Publications

@inproceedings{fyffe_cosine_2009,

title = {Cosine Lobe Based Relighting from Gradient Illumination Photographs},

author = {Graham Fyffe and Cyrus A. Wilson and Paul Debevec},

url = {http://www.ict.usc.edu/pubs/Cosine%20Lobe%20Based%20Relighting%20from%20Gradient%20Illumination%20Photographs.pdf},

year  = {2009},

date = {2009-11-01},

booktitle = {Conference on Visual Media Production},

address = {London, UK},

abstract = {We present an image-based method for relighting a scene by analytically fitting a cosine lobe to the reflectance function at each pixel, based on gradient illumination pho- tographs. Realistic relighting results for many materials are obtained using a single per-pixel cosine lobe obtained from just two color photographs: one under uniform white illumi- nation and the other under colored gradient illumination. For materials with wavelength-dependent scattering, a better fit can be obtained using independent cosine lobes for the red, green, and blue channels, obtained from three monochromatic gradient illumination conditions instead of the colored gradient condition. We explore two cosine lobe reflectance functions, both of which allow an analytic fit to the gradient conditions. One is non-zero over half the sphere of lighting directions, which works well for diffuse and specular materials, but fails for materials with broader scattering such as fur. The other is non-zero everywhere, which works well for broadly scattering materials and still produces visually plausible results for diffuse and specular materials. Additionally, we estimate scene geometry from the photometric normals to produce hard shadows cast by the geometry, while still reconstructing the input photographs exactly.},

keywords = {Graphics},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{alexander_creating_2009,

title = {Creating a Photoreal Digital Actor: The Digital Emily Project},

author = {Oleg Alexander and Mike Rogers and William Lambeth and Matt Chiang and Paul Debevec},

url = {https://dl.acm.org/doi/pdf/10.1145/1667239.1667251},

year  = {2009},

date = {2009-11-01},

booktitle = {IEEE European Conference on Visual Media Production (CVMP)},

number = {ICT TR 04 2009},

address = {London, UK},

institution = {University of Southern California Institute for Creative Technologies},

abstract = {The Digital Emily Project is a collaboration between facial animation company Image Metrics and the Graphics Laboratory at the University of Southern California's Institute for Creative Technologies to achieve one of the world's first photorealistic digital facial performances. The project leverages latest-generation techniques in high-resolution face scanning, character rigging, video-based facial animation, and compositing. An actress was first filmed on a studio set speaking emotive lines of dialog in high definition. The lighting on the set was captured as a high dynamic range light probe image. The actress' face was then three-dimensionally scanned in thirty-three facial expressions showing different emotions and mouth and eye movements using a high-resolution facial scanning process accurate to the level of skin pores and fine wrinkles. Lighting-independent diffuse and specular reflectance maps were also acquired as part of the scanning process. Correspondences between the 3D expression scans were formed using a semi-automatic process, allowing a blendshape facial animation rig to be constructed whose expressions closely mirrored the shapes observed in the rich set of facial scans; animated eyes and teeth were also added to the model. Skin texture detail showing dynamic wrinkling was converted into multiresolution displacement maps also driven by the blend shapes. A semi-automatic video-based facial animation system was then used to animate the 3D face rig to match the performance seen in the original video, and this performance was tracked onto the facial motion in the studio video. The final face was illuminated by the captured studio illumination and shading using the acquired reflectance maps with a skin translucency shading algorithm. Using this process, the project was able to render a synthetic facial performance which was generally accepted as being a real face.},

keywords = {Graphics},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{von_der_puitten_who_2009,

title = {Who Is there? Can a Virtual Agent Really Elicit Social Presence?},

author = {Astrid M. Pütten and Nicole Krämer and Jonathan Gratch},

url = {http://ict.usc.edu/pubs/whosthere.pdf},

year  = {2009},

date = {2009-11-01},

booktitle = {The 12th Annual International Workshop on Presence},

address = {Los Angeles, CA},

abstract = {This study investigates whether humans perceive a higher degree of social presence when interacting with an animated character that displays natural as opposed to no listening behaviors and whether this interacts with people's believe that they are interacting with an agent or an avatar. In a 2x2 between subjects experimental design 83 participants were either made believe that they encounter an agent, or that they communicate with another participant mediated by an avatar. In fact, in both conditions the communication partner was an autonomous agent that either exhibited high or low behavioral realism. We found that participants experienced equal amounts of presence, regardless of interacting with an agent or an avatar. Behavioral realism, however, had an impact on the subjective feeling of presence: people confronted with a character displaying high behavioral realism reported a higher degree of mutual awareness.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{rosenbloom_towards_2009-1,

title = {Towards Uniform Implementation of Architectural Diversity},

author = {Paul S. Rosenbloom},

url = {http://ict.usc.edu/pubs/Towards%20Uniform%20Implementation%20of%20Architectural%20Diversity.pdf},

year  = {2009},

date = {2009-11-01},

booktitle = {Proceedings of the AAAI Fall Symposium on Multi-Representational Architectures for Human-Level Intelligence},

abstract = {Multi-representational architectures exploit diversity to yield the breadth of capabilities required for intelligent behavior in the world, but in so doing can sacrifice too much of the complementary benefits of architectural uniformity. The proposal here is to couple the benefits of diversity and uniformity through establishment of a uniform graph-based implementation level for diverse architectures.},

keywords = {CogArch, Cognitive Architecture, Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{han_signature_2009,

title = {Signature Cluster Model Selection for Incremental Gaussian Mixture Cluster Modeling in Agglomerative Hierarchical Speaker Clustering},

author = {Kyu J. Han and Shrikanth Narayanan},

url = {http://ict.usc.edu/pubs/Signature%20Cluster%20Model%20Selection.pdf},

year  = {2009},

date = {2009-10-01},

booktitle = {Proceedings of Interspeech 2009},

address = {Brighton, UK},

abstract = {Agglomerative hierarchical speaker clustering (AHSC) has been widely used for classifying speech data by speaker charac- teristics. Its bottom-up, one-way structure of merging the clos- est cluster pair at every recursion step, however, makes it diffi- cult to recover from incorrect merging. Hence, making AHSC robust to incorrect merging is an important issue. In this pa- per we address this problem in the framework of AHSC based on incremental Gaussian mixture models, which we previously introduced for better representing variable cluster size. Specif- ically, to minimize contamination in cluster models by hetero- geneous data, we select and keep updating a representative (or signature) model for each cluster during AHSC. Experiments on meeting speech excerpts (4 hours total) verify that the proposed approach improves average speaker clustering performance by approximately 20% (relative).},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{kalinli_saliency-driven_2009,

