concepts. Implications for Theory Theories and Simulation Theories of Theory of Mind reasoning are discussed.},

keywords = {The Narrative Group},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{angros_learning_2002,

title = {Learning Domain Knowledge for Teaching Procedural Skills},

author = {Richard Jr. Angros and W. Lewis Johnson and Jeff Rickel and Andrew Scholer},

url = {http://ict.usc.edu/pubs/Learning%20Domain%20Knowledge%20for%20Teaching%20Procedural%20Skills.pdf},

year  = {2002},

date = {2002-07-01},

booktitle = {International Conference on Autonomous Agents and Multiagent Systems (AAMAS)},

address = {Bologna, Italy},

abstract = {This paper describes a method for acquiring procedural knowledge for use by pedagogical agents in interactive simulation-based learning environments. Such agents need to be able to adapt their behavior to the changing conditions of the simulated world, and respond appropriately in mixed-initiative interactions with learners. This requires a good understanding of the goals and causal dependencies in the procedures being taught. Our method, inspired by human tutorial dialog, combines direct specification, demonstration, and experimentation. The human instructor demonstrates the skill being taught, while the agent observes the effects of the procedure on the simulated world. The agent then autonomously experiments with the procedure, making modifications to it, in order to understand the role of each step in the procedure. At various points the instructor can provide clarifications, and modify the developing procedural description as needed. This method is realized in a system called Diligent, which acquires procedural knowledge for the STEVE animated pedagogical agent.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{traum_embodied_2002,

title = {Embodied Agents for Multi-party Dialogue in Immersive Virtual Worlds},

author = {David Traum and Jeff Rickel},

url = {http://ict.usc.edu/pubs/Embodied%20Agents%20for%20Multi-party%20Dialogue%20in%20Immersive%20%20Virtual%20Worlds.pdf},

year  = {2002},

date = {2002-07-01},

booktitle = {International Conference on Autonomous Agents and Multiagent Systems (AAMAS)},

address = {Bologna, Italy},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{kovar_motion_2002,

title = {Motion Graphs},

author = {Lucas Kovar and Michael Gleicher and Frédéric Pighin},

url = {http://ict.usc.edu/pubs/Motion%20Graphs.pdf},

year  = {2002},

date = {2002-07-01},

booktitle = {Proceedings of SIGGRAPH '02},

address = {San Antonio, TX},

abstract = {n this paper we present a novel method for creating realistic, controllable motion. Given a corpus of motion capture data, we automatically construct a directed graph called a motion graph that encapsulates connections among the database. The motion graph consists both of pieces of original motion and automatically generated transitions. Motion can be generated simply by building walks on the graph. We present a general framework for extracting particular graph walks that meet a user's specifications. We then show how this framework can be applied to the specific problem of generating different styles of locomotion along arbitrary paths.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{debevec_lighting_2002,

title = {A Lighting Reproduction Approach to Live-Action Compositing},

author = {Paul Debevec and Andreas Wenger and Chris Tchou and Andrew Gardner and Jamie Waese and Tim Hawkins},

url = {http://ict.usc.edu/pubs/A%20Lighting%20Reproduction%20Approach%20to%20Live-Action%20Compositing.pdf},

year  = {2002},

date = {2002-07-01},

booktitle = {SIGGRAPH 2002},

pages = {547–556},

address = {San Antonio, TX},

abstract = {We describe a process for compositing a live performance of an actor into a virtual set wherein the actor is consistently illuminated by the virtual environment. The Light Stage used in this work is a two-meter sphere of inward-pointing RGB light emitting diodes focused on the actor, where each light can be set to an arbitrary color and intensity to replicate a real-world or virtual lighting environment. We implement a digital two-camera infrared matting system to composite the actor into the background plate of the environment without affecting the visible-spectrum illumination on the actor. The color reponse of the system is calibrated to produce correct color renditions of the actor as illuminated by the environment. We demonstrate moving-camera composites of actors into real-world environments and virtual sets such that the actor is properly illuminated by the environment into which they are composited.},

keywords = {Graphics},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{marsella_modeling_2002,

title = {Modeling the Influence of Emotion on Belief for Virtual Training Simulations},

