Intelligent Interfaces: Pedagogical Agents and Virtual Humans

Little by little, we are entering the new era, intelligent interfaces are absorbing us more and more every day, and artificial intelligence makes its presence in a stealthy way. Virtual humans that represent an evolution of autonomous virtual agents;they are computer programs and in the future capable of carrying out different activities in certain environments. They will give the illusion of being human;they will have a body, and they will be immersed in an environment. They will have a set of senses that will allow them: 1) Sensations and therefore associated expressions;2) Communication;3) Learning;4) Remembering events, among others. By integrating the above, they will have a personality and autonomy, so they will be able to plan with respect to objectives;allowing them to decide and take actions with their body, in other words, they will count on awareness. The applications will be focused on environments that they will inhabit, or as interfaces that will interact with other systems. The application domains will be multiple;one of them being education. This article shows the design of OANNA like an avatar with the role of pedagogical agent. It was modeled as an affective-cognitive structure related to the teaching-learning process linked to a pedagogical agent that represents the interface of an artilect. OANNA, has the necessary animations for intervention within the teaching-learning process.

Human-Machine Symbiosis:Philosophical Reflection on Virtual Human

Virtual human is the simulation of human under the synthesis of virtual reality,artificial intelligence,and other technologies.Modern virtual human technology simulates both the external characteristics and the internal emotions and personality of humans.The relationship between virtual human and human is a concrete expression of the modern symbiotic relationship between human and machine.This human-machine symbiosis can either be a fusion of the virtual human and the human or it can cause a split in the human itself.

Emotion model of interactive virtual humans on the basis of MDP

Emotion plays an essential role in the adaptation and social communication of organisms.Similarly,an appro-priately timed and clearly expressed emotion is a central requirement for believable interactive virtual humans.Presently,incorporating emotion into virtual humans has gained increasing attention in the academia and industry.This strong interest is driven by a wide spectrum of promising applications in many areas such as virtual reality,e-learning,entertainment,etc.This paper introduces an emotion model of artificial psychology,in which the transition of emotion can be viewed as a Markov process and the relation of emotion,external incentive and personality can be described by a Markov decision process(MDP).In order to demonstrate the approach,this paper integrates the emotion model into a system composed of voice recognition and a realistic facial model.Thus,the model could be used for generating a variety of emotional expressions of autonomous,interactive virtual human beings.

Creating Autonomous, Perceptive and Intelligent Virtual Humans in a Real-Time Virtual Environment

Creating realistic virtual humans has been a challenging objective in computer science research for some time. This paper describes an integrated framework for modeling virtual humans with a high level of autonomy. The framework seeks to reproduce human-like believable behavior and movement in virtual humans in a virtual environment. The framework includes a visual and auditory information perception module, a decision network based behavior decision module, and a hierarchical autonomous motion control module. These cooperate to model realistic autonomous individual behavior for virtual humans in real-time interactive virtual environments. The framework was tested in a simulated virtual environment system to demonstrate the ability of the framework to create autonomous, perceptive and intelligent virtual humans in real-time virtual environments.

Cyber-Physical-Social System Between a Humanoid Robot and a Virtual Human Through a Shared Platform for Adaptive Agent Ecology

Two artificial agents(a humanoid robot and a virtual human) are enriched with various similar intelligence,autonomy, functionalities and interaction modalities. The agents are integrated in the form of a cyber-physical-social system(CPSS) through a shared communication platform to create a social ecology. In the ecology, the agents collaborate(assist each other) to perform a real-world task(search for a hidden object)for the benefits of humans. A robot-virtual human bilateral trust model is derived and a real-time trust measurement method is developed. The role of taking initiative in the collaboration is switched between the agents following a finite state machine model triggered by bilateral trust, which results in a mixedinitiative collaboration. A scheme is developed to evaluate the performance of the agents in the ecology through the CPSS.The results show that the robot and the virtual human perform satisfactorily in the collaboration through the CPSS. The results thus prove the effectiveness of the real-world ecology between artificial agents of heterogeneous realities through a shared platform based on trust-triggered mixed-initiatives. The results can help develop adaptive social ecology comprising intelligent agents of heterogeneous realities to assist humans in various tasks through collaboration between the agents in the form of a CPSS.