title = {Saliency-Driven Unstructured Acoustic Scene Classification Using Latent Perceptual Indexing},

author = {Ozlem Kalinli and Shiva Sundaram and Shrikanth Narayanan},

url = {http://ict.usc.edu/pubs/Saliency-Driven%20Unstructured%20Acoustic%20Scene%20Classification%20Using%20Latent%20Perceptual%20Indexing.pdf},

year  = {2009},

date = {2009-10-01},

booktitle = {Proceedings of IEEE MMSP},

address = {Rio de Janeiro, Brazil},

abstract = {Automatic acoustic scene classification of real life, complex and unstructured acoustic scenes is a challenging task as the number of acoustic sources present in the audio stream are unknown and overlapping in time. In this work, we present a novel approach to classification such unstructured acoustic scenes. Motivated by the bottom-up attention model of the human auditory system, salient events of an audio clip are extracted in an unsupervised manner and presented to the classification system. Similar to latent semantic indexing of text documents, the classi- fication system uses unit-document frequency measure to index the clip in a continuous, latent space. This allows for developing a completely class-independent approach to audio classification. Our results on the BBC sound effects library indicates that using the saliency-driven attention selection approach presented in this paper, 17.5% relative improvement can be obtained in frame-based classification and 25% relative improvement can be obtained using the latent audio indexing approach.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{kalinli_continuous_2009,

title = {Continuous Speech Recognition Using Attention Shift Decoding with Soft Decision},

author = {Ozlem Kalinli and Shrikanth Narayanan},

url = {http://ict.usc.edu/pubs/Continuous%20Speech%20Recognition%20Using%20Attention%20Shift%20Decoding%20with%20Soft%20Decision.pdf},

year  = {2009},

date = {2009-10-01},

booktitle = {Proceedings of Interspeech 2009},

address = {Brighton, UK},

abstract = {We present an attention shift decoding (ASD) method inspired by human speech recognition. In contrast to the traditional auto- matic speech recognition (ASR) systems, ASD decodes speech inconsecutively using reliability criteria; the gaps (unreliable speech regions) are decoded with the evidence of islands (reli- able speech regions). On the BU Radio News Corpus, ASD pro- vides significant improvement (2.9% absolute) over the baseline ASR results when it is used with oracle island-gap informa- tion. At the core of the ASD method is the automatic island- gap detection. Here, we propose a new feature set for automatic island-gap detection which achieves 83.7% accuracy. To cope with the imperfect nature of the island-gap classification, we also propose a new ASD algorithm using soft decision. The ASD with soft decision provides 0.4% absolute (2.2% relative) improvement over the baseline ASR results when it is used with automatically detected islands and gaps.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{lee_learning_2009-1,

title = {Learning a Model of Speaker Head Nods using Gesture Corpora},

author = {Jina Lee and Stacy C. Marsella and Helmut Prendinger and Alena Neviarouskaya},

url = {http://ict.usc.edu/pubs/learning%20a%20model%20of%20speaker%20head%20nods.pdf},

year  = {2009},

date = {2009-10-01},

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

address = {Budapest, Hungary},

abstract = {During face-to-face conversation, the speaker's head is continually in motion. These movements serve a variety of important communicative functions, and may also be influ- enced by our emotions. The goal for this work is to build a domain-independent model of speaker's head movements and investigate the effect of using affective information dur- ing the learning process. Once the model is learned, it can later be used to generate head movements for virtual agents. In this paper, we describe our machine-learning approach to predict speaker's head nods using an annotated corpora of face-to-face human interaction and emotion labels gener- ated by an affect recognition model. We describe the feature selection process, training process, and the comparison of results of the learned models under varying conditions. The results show that using affective information can help pre- dict head nods better than when no affective information is used.},

keywords = {Social Simulation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{sagae_analysis_2009,

title = {Analysis of Discourse Structure with Syntactic Dependencies and Data-Driven Shift-Reduce Parsing},

author = {Kenji Sagae},

url = {http://ict.usc.edu/pubs/Analysis%20of%20discourse%20structure.pdf},

year  = {2009},

date = {2009-10-01},

booktitle = {International Conference on Parsing Technologies (IWPT-09)},

address = {Paris, France},

abstract = {We present an efficient approach for discourse parsing within and across sentences, where the unit of processing is an entire document, and not a single sentence. We apply shift-reduce algorithms for dependency and constituent parsing to determine syntactic dependencies for the sentences in a document, and subsequently a Rhetorical Structure Theory (RST) tree for the entire document. Our results show that our linear-time shift-reduce framework achieves high accuracy and a large improvement in efficiency compared to a state-of-the-art approach based on chart parsing with dynamic programming.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{sagae_clustering_2009,

title = {Clustering Words by Syntactic Similarity Improves Dependency Parsing of Predicate-Argument Structures},

author = {Kenji Sagae and Andrew S. Gordon},

url = {http://ict.usc.edu/pubs/Clustering%20Words%20by%20Syntactic%20Similarity%20Improves%20Dependency%20Parsing%20of%20Predicate-Argument%20Structures.pdf},

year  = {2009},

date = {2009-10-01},

booktitle = {International Conference on Parsing Technologies (IWPT-09)},

address = {Paris, France},

abstract = {We present an approach for deriving syntactic word clusters from parsed text, grouping words according to their unlexicalized syntactic contexts. We then explore the use of these syntactic clusters in leveraging a large corpus of trees generated by a high-accuracy parser to improve the accuracy of another parser based on a different formalism for representing a different level of sentence structure. In our experiments, we use phrase-structure trees to produce syntactic word clusters that are used by a predicate-argument dependency parser, significantly improving its accuracy.},

keywords = {The Narrative Group, Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{devault_can_2009,