author = {Stacy C. Marsella and Jonathan Gratch},

url = {http://ict.usc.edu/pubs/Modeling%20the%20influence%20of%20emotion.pdf},

year  = {2002},

date = {2002-06-01},

booktitle = {Proceedings of the 11th Conference on Computer Generated Forces and Behavioral Simulation},

address = {Orlando, FL},

abstract = {Recognizing and managing emotion in oneself and in those under ones command is an important component of leadership training. Most computational models of emotion have focused on the problem of identifying emotional features of the physical environment and mapping that into motivations to act in the world. But emotions also influence how we perceive the world and how we communicate that perception to others. This paper outlines an initial computational foray into this more vexing problem.},

keywords = {Social Simulation, Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{gordon_virtual_2002,

title = {Virtual Humans as Participants vs. Virtual Humans as Actors},

author = {Andrew S. Gordon and Michael Lent},

url = {http://ict.usc.edu/pubs/Virtual%20Humans%20as%20Participants%20vs%20Virtual%20Humans%20as%20Actors.PDF},

year  = {2002},

date = {2002-03-01},

booktitle = {AAAI Spring Symposium on Artificial Intelligence and Interactive Entertainment},

address = {Stanford University},

keywords = {The Narrative Group},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{gordon_enabling_2002,

title = {Enabling and recognizing strategic play in strategy games: Lessons from Sun Tzu},

author = {Andrew S. Gordon},

url = {http://ict.usc.edu/pubs/Enabling%20and%20recognizing%20strategic%20play%20in%20strategy%20games-%20Lessons%20from%20Sun%20Tzu.PDF},

year  = {2002},

date = {2002-03-01},

booktitle = {The 2002 AAAI Spring Symposium on Artificial Intelligence and Interactive Entertainment},

address = {Stanford University},

abstract = {The interactive entertainment genre of the strategy game entertains users by allowing them to engage in strategic play, which should encourage game designers to devote development efforts toward facilitating users that wish to employ commonsense strategies, and to recognize and react to specific user strategies during game play. This paper attempts to facilitate these development efforts by identifying and analyzing 43 strategies from Sun Tzu's The Art of War, which are broadly applicable across games in the strategy game genre. For each strategy, a set of specific actions are identified that should be provided to users to enable their execution, along with generalized recognition rules that can facilitatethe design of entertaining responses to users' strategic behavior. Consideration of how the enabling actions could be incorporated into an existing strategy game is provided.},

keywords = {The Narrative Group},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{fleischman_emotional_2002,

title = {Emotional Variation in Speech-Based Natural Language Generation},

author = {Michael Fleischman and Eduard Hovy},

url = {http://ict.usc.edu/pubs/Emotional%20Variation%20in%20Speech-Based%20Natural%20Language%20Generation.pdf},

year  = {2002},

date = {2002-01-01},

booktitle = {International Natural Language Generation Conference},

abstract = {We present a framework for handling emotional variations in a speech-based natural language system for use in the MRE virtual training environment. The system is a first step toward addressing issues in emotion-based modeling of verbal communicative behavior. We cast the problem of emotional generation as a distance minimization task, in which the system chooses between multiple valid realizations for a given input based on the emotional distance of each realization from the speaker's attitude toward that input.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{hill_applying_2002,

title = {Applying Perceptually Driven Cognitive Mapping To Virtual Urban Environments},

author = {Randall W. Hill and Changhee Han and Michael Lent},

url = {http://ict.usc.edu/pubs/Applying%20Perceptually%20Driven%20Cognitive%20Mapping%20To%20Virtual%20Urban%20Environments.pdf},

year  = {2002},

date = {2002-01-01},

booktitle = {Proceedings of 14th Innovative Applications of Artificial Intelligence Conference},

abstract = {This paper describes a method for building a cognitive map of a virtual urban environment. Our routines enable virtual humans to map their environment using a realistic model of perception. We based our implementation on a computational framework proposed by Yeap and Jefferies (Yeap & Jefferies 1999) for representing a local environment as a structure called an Absolute Space Representation (ASR). Their algorithms compute and update ASRs from a 2-1/2D 1 sketch of the local environment, and then connect the ASRs together to form a raw cognitive map. Our work extends the framework developed by Yeap and Jefferies in three important ways. First, we implemented the framework in a virtual training environment, the Mission Rehearsal Exercise (Swartout et al. 2001). Second, we describe a method for acquiring a 2- 1/2D sketch in a virtual world, a step omitted from their framework, but which is essential for computing an ASR. Third, we extend the ASR algorithm to map regions that are partially visible through exits of the local space. Together, the implementation of the ASR algorithm along with our extensions will be useful in a wide variety of applications involving virtual humans and agents who need to perceive and reason about spatial concepts in urban environments.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{traum_ideas_2002,