Human Centered Design in Multi-agent Virtual Environment

The efficient and reliable human centered design of products and processes is a major goal in manufacturing industries for numerous human factors must be taken into account during the entire life cycle of products. A multi-agents intelligent design system is presented for manufacturing process simulation and products＇ ergonomic analysis. In virtual design environment, the virtual human with high-level intelligence performs tasks＇ operation autonomously and shows optimum posture configuration with ergonomic assessment results in real time. The functions are realized by intelligent agents architecture based on a modem approach derived from fuzzy multi-objects decision-making theory. A case study is presented to demonstrate the feasibility of the suggested methodology.

The Skin Deformation of a 3D Virtual Human

This paper presents a skin deformation algorithm for creating 3D characters or virtual human models. The algorithm can be applied to rigid deformation, joint dependent localized deformation, skeleton driven deformation, cross contour deformation, and free-form deformation （FFD）. These deformations are computed and demonstrated with examples and the algorithm is applied to overcome the difficulties in mechanically simulating the motion of the human body by club-shape models. The techniques described in this article enables the reconstruction of dynamic human models that can be used in defining and representing the geometrical and kinematical characteristics of human motion.

Forecasting display technique of human in network virtual environment

The simulation of human in the distributed virtual environment is different from the simulation of vehicle. Due to the human’s many joints, to implement the real time performance of the interaction between the virtual human and the environment, the quantity of information broadcasted in the network will be increased. So with the growing of the quantity of virtual human added to the network, the network burthen would augment rapidly. Therefore, for the simulation of virtual human this paper divides organically the motion parts of the body, which makes those body parts that often interact with the environment are described according to the joints while other parts are described according to the action information. Simultaneity, this paper adopts Dead Reckoning to reduce the quantity of information needed by maintaining the reality motion of virtual human. The experiment indicates that the forecasting display technique can efficiently reduce the network burthen and enhance the interaction of virtual human.

Virtual Temporal Bone Anatomy

Background The Visible Human Project(VHP) initiated by the U.S. National Library of Medicine has drawn much attention and interests from around the world. The Visible Chinese Human(VCH) project has started in China. The current study aims at acquiring a feasible virtual methodology for reconstructing the temporal bone of the Chinese population, which may provide an accurate 3-D model of important temporal bone structures that can be used in teaching and patient care for medical scientists and clinicians. Methods A series of sectional images of the temporal bone were generated from section slices of a female cadaver head. On each sectional image, SOIs (structures of interest) were segmented by carefully defining their contours and filling their areas with certain gray scale values. The processed volume data were then inducted into the 3D Slicer software(developed by the Surgical Planning Lab at Brigham and Women’s Hospital and the MIT AI Lab) for resegmentation and generation of a set of tagged images of the SOIs. 3D surface models of SOIs were then reconstructed from these images. Results The temporal bone and structures in the temporal bone, including the tympanic cavity, mastoid cells, sigmoid sinus and internal carotid artery, were successfully reconstructed. The orientation of and spatial relationship among these structures were easily visualized in the reconstructed surface models. Conclusion The 3D Slicer software can be used for 3- dimensional visualization of anatomic structures in the temporal bone, which will greatly facilitate the advance of knowledge and techniques critical for studying and treating disorders involving the temporal bone.

Application of Question and Answering on Virtual Human Dialogue:a Review and Prediction

Nowadays,virtual human(VH) is becoming a hot research topic in virtualization.VH dialogue can be categorized as an application of natural language processing(NLP) technology,since it is relational to question and answering(QA) technologies.In order to integrate these technologies,this paper reviews some important work on VH dialogue,and predicts some research points on the view of QA technologies.

Uncanny valley for interactive social agents:an experimental study

Background The uncanny valley hypothesis states that users may experience discomfort when inter-acting with almost human-like artificial characters.Advancements in artificial intelligence,robotics,and computer graphics have led to the development of life-like virtual humans and humanoid robots.Revisiting this hypothesis is necessary to check whether they positively or negatively affect the current population,who are highly accustomed to the latest technologies.Methods In this study,we present a unique evaluation of the uncanny valley hypothesis by allowing participants to interact live with four humanoid robots that have varying levels of human-likeness.Each participant completed a survey questionnaire to evaluate the affinity of each robot.Additionally,we used deep learning methods to quantify the participants’emotional states using multimodal cues,including visual,audio,and text cues,by recording the participant-robot interactions.Results Multi-modal analysis and surveys provided interesting results and insights into the uncanny valley hypothesis.