title = {Can I finish? Learning when to respond to incremental interpretation results in interactive dialogue},

author = {David DeVault and Kenji Sagae and David Traum},

url = {http://ict.usc.edu/pubs/Can%20I%20%EF%AC%81nish%20Learning%20when%20to%20respond%20to%20incremental%20interpretation%20results%20in%20interactive%20dialogue.pdf},

year  = {2009},

date = {2009-09-01},

booktitle = {10th SIGdial Workshop on Discourse and Dialogue},

address = {London, UK},

abstract = {We investigate novel approaches to responsive overlap behaviors in dialogue systems, opening possibilities for systems to interrupt, acknowledge or complete a user’s utterance while it is still in progress. Our specific contributions are a method for determining when a system has reached a point of maximal understanding of an ongoing user utterance, and a prototype implementation that shows how systems can use this ability to strategically initiate system completions of user utterances. More broadly, this framework facilitates the implementation of a range of overlap behaviors that are common in human dialogue, but have been largely absent in dialogue systems.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{lee_modeling_2009,

title = {Modeling Mutual Influence of Interlocutor Emotion States in Dyadic Spoken Interactions},

author = {Chi-Chun Lee and Carlos Busso and Sungbok Lee and Shrikanth Narayanan},

url = {http://ict.usc.edu/pubs/Modeling%20Mutual%20Influence%20of%20Interlocutor%20Emotion%20States%20in%20Dyadic%20Spoken%20Interactions.pdf},

year  = {2009},

date = {2009-09-01},

booktitle = {Proceedings of Interspeech 2009},

address = {Brighton, UK},

abstract = {In dyadic human interactions, mutual influence - a person's in- fluence on the interacting partner's behaviors - is shown to be important and could be incorporated into the modeling frame- work in characterizing, and automatically recognizing the par- ticipants' states. We propose a Dynamic Bayesian Network (DBN) to explicitly model the conditional dependency between two interacting partners' emotion states in a dialog using data from the IEMOCAP corpus of expressive dyadic spoken in- teractions. Also, we focus on automatically computing the Valence-Activation emotion attributes to obtain a continuous characterization of the participants' emotion flow. Our pro- posed DBN models the temporal dynamics of the emotion states as well as the mutual influence between speakers in a dialog. With speech based features, the proposed network improves classification accuracy by 3.67% absolute and 7.12% relative over the Gaussian Mixture Model (GMM) baseline on isolated turn-by-turn emotion classification.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{tsiartas_context-driven_2009,

title = {Context-driven automatic bilingual movie subtitle alignment},

author = {Andreas Tsiartas and Prasanta Kumar Ghosh and Panayiotis G. Georgiou and Shrikanth Narayanan},

url = {http://ict.usc.edu/pubs/Context-driven%20automatic%20bilingual%20movie%20subtitle%20alignment.pdf},

year  = {2009},

date = {2009-09-01},

booktitle = {Proceedings of Interspeech 2009},

address = {Brighton, UK},

abstract = {Movie subtitle alignment is a potentially useful approach for de- riving automatically parallel bilingual/multilingual spoken lan- guage data for automatic speech translation. In this paper, we consider the movie subtitle alignment task. We propose a dis- tance metric between utterances of different languages based on lexical features derived from bilingual dictionaries. We use the dynamic time warping algorithm to obtain the best alignment. The best F-score of ∼0.713 is obtained using the proposed ap- proach.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{mower_evaluating_2009,

title = {Evaluating Evaluators: A Case Study in Understanding the Benefits and Pitfalls of Multi-Evaluator Modeling},

author = {Emily Mower and Maja J. Mataric and Shrikanth Narayanan},

url = {http://ict.usc.edu/pubs/Evaluating%20Evaluators-%20A%20Case%20Study%20in%20Understanding%20the%20Benefits%20and%20Pitfalls%20of%20Multi-Evaluator%20Modeling.pdf},

year  = {2009},

date = {2009-09-01},

booktitle = {Proceedings of Interspeech 2009},

address = {Brighton, UK},

abstract = {Emotion perception is a complex process, often measured using stimuli presentation experiments that query evaluators for their perceptual ratings of emotional cues. These evaluations contain large amounts of variability both related and unrelated to the evaluated utterances. One approach to handling this variability is to model emotion perception at the individual level. However, the perceptions of specific users may not adequately capture the emotional acoustic properties of an utterance. This problem can be mitigated by the common technique of averaging evalu- ations from multiple users. We demonstrate that this averaging procedure improves classification performance when compared to classification results from models created using individual- specific evaluations. We also demonstrate that the performance increases are related to the consistency with which evaluators label data. These results suggest that the acoustic properties of emotional speech are better captured using models formed from averaged evaluations rather than from individual-specific eval- uations.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{von_der_putten_it_2009,

title = {It doesn't matter what you are! Comparing interacting with an autonomous virtual person with interacting with a virtually represented human},

author = {Astrid M. Pütten and Jonathan Gratch and Sin-Hwa Kang and Nicole Krämer},

url = {http://ict.usc.edu/pubs/It%20doesnt%20matter%20what%20you%20are.pdf},

year  = {2009},

date = {2009-09-01},

booktitle = {Proceedings of the 6th Conference of the Media Psychology Division of the German Psychological Society},

address = {University of Duisberg-Essen, Germany},

abstract = {According to the Threshold Model of Social Influence (Blascovich et al., 2002) the social influence of real persons will always be high, whereas the influence of an artificial entity depends on the realism of its behavior. Contrariwise, the Ethopeia concept (Nass & Moon, 2000) predicts that automatic social reactions are triggered by situations as soon as they include social cues. The presented study evaluates whether the participants' belief in interacting with either an avatar (a virtual representation of a human) or an agent (autonomous virtual person) lead to different social effects.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{lee_learning_2009,

title = {Learning Models of Speaker Head Nods with Affective Information},

author = {Jina Lee and Stacy C. Marsella},

url = {http://ict.usc.edu/pubs/Learning%20Models%20of%20Speaker%20Head%20Nods%20with%20Affective%20Information.pdf},

year  = {2009},

date = {2009-09-01},

booktitle = {The 3rd International Conference on Affective Computing and Intelligent Interaction (ACII 2009)},