title = {Ideas on Multi-layer Dialogue Management for Multi-party, Multi-conversation, Multi-modal Communication},

author = {David Traum},

url = {http://ict.usc.edu/pubs/Ideas%20on%20Multi-layer%20Dialogue%20Management%20for%20Multi-party,%20Multi-conversation,%20Multi-modal%20Communication.pdf},

year  = {2002},

date = {2002-01-01},

booktitle = {Computational Linguistics in the Netherlands 2001: Selected Papers from the Twelth CLIN Meeting},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{marsella_step_2002,

title = {A step toward irrationality: using emotion to change belief},

author = {Stacy C. Marsella and Jonathan Gratch},

url = {http://ict.usc.edu/pubs/A%20step%20toward%20irrationality-%20using%20emotion%20to%20change%20belief.pdf},

year  = {2002},

date = {2002-01-01},

booktitle = {International Conference on Autonomous Agents and Multiagent Systems (AAMAS)},

volume = {1},

pages = {334–341},

address = {Bologna, Italy},

abstract = {Emotions have a powerful impact on behavior and beliefs. The goal of our research is to create general computational models of this interplay of emotion, cognition and behavior to inform the design of virtual humans. Here, we address an aspect of emotional behavior that has been studied extensively in the psychological literature but largely ignored by computational approaches, emotion-focused coping. Rather than motivating external action, emotion-focused coping strategies alter beliefs in response to strong emotions. For example an individual may alter beliefs about the importance of a goal that is being threatened, thereby reducing their distress. We present a preliminary model of emotion-focused coping and discuss how coping processes, in general, can be coupled to emotions and behavior. The approach is illustrated within a virtual reality training environment where the models are used to create virtual human characters in high-stress social situations.},

keywords = {Social Simulation, Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{hill_anticipating_2002,

title = {Anticipating where to look: predicting the movements of mobile agents in complex terrain},

author = {Randall W. Hill and Youngjun Kim and Jonathan Gratch},

url = {http://ict.usc.edu/pubs/Anticipating%20Where%20to%20Look-%20Predicting%20the%20Movements%20of%20Mobile%20Agents%20in%20Complex%20Terrain.pdf},

year  = {2002},

date = {2002-01-01},

booktitle = {International Conference on Autonomous Agents and Multiagent Systems (AAMAS)},

volume = {2},

pages = {821–827},

address = {Bologna, Italy},

abstract = {This paper describes a method for making short-term predictions about the movement of mobile agents in complex terrain. Virtual humans need this ability in order to shift their visual attention between dynamic objects-predicting where an object will be located a few seconds in the future facilitates the visual reacquisition of the target object. Our method takes into account environmental cues in making predictions and it also indicates how long the prediction is valid, which varies depending on the context. We implemented this prediction technique in a virtual pilot that flies a helicopter in a synthetic environment.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{morie_emotionally_2002,

title = {Emotionally Evocative Environments for Training},

author = {Jacquelyn Morie and Kumar Iyer and R. Valanejad and Ramy Sadek and D. Miraglia and D. Milam},

url = {http://ict.usc.edu/pubs/EMOTIONALLY%20EVOCATIVE%20ENVIRONMENTS%20FOR%20TRAINING.pdf},

year  = {2002},

date = {2002-01-01},

booktitle = {Proceedings of the 23th Army Science Conference},

address = {Orlando, FL},

abstract = {This paper describes a project currently in progress at the University of Southern California's Institute for Creative Technologies (ICT). Much of the research at ICT involves developing better graphics, sound and artificial intelligence to be used in creating the next generation of training tools for the United States Army. Our project focuses on the use of emotional responses as an enhancement for training. Research indicates that an emotional connection is a strong factor in how and what we remember. In addition, real world situations often evoke surprising and significant emotional reactions that soldiers must deal with. Few current immersive training scenarios, however, focus on the emotional state of the trainee, limiting training scenarios to basic objective elements. The Sensory Environments Evaluation (SEE) Project at ICT is investigating the potential of emotionally compelling environments for more effective training. We do this by skillfully combining the sensory inputs available in virtual environments. Our current efforts concentrate on sight and sound; smell will be included as scent delivery methods improve. Evaluation studies are planned to determine the effectiveness of the techniques we are developing.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{bharitkar_robustness_2001,