Empathic Responses of Behavioral-Synchronization in Human-Agent Interaction

Artificial entities,such as virtual agents,have become more pervasive.Their long-term presence among humans requires the virtual agent’s ability to express appropriate emotions to elicit the necessary empathy from the users.Affective empathy involves behavioral mimicry,a synchronized co-movement between dyadic pairs.However,the characteristics of such synchrony between humans and virtual agents remain unclear in empathic interactions.Our study evaluates the participant’s behavioral synchronization when a virtual agent exhibits an emotional expression congruent with the emotional context through facial expressions,behavioral gestures,and voice.Participants viewed an emotion-eliciting video stimulus(negative or positive)with a virtual agent.The participants then conversed with the virtual agent about the video,such as how the participant felt about the content.The virtual agent expressed emotions congruent with the video or neutral emotion during the dialog.The participants’facial expressions,such as the facial expressive intensity and facial muscle movement,were measured during the dialog using a camera.The results showed the participants’significant behavioral synchronization(i.e.,cosine similarity≥.05)in both the negative and positive emotion conditions,evident in the participant’s facial mimicry with the virtual agent.Additionally,the participants’facial expressions,both movement and intensity,were significantly stronger in the emotional virtual agent than in the neutral virtual agent.In particular,we found that the facial muscle intensity of AU45(Blink)is an effective index to assess the participant’s synchronization that differs by the individual’s empathic capability(low,mid,high).Based on the results,we suggest an appraisal criterion to provide empirical conditions to validate empathic interaction based on the facial expression measures.

Recent advances on virtual human synthesis

Virtual human is a digital representation of the geometric and behavioral property of human beings in the virtual environment generated by computer. The research goal of virtual human synthesis is to generate realistic human body models and natural human motion behavior. This paper introduces the development of the related researches on these two topics, and some progresses on example based human modeling and motion synthesis, and their applications in Chinese sign language teaching, computeraided sports training and public safety problem studying. Finally, some hot research topics in virtual human synthesis are presented.

Real-time interactive motion control of virtual human in virtual maintenance based on limited information

In order to provide a simple and efficient approach to perform the real-time interactive motion control of virtual human in virtual maintenance environment(VME),the motion control method of virtual human based on limited input information is proposed.With the space position tracking system with only one sensor the action sequences and motion models of virtual human,the human motions and hand actions in VME are driven by the sensor data in stages and in real time through the transmission condition control in the process of maintenance operation.And the input data and information is processed based on the method of Kalman filtering and wavelet transforming to improve the control effects.An experimental VME is also established to validate the control efficiency,and the experiment results show that the space motion control of virtual human in VME can be performed based on limited information with proposed control strategy.

Fatigue Analysis and Evaluation Method of Ergonomic Virtual Human

The ergonomic digital design and evaluation of man-machine system is the main application fields of virtual human technology. Because of the complexity of physical person and uncertainty of fatigue generation mechanism, it is difficult to express a nd evaluate the Virtual Human's fatigue state. This paper summarizes the characteristics of virtual human's fatigue evaluation, such as undeterminable, invisible, the constraint conditions can been used. Viewed from the strengths and weaknesses of preexisting models, metabolic energy expenditure model, dynamic muscle fatigue model and a model to assess fatigue at joint-level using the half-joint concept, this paper puts forward the future development trend that the combination of subjective and objective,diversificationoftheanalyzablemotion,real-timeandvisualexpression.

Application of three-dimensional digitalized reconstruction of latissimus dorsi myocutaneous flap

Developments of digital technology and three-dimensional(3D)reconstruction allowed a precise description of anatomic structures.With the introduction of Visible Human Project and Virtual Chinese Human(VCH)techniques,more detailed anatomic images could be obtained.Digitized visible models of these structures can be applied as a useful tool in clinical training.The aim of this study was to reconstruct the normal structures of thoracodorsal artery in 3D images and to establish the digitized visible models of latissimus dorsi myocutaneous(LDM)flap.The cross-sectional images from the four VCH datasets were reviewed to study LDM and thoraco-dorsal artery structures on a section-by-section basis.Next,two adult fresh cadaver specimens were perfused with lead oxide-gelatine mixture and subject to radio-graphic CT scanning on their torsos.The cross-sectional images from the CT images were reviewed to study thor-acodorsal artery structures.Three-dimensional computer-ized reconstructions of LDM flap structures were conducted from these datasets by using Amira 3.1(TGS)software respectively.The 3D reconstructed visible models established from these datasets perfectly displayed the anatomic characteristics of LDM flap.