address = {Amsterdam, The Netherlands},

abstract = {During face-to-face conversation, the speaker's head is continually in motion. These movements serve a variety of important communicative functions, and may also be influ- enced by our emotions. The goal for this work is to build a domain-independent model of speaker's head movements and investigate the effect of using affective information dur- ing the learning process. Once the model is learned, it can later be used to generate head movements for virtual agents. In this paper, we describe our machine-learning approach to predict speaker's head nods using an annotated corpora of face-to-face human interaction and emotion labels gener- ated by an affect recognition model. We describe the feature selection process, training process, and the comparison of results of the learned models under varying conditions. The results show that using affective information can help pre- dict head nods better than when no affective information is used.},

keywords = {Social Simulation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{de_melo_expression_2009-1,

title = {Expression of Moral Emotions in Cooperating Agents},

author = {Celso M. Melo and Liang Zheng and Jonathan Gratch},

url = {http://ict.usc.edu/pubs/Expression%20of%20Moral%20Emotions%20in%20Cooperating%20Agents.pdf},

year  = {2009},

date = {2009-09-01},

booktitle = {Proceedings of the 9th International Conference on Intelligent Virtual Agents (IVA)},

address = {Amsterdam, The Netherlands},

abstract = {Moral emotions have been argued to play a central role in the emergence of cooperation in human-human interactions. This work describes an experiment which tests whether this insight carries to virtual human-human interactions. In particular, the paper describes a repeated-measures experiment where subjects play the iterated prisoner's dilemma with two versions of the virtual human: (a) neutral, which is the control condition; (b) moral, which is identical to the control condition except that the virtual human expresses gratitude, distress, remorse, reproach and anger through the face according to the action history of the game. Our results indicate that subjects cooperate more with the virtual human in the moral condition and that they perceive it to be more human-like. We discuss the relevance these results have for building agents which are successful in cooperating with humans.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{de_melo_effect_2009,

title = {The Effect of Color on Expression of Joy and Sadness in Virtual Humans},

author = {Celso M. Melo and Jonathan Gratch},

url = {http://ict.usc.edu/pubs/The%20Effect%20of%20Color%20on%20Expression%20of%20Joy%20and%20Sadness%20in%20Virtual%20Humans.pdf},

year  = {2009},

date = {2009-09-01},

booktitle = {Proceedings of the 9th International Conference on Intelligent Virtual Agents (IVA)},

address = {Amsterdam, The Netherlands},

abstract = {For centuries artists have been exploring color to express emotions. Following this insight, the paper describes an approach to learn how to use color to influence the perception of emotions in virtual humans. First, a model of lighting and filters inspired on the visual arts is integrated with a virtual human platform to manipulate color. Next, an evolutionary model, based on genetic algorithms, is created to evolve mappings between emotions and lighting and filter parameters. A first study is, then, conducted where subjects evolve mappings for joy and sadness without being aware of the evolutionary model. In a second study, the features which characterize the mappings are analyzed. Results show that virtual human images of joy tend to be brighter, more saturated and have more colors than images of sadness. The paper discusses the relevance of the results for the fields of expression of emotions and virtual humans.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{kim_detailed_2009,

title = {A Detailed Study of Word-Position Effects on Emotion Expression in Speech},

author = {Jangwon Kim and Sungbok Lee and Shrikanth Narayanan},

url = {http://ict.usc.edu/pubs/A%20Detailed%20Study%20of%20Word-Position%20Effects%20on%20Emotion%20Expression%20in%20Speech.pdf},

year  = {2009},

date = {2009-09-01},

booktitle = {Proceedings of Interspeech 2009},

address = {Brighton UK},

abstract = {We investigate emotional effects on articulatory-acoustic speech characteristics with respect to word location within a sentence. We examined the hypothesis that emotional effect will vary based on word position by first examining articulatory features manually extracted from Electromagnetic articulography data. Initial articulatory data analyses indicated that the emotional effects on sentence medial words are significantly stronger than on initial words. To verify that observation further, we expanded our hypothesis testing to include both acoustic and articulatory data, and a consideration of an expanded set of words from different locations. Results suggest that emotional effects are generally more significant on sentence medial words than sentence initial and final words. This finding suggests that word location needs to be considered as a factor in emotional speech processing.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{wang_rapport_2009,

title = {Rapport and Facial Expression},

author = {Ning Wang and Jonathan Gratch},

url = {http://ict.usc.edu/pubs/Rapport%20and%20Facial%20Expression.pdf},

year  = {2009},

date = {2009-09-01},

booktitle = {3rd International Conference on Affective Computing and Intelligent Interaction (ACII 2009)},

address = {Amsterdam, The Netherlands},

abstract = {How to build virtual agents that establish rapport with human? According to Tickle-Degnen and Rosenthal [4], the three essential components of rapport are mutual attentiveness, positivity and coordination. In our previous work, we designed an embodied virtual agent to establish rapport with a human speaker by providing rapid and contingent nonverbal feedback [13] [22]. How do we know that a human speaker is feeling a sense of rapport? In this paper, we focus on the positivity component of rapport by investigating the relationship of human speakers' facial expressions on the establishment of rapport. We used an automatic facial expression coding tool called CERT to analyze the human dyad interactions and human-virtual human interactions. Results show that recognizing positive facial displays alone may be insufficient and that recognized negative facial displays was more diagnostic in assessing the level of rapport between participants.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{paksima_evaluating_2009,

title = {Evaluating the Effectiveness of Information Presentation in a Full End-To-End Dialogue System},

author = {Taghi Paksima and Kallirroi Georgila and Johanna D. Moore},

url = {http://ict.usc.edu/pubs/Evaluating%20the%20Effectiveness%20of%20Information%20Presentation%20in%20a%20Full%20End-To-End%20Dialogue%20System.pdf},