title = {Robustness of the Eigenfilter for Variations in Listener Responses for Selective Signal Cancellation},

author = {Sunil Bharitkar and Chris Kyriakakis},

url = {http://ict.usc.edu/pubs/ROBUSTNESS%20OF%20THE%20EIGENFILTER%20FOR%20VARIATIONS%20IN%20LISTENER%20RESPONSES%20FOR%20SELECTIVE%20SIGNAL%20CANCELLATION.pdf},

year  = {2001},

date = {2001-10-01},

booktitle = {IEEE Workshop on Applications of Signal Processing to Audio and Acoustics},

address = {New Paltz, New York},

abstract = {Selectively cancelling signals at specific locations within an acoustical environment with multiple listeners is of significant importance for home theater, automobile, teleconferencing, office, industrial and other applications. We have proposed the eigenfilter for selectively cancelling signals in one direction, while attempting to retain them at unintentional directions. In this paper we investigate the behaviour of the performance measure (i.e., the gain) for a vowel and an unvoiced fricative, when the listener moves his head, in an automobile type environment. We show that in such a situation, a large energy in the difference between the impulse responses at a listener's location may affect the gain substantially. listeners in which only a subset wish to listen to the audio signal.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{gratch_adaptive_2001,

title = {Adaptive narrative: How autonomous agents, hollywood, and multiprocessing operating systems can live happily ever after},

author = {Jonathan Gratch and Jay Douglas},

url = {http://ict.usc.edu/pubs/Adaptive%20Narrative-%20How%20Autonomous%20Agents,%20Hollywood,%20and%20Multiprocessing%20Operating%20Systems%20Can%20Live%20Happily%20Ever%20After.pdf},

doi = {10.1007/3-540-45420-9_12},

isbn = {3-540-42611-6},

year  = {2001},

date = {2001-10-01},

booktitle = {Proceedings of International Conference on Virtual Storytelling},

pages = {100–112},

address = {Avignon, France},

series = {LNCS},

abstract = {Interacting Storytelling systems integrate AI techniques such as planning with narrative representations to generate stories. In this paper, we discuss the use of planning formalisms in Interactive Storytelling from the perspective of story generation and authoring. We compare two different planning formalisms, Hierarchical Task Network (HTN) planning and Heuristic Search Planning (HSP). While HTN provide a strong basis for narrative coherence in the context of interactivity, HSP offer additional flexibility and the generation of stories and the mechanisms for generating comic situations.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{rickel_intelligent_2001,

title = {Intelligent Virtual Agents for Education and Training: Opportunities and Challenges},

author = {Jeff Rickel},

url = {http://ict.usc.edu/pubs/Intelligent%20Virtual%20Agents%20for%20Education%20and%20Training-%20Opportunities%20and%20Challenges.pdf},

year  = {2001},

date = {2001-09-01},

booktitle = {Intelligent Virtual Agents: The 3rd International Workshop},

address = {Madrid, Spain},

abstract = {Interactive virtual worlds provide a powerful medium for ex- periential learning. Intelligent virtual agents can cohabit virtual worlds with people and facilitate such learning as guides, mentors, and team- mates. This paper reviews the main pedagogical advantages of animated agents in virtual worlds, discusses two key research challenges, and out- lines an ambitious new project addressing those challenges.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{bharitkar_new_2001,

title = {New Factors in Room Equalization Using a Fuzzy Logic Approach},

author = {Sunil Bharitkar and Chris Kyriakakis},

url = {http://ict.usc.edu/pubs/New%20Factors%20in%20Room%20Equalization%20Using%20a%20Fuzzy%20Logic%20Approach.pdf},