year  = {2009},

date = {2009-09-01},

booktitle = {10th SIGdial Workshop on Discourse and Dialogue},

pages = {1–10},

publisher = {Association for Computational Linguistics},

address = {London, UK},

abstract = {Recent work on information presenta- tion in dialogue systems combines user modelling (UM) and stepwise refine- ment through clustering and summarisa- tion (SR) in the UMSR approach. An eval- uation in which participants rated dialogue transcripts showed that UMSR presents complex trade-offs understandably, pro- vides users with a good overview of their options, and increases users' confidence that all relevant options have been pre- sented (Demberg and Moore, 2006). In this paper, we evaluate the effectiveness of the UMSR approach in a more realis- tic setting, by incorporating this informa- tion presentation technique into a full end- to-end dialogue system in the city infor- mation domain, and comparing it with the traditional approach of presenting infor- mation sequentially. Our results suggest that despite complications associated with a real dialogue system setting, the UMSR model retains its advantages.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{marsella_predicting_2009,

title = {Predicting Speaker Head Nods and the Effects of Affective Information},

author = {Stacy C. Marsella and Jina Lee},

url = {http://ict.usc.edu/pubs/Predicting%20Speaker%20Head%20Nods%20and%20the%20Effects%20of%20Affective%20Information.pdf},

year  = {2009},

date = {2009-09-01},

booktitle = {3rd International Conference on Affective Computing and Intelligent Interaction and Workshops},

volume = {12},

abstract = {During face-to-face conversation, our body is continually in motion with various head, gesture, and posture movements. Based on findings of the communicative functions served by these nonverbal behaviors, many virtual agent systems have modeled them to make the virtual agent look more effective and believable. One channel of nonverbal behaviors that has received less attention is head movements, despite the important functions served by them. The goal for this work is to build a domain-independent model of speaker's head movements that could be used to generate head movements for virtual agents. In this paper, we present a machine learning approach for learning models of head movements by focusing on when speaker head nods should occur and conduct evaluation studies that compare the nods generated by this work to our previous approach of using hand-crafted rules},

keywords = {Social Simulation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{han_improved_2009,

title = {Improved Speaker Diarization of Meeting Speech with Recurrent Selection of Representative Speech Segments and Participant Interaction Pattern Modeling},

author = {Kyu J. Han and Shrikanth Narayanan},

url = {http://ict.usc.edu/pubs/Improved%20Speaker%20Diarization.pdf},

year  = {2009},

date = {2009-09-01},

booktitle = {Proceedings of Interspeech 2009},

address = {Brighton, UK},

abstract = {In this work we describe two distinct novel improvements to our speaker diarization system, previously proposed for anal- ysis of meeting speech. The first approach focuses on recurrent selection of representative speech segments for speaker clus- tering while the other is based on participant interaction pat- tern modeling. The former selects speech segments with high relevance to speaker clustering, especially from a robust clus- ter modeling perspective, and keeps updating them throughout clustering procedures. The latter statistically models conver- sation patterns between meeting participants and applies it as a priori information when refining diarization results. Experi- mental results reveal that the two proposed approaches provide performance enhancement by 29.82% (relative) in terms of di- arization error rate in tests on 13 meeting excerpts from various meeting speech corpora.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{kang_interactants_2009,

title = {Interactants' Most Intimate Self-Disclosure in Interactions with Virtual Humans},

author = {Sin-Hwa Kang and Jonathan Gratch},

url = {http://ict.usc.edu/pubs/Interactants%E2%80%99%20Most%20Intimate%20Self-Disclosure%20in%20Interactions%20with%20Virtual%20Humans.pdf},

year  = {2009},

date = {2009-09-01},

booktitle = {9th International Conference on Intelligent Virtual Agents},

address = {Amsterdam, The Netherlands},

abstract = {This study explored the effect of the combination of visual fidelity of a virtual human and interactants' anticipated future interaction on self-disclosure in emotionally engaged and synchronous communication. The preliminary results were compared between interactions with embodied virtual agents and with real humans. We par-ticularly aimed at investigating ways to allow interactants' intimate self-disclosure while securing their anonymity, even with minimal cues of an embodied virtual agent, when interactants anticipate their future interaction with interaction partners. The results of preliminary data analysis showed that interactants revealed intimate information about their most common sexual fantasy when they had anticipated future interaction with their interaction partners.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{chance_method_2009,

title = {Method for Custom Facial Animation and Lip-Sync in an Unsupported Environment, Second Life},

author = {Eric Chance and Jacquelyn Morie},

url = {http://ict.usc.edu/pubs/Method%20for%20Custom%20Facial%20Animation%20and%20Lip-Sync%20in%20an%20Unsupported%20Environment,%20Second%20Life.pdf},

year  = {2009},

date = {2009-09-01},

booktitle = {Lecture Notes in Computer Science; Proceedings of the 9th International Workshop on Intelligent Virtual Agents (IVA)},

volume = {5773},

address = {Amsterdam, The Netherlands},

abstract = {The virtual world of Second Lifeâ„¢ does not offer support for complex facial animations, such as those needed for an intelligent virtual agent to lip sync to audio clips. However, it is possible to access a limited range of default facial animations through the native scripting language, LSL. Our solution to produce lip sync in this environment is to rapidly trigger and stop these default animations in custom sequences to produce the illusion that the intelligent virtual agent is speaking the phrases being heard.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{marsella_assessing_2009,

title = {Assessing the validity of a computational model of emotional coping},

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

url = {http://ict.usc.edu/pubs/Assessing%20the%20validity%20of%20a%20computational%20model%20of%20emotional%20coping.pdf},

year  = {2009},

date = {2009-09-01},

booktitle = {International Conference on Affective Computing and Intelligent Interaction},

address = {Amsterdam, The Netherlands},

abstract = {In this paper we describe the results of a rigorous empirical study evaluating the coping responses of a computational model of emotion. We discuss three key kinds of coping, Wishful Thinking, Resignation and Dis-tancing that impact an agent's beliefs, intentions and desires, and compare these coping responses to related work in the attitude change literature. We discuss the EMA computational model of emotion and identify sev-eral hypotheses it makes concerning these coping processes. We assess these hypotheses against the beha-vior of human subjects playing a competitive board game, using monetary gains and losses to induce emo-tion and coping. Subject's appraisals, emotional state and coping responses were indexed at key points throughout a game, revealing a pattern of subject's al-tering their beliefs, desires and intentions as the game unfolds. The results clearly support several of the hypo-theses on coping responses but also identify (a) exten-sions to how EMA models Wishful Thinking as well as (b) individual differences in subject's coping responses.},

keywords = {Social Simulation, Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{wilson_2d_2009,

title = {2D and 3D facial correspondences via photometric alignment},

author = {Cyrus A. Wilson and Abhijeet Ghosh and Pieter Peers and Jen-Yuan Chiang and Jay Busch and Paul Debevec},

url = {http://ict.usc.edu/pubs/2D%20and%203D%20facial%20correspondences%20via%20photometric%20alignment.pdf},

doi = {10.1145/1597990.1598018},

isbn = {978-1-60558-834-6},

year  = {2009},

date = {2009-08-01},

booktitle = {SIGGRAPH},

address = {New Orleans, LA},

abstract = {Capturing facial geometry that is high-resolution, yet easy to animate, remains a difficult challenge. While a single scanned geometry may be straightforward to animate smoothly, it may not always yield realistic fine scale detail when deformed into different facial expressions. Combining scans of multiple facial expressions, however, is only practical if geometrical correspondences between the different scanned expressions are available. Correspondences obtained based on locations of facial landmarks or of placed markers are often sparse, especially compared to fine-scale structures such as individual skin pores. The resulting misalignment of fine detail can introduce artifacts or blur out details we wish to preserve.},

keywords = {Graphics},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{vipperla_speech_2009,

title = {Speech Input from Older Users in Smart Environments: Challenges and perspectives},

author = {Ravichander Vipperla and Maria Wolters and Kallirroi Georgila and Steve Renals},

url = {http://ict.usc.edu/pubs/Speech%20Input%20from%20Older%20Users%20in%20Smart%20Environments.pdf},

year  = {2009},

date = {2009-07-01},

booktitle = {Proceedings of Human-Computer Interaction Intelligent and Ubiquitous Interaction Environments},

abstract = {Although older people are an important user group for smart envi- ronments, there has been relatively little work on adapting natural language in- terfaces to their requirements. In this paper, we focus on a particularly thorny problem: processing speech input from older users. Our experiments on the MATCH corpus show clearly that we need age-specific adaptation in order to recognize older users' speech reliably. Language models need to cover typical interaction patterns of older people, and acoustic models need to accommodate older voices. Further research is needed into intelligent adaptation techniques that will allow existing large, robust systems to be adapted with relatively small amounts of in-domain, age appropriate data. In addition, older users need to be supported with adequate strategies for handling speech recognition errors.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{hays_feedback_2009,

title = {Feedback Specificity and the Learning of Intercultural Communication Skills},

author = {Matthew Hays and H. Chad Lane and Daniel Auerbach and Mark Core and Dave Gomboc and Milton Rosenberg},

url = {http://ict.usc.edu/pubs/Feedback%20Specificity%20and%20the%20Learning%20of%20Intercultural%20Communication%20Skills.pdf},

year  = {2009},

date = {2009-07-01},

booktitle = {International Conference on Artificial Intelligence in Education},

address = {Brighton, UK},

abstract = {The role of explicit feedback in learning has been studied from a variety of perspectives and in many contexts. In this paper, we examine the impact of the specificity of feedback delivered by an intelligent tutoring system in a game-based environment for cultural learning. We compared two versions: one that provided only "bottom-out" hints and feedback versus one that provided only conceptual messages. We measured during-training performance, in-game transfer, and long- term retention. Consistent with our hypotheses, specific feedback utterances produced inferior learning on the in-game transfer task when compared to conceptual utterances. No differences were found on a web-based post-test. We discuss possible explanations for these findings, particularly as they relate to the learning of loosely defined skills and serious games.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{traum_models_2009,

title = {Models of Culture for Virtual Human Conversation},

author = {David Traum},

url = {http://ict.usc.edu/pubs/Models%20of%20Culture%20for%20Virtual%20Human%20Conversation.pdf},

year  = {2009},

date = {2009-07-01},

booktitle = {Human Computer Interaction International (HCII)},

pages = {434–440},

address = {San Diego, CA},

abstract = {In this paper, we survey different types of Models of culture for virtual humans. Virtual humans are artificial agents that include both a visual human-like body and intelligent cognition driving action of the body. Culture covers a wide range of common knowledge of behavior and communication that can be used in a number of ways including interpreting the meaning of ac- tion, establishing identity, expressing meaning, and inference about the per- former. We look at several examples of existing cultural models and point out remaining steps for a more full model of culture.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{rosenbloom_towards_2009,

title = {Towards a New Cognitive Hourglass: Uniform Implementation of Cognitive Architecture via Factor Graphs},

author = {Paul Rosenbloom},

url = {http://ict.usc.edu/pubs/Towards%20a%20New%20Cognitive%20Hourglass.pdf},

year  = {2009},

date = {2009-07-01},

booktitle = {Proceedings of the 9th International Conference on Cognitive Modeling (ICCM 2009)},

address = {Manchester, UK},

abstract = {As cognitive architectures become ever more ambitious in the range of phenomena they are to assist in producing and modeling, there is increasing pressure for diversity in the mechanisms they embody. Yet uniformity remains critical for both elegance and extensibility. Here, the search for uniformity is continued, but shifted downwards in the cognitive hierarchy to the implementation level. Factor graphs are explored as a promising core, with initial steps towards a reimplementation of Soar. The ultimate aim is a uniform implementation level for cognitive architectures affording both heightened elegance and expanded coverage.},

keywords = {CogArch, Cognitive Architecture, Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{wang_can_2009,

title = {Can Virtual Human Build Rapport and Promote Learning?},

author = {Ning Wang and Jonathan Gratch},

url = {http://ict.usc.edu/pubs/Can%20Virtual%20Human%20Build%20Rapport%20and%20Promote%20Learning.pdf},

year  = {2009},

date = {2009-07-01},

booktitle = {Annual Conference on Artificial Intelligence in Education},

address = {Brighton UK},

abstract = {Research show that teacher’s nonverbal immediacy can have a positive impact on student’s cognitive learning and affect [31]. This paper investigates the effectiveness of nonverbal immediacy using a virtual human. The virtual human attempts to use immediacy feedback to create rapport with the learner. Results show that the virtual human established rapport with learners but did not help them achieve better learning results. The results also suggest that creating rapport is related to higher self-efficacy, and self-efficacy is related to better learning results.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{lane_pedagogical_2009,