year  = {2001},

date = {2001-09-01},

booktitle = {Proceedings of the Audio Engineering Society Convention},

address = {New York, NY},

abstract = {Room acoustical modes, particularly in small rooms, cause a significant variation in the room responses measured at di!erent locations. Responses measured only a few cm apart can vary by up to 15-20 dB at certain frequencies. This makes it diffcult to equalize an audio system for multiple simultaneous listeners. Previous methods have utilized multiple microphones and spatial averaging with equal weighting. In this paper we present a different multiple point equalization method. We first determine representative prototypical room responses derived from several room responses that share similar characteristics, using the fuzzy unsupervised learning method. These prototypical responses can then be combined to form a general point response. When we use the inverse of the general point response as an equalizing filter, our results show a significant improvement in equalization performance over the spatial averaging methods. This simultaneous equalization is achieved by suppressing the peaks in the room magnitude spectrums. Applications of this method thus include equalization and multiple point sound control at home and in automobiles.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{marsella_effect_2001,

title = {The Effect of Affect: Modeling the Impact of Emotional State on the Behavior of Interactive Virtual Humans},

author = {Stacy C. Marsella and Jonathan Gratch and Jeff Rickel},

url = {http://ict.usc.edu/pubs/The%20Effect%20of%20Affect-%20Modeling%20the%20Impact%20of%20Emotional%20State%20on%20the%20Behavior%20of%20Interactive%20Virtual%20Humans.pdf},

year  = {2001},

date = {2001-06-01},

booktitle = {Workshop on Representing, Annotating, and Evaluating Non-Verbal and Verbal Communicative Acts to Achieve Contextual Embodied Agents},

address = {Montreal, Canada},

abstract = {A person's behavior provides significant information about their emotional state, attitudes, and attention. Our goal is to create virtual humans that convey such information to people while interacting with them in virtual worlds. The virtual humans must respond dynamically to the events surrounding them, which are fundamentally influenced by users' actions, while providing an illusion of human-like behavior. A user must be able to interpret the dynamic cognitive and emotional state of the virtual humans using the same nonverbal cues that people use to understand one another. Towards these goals, we are integrating and extending components from three prior systems: a virtual human architecture with a range of cognitive and motor capabilities, a model of emotional appraisal, and a model of the impact of emotional state on physical behavior. We describe the key research issues, our approach, and an initial implementation in an Army peacekeeping scenario.},

keywords = {Social Simulation, Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{douglas_adaptive_2001,

title = {Adaptive Narrative: How Autonomous Agents, Hollywood, and Multiprocessing Operating Systems Can Live Happily Ever After},

author = {Jay Douglas and Jonathan Gratch},

url = {http://ict.usc.edu/pubs/Adaptive%20Narrative-%20How%20Autonomous%20Agents,%20Hollywood,%20and%20Multiprocessing%20Operating%20Systems%20Can%20Live%20Happily%20Ever%20After.pdf},

year  = {2001},

date = {2001-06-01},

booktitle = {Proceedings of the 5th International Conference on Autonomous Agents},

address = {Montreal, Canada},

abstract = {Creating dramatic narratives for real-time virtual reality environments is complicated by the lack of temporal distance between the occurrence of an event and its telling in the narrative. This paper describes the application of a multiprocessing operating system architecture to the creation of adaptive narratives, narratives that use autonomous actors or agents to create real-time dramatic experiences for human interactors. We also introduce the notion of dramatic acts and dramatic functions and indicate their use in constructing this real-time drama.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{cohen_real-time_2001,

title = {Real-Time High-Dynamic Range Texture Mapping},

author = {Jonathan Cohen and Chris Tchou and Tim Hawkins and Paul Debevec},

url = {http://ict.usc.edu/pubs/Real-Time%20High-Dynamic%20Range%20Texture%20Mapping.pdf},

year  = {2001},

date = {2001-06-01},

booktitle = {Eurographics Rendering Workshop},

abstract = {This paper presents a technique for representing and displaying high dynamic-range texture maps (HDRTMs) using current graphics hardware. Dynamic range in real-world environments often far exceeds the range representable in 8-bit per-channel texture maps. The increased realism afforded by a high-dynamic range representation provides improved fidelity and expressiveness for interactive visualization of image-based models. Our technique allows for real-time rendering of scenes with arbitrary dynamic range, limited only by available texture memory. In our technique, high-dynamic range textures are decomposed into sets of 8- bit textures. These 8-bit textures are dynamically reassembled by the graphics hardware's programmable multitexturing system or using multipass techniques and framebuffer image processing. These operations allow the exposure level of the texture to be adjusted continuously and arbitrarily at the time of rendering, correctly accounting for the gamma curve and dynamic range restrictions of the display device. Further, for any given exposure only two 8-bit textures must be resident in texture memory simultaneously. We present implementation details of this technique on various 3D graphics hardware architectures. We demonstrate several applications, including high-dynamic range panoramic viewing with simulated auto-exposure, real-time radiance environment mapping, and simulated Fresnel reflection.},

keywords = {Graphics},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{swartout_toward_2001,

title = {Toward the Holodeck: Integrating Graphics, Sound, Character and Story},

author = {William Swartout and Randall W. Hill and Jonathan Gratch and W. Lewis Johnson and Chris Kyriakakis and Catherine Labore and Richard Lindheim and Stacy C. Marsella and D. Miraglia and Bridget Moore and Jacquelyn Morie and Jeff Rickel and Marcus Thiebaux and L. Tuch and Richard Whitney and Jay Douglas},

url = {http://ict.usc.edu/pubs/Toward%20the%20Holodeck-%20Integrating%20Graphics,%20Sound,%20Character%20and%20Story.pdf},

year  = {2001},

date = {2001-06-01},

booktitle = {Proceedings of the 5th International Conference on Autonomous Agents},

address = {Montreal, Canada},

abstract = {We describe an initial prototype of a holodeck-like environment that we have created for the Mission Rehearsal Exercise Project. The goal of the project is to create an experience learning system where the participants are immersed in an environment where they can encounter the sights, sounds, and circumstances of realworld scenarios. Virtual humans act as characters and coaches in an interactive story with pedagogical goals.},

keywords = {Social Simulation, Virtual Humans, Virtual Worlds},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{gratch_modeling_2001,

title = {Modeling Emotions in the Mission Rehearsal Exercise},

author = {Jonathan Gratch and Stacy C. Marsella},

url = {http://ict.usc.edu/pubs/Modeling%20Emotions%20in%20the%20Mission%20Rehearsal%20Exercise.pdf},

year  = {2001},

date = {2001-05-01},

booktitle = {Proceedings of the 10th Conference on Computer Generated Forces and Behavioral Representation},

pages = {457–466},

address = {Orlando, FL},

abstract = {This paper discusses our attempts to model realistic human behavior in the context of the Mission Rehearsal Exercise system (MRE), a high-end virtual training environment designed to support dismounted infantry training between a human participant and elements of his command. The system combines immersive graphics, sound, and interactive characters controlled by artificial intelligence programs. Our goal in this paper is to show how some of the daunting subtlety in human behavior can be modeled by intelligent agents and in particular to focus on the role of modeling typical human emotional responses to environmental stimuli.},

keywords = {Social Simulation, Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{ligorio_interlocution_2001,

title = {Interlocution Scenarios for Problem Solving in an Educational MUD Environment},

author = {M. Beatrice Ligorio and Giuseppe Mininni and David Traum},

url = {http://ict.usc.edu/pubs/INTERLOCUTION%20SCENARIOS%20FOR%20PROBLEM%20SOLVING%20IN%20AN%20EDUCATIONAL%20MUD%20ENVIRONMENT.pdf},

year  = {2001},

date = {2001-03-01},

booktitle = {1st European Conference on Computer-Supported Collaborative Learning},

abstract = {This paper presents an analysis of computer mediated collaboration on a problem-solving task in a virtual world. The theoretical framework of this research combines research in Computer Mediated Communication with a social psychology theory of conflict. An experiment was conducted involving universitybstudents performing a problem solving task with a peer in an Educational MUD. Each performance was guided by a predefined script, designed based on the 'common speech' concepts. Al the performances were analyzed in terms of identity perception, conflict perception and cooperation. By looking at the relationship among the CMC environment features, the social influence activated on this environment, the conflict elaboration, and the problem solving strategies, a distinctive 'interlocution scenario' emerged. The results are discussed using contributions from the two theoretical approaches embraced.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}