title = {Pedagogical Experience Manipulation for Cultural Learning},

author = {H. Chad Lane and Mark Core and Eric Forbell and Robert Wray and Brian Stensrud and Laura Hamel},

url = {http://ict.usc.edu/pubs/Pedagogical%20Experience%20Manipulation%20for%20Cultural%20Learning.pdf},

year  = {2009},

date = {2009-07-01},

booktitle = {Proceedings of the Workshop on Culturally Aware Tutoring Systems, 14th International Conference on AI in Education},

abstract = {Acquiring intercultural competence is challenging. Although intelligent learning environments developed to enhance cultural learning can be effective, there is limited evidence regarding how best to dynamically manipulate these environments in support of learning. Further, the space of potential manipulations is extremely large and sometimes tangled with the implementation details of particular learning systems in particular domains. This paper offers a framework for organizing approaches to such dynamic tailoring of the learning experience. The framework is hypothesized to be useful as a general tool for the community to organize and present alternative approaches to tailoring. To highlight the use of the framework, we examine one potential tailoring option in detail in the context of an existing simulation for learning intercultural competence.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{mcalinden_urbansim_2009,

title = {UrbanSim: A Game-based Simulation for Counterinsurgency and Stability-focused Operations},

author = {Ryan McAlinden and Andrew S. Gordon and H. Chad Lane and David V. Pynadath},

url = {http://ict.usc.edu/pubs/UrbanSim-%20A%20Game-based%20Simulation%20for%20Counterinsurgency%20and%20Stability-focused%20Operations.pdf},

year  = {2009},

date = {2009-07-01},

booktitle = {Workshop on Intelligent Educational Games, 14th International Conference on Artificial Intelligence in Education},

address = {Brighton, UK},

abstract = {The UrbanSim Learning Package is a simulation-based training application designed for the U.S. Army to develop commanders' skills for conducting counterinsurgency operations. UrbanSim incorporates multiple artificial intelligence (AI) technologies in order to provide an effective training experience, three of which are described in this paper. First, UrbanSim simulates the mental attitudes and actions of groups and individuals in an urban environment using the PsychSim reasoning engine. Second, UrbanSim interjects narrative elements into the training experience using a case-based story engine, driven by non-fiction stories told by experienced commanders. Third, UrbanSim provides intelligent tutoring using a simulation-based method for eliciting and evaluating learner decisions. UrbanSim represents a confluence of AI techniques that seek to bridge the gap between basic research and deployed AI systems.},

keywords = {Learning Sciences, Social Simulation, The Narrative Group},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{gandhe_integrated_2009,

title = {An Integrated Authoring Tool for Tactical Questioning Dialogue Systems},

author = {Sudeep Gandhe and Nicolle Whitman and David Traum and Ron Artstein},

url = {http://ict.usc.edu/pubs/An%20Integrated%20Authoring%20Tool%20for%20Tactical%20Questioning%20Dialogue%20Systems.pdf},

year  = {2009},

date = {2009-07-01},

booktitle = {Workshop on Knowledge and Reasoning in Practical Dialogue Systems},

address = {Pasadena, CA},

abstract = {We present an integrated authoring tool for rapid prototyping of dialogue systems for virtual humans taking part in tactical questioning simulations. The tool helps domain experts, who may have little or no knowledge of linguistics or computer science, to build virtual characters that can play the role of the interviewee. Working in a top-down fashion, the authoring process begins with specifying a domain of knowledge for the character; the authoring tool generates all relevant dialogue acts and allows authors to assign the language that will be used to refer to the domain elements. The authoring tool can also be used to manipulate some aspects of the dialogue strategies employed by the virtual characters, and it also supports re-using some of the authored content across different characters.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{georgila_using_2009,

title = {Using Integer Linear Programming for Detecting Speech Disfluencies},

author = {Kallirroi Georgila},

url = {http://ict.usc.edu/pubs/Using%20Integer%20Linear%20Programming%20for%20Detecting%20Speech%20Disfluencies.pdf},

year  = {2009},

date = {2009-06-01},

booktitle = {Proceedings of the NAACL HLT 2009: Short Papers},

pages = {109–112},

address = {Boulder, CO},

abstract = {We present a novel two-stage technique for detecting speech disfluencies based on Integer Linear Programming (ILP). In the first stage we use state-of-the-art models for speech disfluency detection, in particular, hidden-event language models, maximum entropy models and conditional random fields. During testing each model proposes possible disfluency labels which are then assessed in the presence of global constraints using ILP. Our experimental results show that by using ILP we can improve significantly the performance of our models with negligible cost in processing time. The less training data is available the larger the improvement due to ILP.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{artstein_viability_2009,

title = {Viability of a Simple Dialogue Act Scheme for a Tactical Questioning Dialogue System},

author = {Ron Artstein and Sudeep Gandhe and Michael Rushforth and David Traum},

url = {http://ict.usc.edu/pubs/Viability%20of%20a%20Simple%20Dialogue%20Act%20Scheme%20for%20a%20Tactical%20Questioning%20Dialogue%20System.pdf},

year  = {2009},

date = {2009-06-01},

booktitle = {DiaHolmia 2009, the 13th Annual Workshop on the Semantics and Pragmatics of Dialogue},

pages = {43–50},

address = {Stockholm, Sweden},

abstract = {User utterances in a spoken dialogue sys- tem for tactical questioning simulation were matched to a set of dialogue acts gen- erated automatically from a representation of facts as ⟨object, attribute, value⟩ triples and actions as ⟨character, action⟩ pairs. The representation currently covers about 50% of user utterances, and we show that a few extensions can increase coverage to 80% or more. This demonstrates the vi- ability of simple schemes for represent- ing question-answering dialogues in im- plemented systems.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{sagae_towards_2009,

title = {Towards Natural Language Understanding of Partial Speech Recognition Results in Dialogue Systems},

author = {Kenji Sagae and Gwen Christian and David DeVault and David Traum},

url = {http://ict.usc.edu/pubs/Towards%20Natural%20Language%20Understanding%20of%20Partial%20Speech%20Recognition%20Results%20in%20Dialogue%20Systems.pdf},

year  = {2009},

date = {2009-06-01},

booktitle = {Short Paper Proceedings of NAACL HLT 2009},

address = {Boulder, CO},

abstract = {We investigate natural language understand- ing of partial speech recognition results to equip a dialogue system with incremental lan- guage processing capabilities for more realis- tic human-computer conversations. We show that relatively high accuracy can be achieved in understanding of spontaneous utterances before utterances are completed.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{lane_using_2009,

title = {Using Written and Behavioral Data to Detect Evidence of Continuous Lear ning},

author = {H. Chad Lane and Mark Core and Dave Gomboc and Mike Birch and John Hart and Milton Rosenberg},

url = {http://ict.usc.edu/pubs/Using_Written_and_Behavioral_Data.pdf},

year  = {2009},

date = {2009-06-01},

booktitle = {Proceedings of the User Modeling, Adaptation and Personalization (UMAP) Workshop on Lifelong Learner Modeling},

pages = {54–61},

address = {Trento, Italy},

abstract = {We describe a lifelong learner modeling project that focuses on the use of written and behavioral data to detect patterns of learning over time. Related work in essay analysis and machine learning is discussed. Although primarily focused on isolated learning experiences, we argue there is promise for scaling these techniques up to the lifelong learner modeling problem.},

keywords = {},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{ghosh_estimating_2009,

title = {Estimating Specular Roughness and Anisotropy from Second Order Spherical Gradient Illumination},

author = {Abhijeet Ghosh and Tongbo Chen and Pieter Peers and Cyrus A. Wilson and Paul Debevec},

url = {http://ict.usc.edu/pubs/Estimating%20Specular%20Roughness%20and%20Anisotropy%20from%20Second%20Order%20Spherical%20Gradient%20Illumination.pdf},

year  = {2009},

date = {2009-06-01},

booktitle = {Computer Graphics Forum},

volume = {28},

pages = {4},

abstract = {This paper presents a novel method for estimating specular roughness and tangent vectors, per surface point, from polarized second order spherical gradient illumination patterns. We demonstrate that for isotropic BRDFs, only three second order spherical gradients are sufficient to robustly estimate spatially varying specular roughness. For anisotropic BRDFs, an additional two measurements yield specular roughness and tangent vectors per surface point. We verify our approach with different illumination configurations which project both discrete and continuous fields of gradient illumination. Our technique provides a direct estimate of the per-pixel specular roughness and thus does not require off-line numerical optimization that is typical for the measure-and-fit approach to classical BRDF modeling.},

keywords = {Graphics},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{op_den_akker_comparison_2009,

title = {A comparison of addressee detection methods for multiparty conversations},

author = {Rieks Akker and David Traum},

url = {http://ict.usc.edu/pubs/A%20comparison%20of%20addressee%20detection%20methods%20for%20multiparty%20conversations.pdf},

year  = {2009},

date = {2009-06-01},

booktitle = {DiaHolmia 2009, the 13th Annual Workshop on the Semantics and Pragmatics of Dialogue},

address = {Stockholm, Sweden},

abstract = {Several algorithms have recently been pro- posed for recognizing addressees in a group conversational setting. These al- gorithms can rely on a variety of factors including previous conversational roles, gaze, and type of dialogue act. Both statistical supervised machine learning al- gorithms as well as rule based methods have been developed. In this paper, we compare several algorithms developed for several different genres of multiparty di- alogue, and propose a new synthesis al- gorithm that matches the performance of machine learning algorithms while main- taining the transparency of semantically meaningful rule-based algorithms.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{flynn_overview_2009,

title = {An overview of a USC Rehabilitation Engineering Research Center: The use of virtual reality for a range of motor impairments},

author = {Sheryl Flynn and Belinda Lange and Albert Rizzo and F. J. Valero-Cuevas and L. Baker and Carolee J. Winstein},

url = {http://ict.usc.edu/pubs/An%20overview%20of%20a%20USC%20Rehabilitation%20Engineering%20Research%20Center-%20The%20use%20of%20virtual%20reality%20for%20a%20range%20of%20motor%20impairments.pdf},

year  = {2009},

date = {2009-06-01},

booktitle = {Virtual Rehabilitation International Conference},

abstract = {This paper describes the use of Virtual Reality in four projects within a Rehabilitation Engineering Research Center at the University of Southern California. The Research Center aims to develop and assess a range of technologies for people aging with and into a disability. One of the deliverables of this Center will be the development of a Virtual Rehabilitation Toolkit, a series of Virtual Reality video based games for use with a range of impairments for a variety of disabilities including spinal cord injury, traumatic brain injury, stroke, Parkinson's disease, and cerebral palsy.},

keywords = {MedVR},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{wang_dont_2009,

title = {Don't Just Stare at Me!},

author = {Ning Wang and Jonathan Gratch},

url = {http://www.ict.usc.edu/pubs/Don't%20Just%20Stare%20at%20Me.pdf},

year  = {2009},

date = {2009-06-01},

booktitle = {28th ACM Conference on Human Factors in Computing Systems},

address = {Chicago, IL},

abstract = {Communication is more effective and persuasive when par- ticipants establish rapport. Tickle-Degnen and Rosenthal [57] argue rapport arises when participants exhibit mutual attentiveness, positivity and coordination. In this paper, we investigate how these factors relate to perceptions of rap- port when users interact via avatars in virtual worlds. In this study, participants told a story to what they believed was the avatar of another participant. In fact, the avatar was a computer program that systematically manipulated levels of attentiveness, positivity and coordination. In contrast to Tickel-Degnen and Rosenthal's findings, high-levels of mutual attentiveness alone can dramatically lower percep- tions of rapport in avatar communication. Indeed, an agent that attempted to maximize mutual attention performed as poorly as an agent that was designed to convey boredom. Adding positivity and coordination to mutual attentiveness, on the other hand, greatly improved rapport. This work un- veils the dependencies between components of rapport and informs the design of agents and avatars in computer medi- ated communication.},

keywords = {Virtual Humans},

pubstate = {published},

tppubtype = {inproceedings}

}