Application of JXTA-overlay platform for secure robot control

In this paper, we present the evaluation and experimental results of secured robot control in a P2P system. The control system is based on JXTA-Overlay platform. We used secure primitives and functions of JXTA-Overlay for the secure control of the robot motors. We investigated the time of robot control for some scenarios with different number of peers connected in JXTA-Overlay network. All experiments are realised in a LAN environment. The experimental results show that with the join of other peers in the network, the average time of robot control is increased, but the difference between the secure and unsecure robot control average time is nearly the samePeer ReviewedPostprint (published version

Discovery and recognition of motion primitives in human activities

We present a novel framework for the automatic discovery and recognition of motion primitives in videos of human activities. Given the 3D pose of a human in a video, human motion primitives are discovered by optimizing the `motion flux', a quantity which captures the motion variation of a group of skeletal joints. A normalization of the primitives is proposed in order to make them invariant with respect to a subject anatomical variations and data sampling rate. The discovered primitives are unknown and unlabeled and are unsupervisedly collected into classes via a hierarchical non-parametric Bayes mixture model. Once classes are determined and labeled they are further analyzed for establishing models for recognizing discovered primitives. Each primitive model is defined by a set of learned parameters. Given new video data and given the estimated pose of the subject appearing on the video, the motion is segmented into primitives, which are recognized with a probability given according to the parameters of the learned models. Using our framework we build a publicly available dataset of human motion primitives, using sequences taken from well-known motion capture datasets. We expect that our framework, by providing an objective way for discovering and categorizing human motion, will be a useful tool in numerous research fields including video analysis, human inspired motion generation, learning by demonstration, intuitive human-robot interaction, and human behavior analysis

Development of bipedal and quadrupedal locomotion in humans from a dynamical systems perspective

The first phase in the development 0f locomotion, pr,öary variability would occur in normal fetuses and infants, and those with Uner Tan syndrome. The neural networks for quadrupedal locomotion have apparently been transmitted epigenetically through many species since about 400 MYA.\ud The second phase is the neuronal selection process. During infancy, the most effective motor pattern(s) and their associated neuronal group(s) are selected through experience.\ud The third phase, secondary or adaptive variability, starts to bloom at two to three years of age and matures in adolescence. This third phase may last much longer in some patients with Uner Tan syndrome, with a considerably delay in selection of the well-balanced quadrupedal locomotion, which may emerge very late in adolescence in these cases

From motor babbling to hierarchical learning by imitation: a robot developmental pathway

How does an individual use the knowledge acquired through self exploration as a manipulable model through which to understand others and benefit from their knowledge? How can developmental and social learning be combined for their mutual benefit? In this paper we review a hierarchical architecture (HAMMER) which allows a principled way for combining knowledge through exploration and knowledge from others, through the creation and use of multiple inverse and forward models. We describe how Bayesian Belief Networks can be used to learn the association between a robot’s motor commands and sensory consequences (forward models), and how the inverse association can be used for imitation. Inverse models created through self exploration, as well as those from observing others can coexist and compete in a principled unified framework, that utilises the simulation theory of mind approach to mentally rehearse and understand the actions of others

Intrinsic Motivation Systems for Autonomous Mental Development

Exploratory activities seem to be intrinsically rewarding for children and crucial for their cognitive development. Can a machine be endowed with such an intrinsic motivation system? This is the question we study in this paper, presenting a number of computational systems that try to capture this drive towards novel or curious situations. After discussing related research coming from developmental psychology, neuroscience, developmental robotics, and active learning, this paper presents the mechanism of Intelligent Adaptive Curiosity, an intrinsic motivation system which pushes a robot towards situations in which it maximizes its learning progress. This drive makes the robot focus on situations which are neither too predictable nor too unpredictable, thus permitting autonomous mental development.The complexity of the robot’s activities autonomously increases and complex developmental sequences self-organize without being constructed in a supervised manner. Two experiments are presented illustrating the stage-like organization emerging with this mechanism. In one of them, a physical robot is placed on a baby play mat with objects that it can learn to manipulate. Experimental results show that the robot first spends time in situations which are easy to learn, then shifts its attention progressively to situations of increasing difficulty, avoiding situations in which nothing can be learned. Finally, these various results are discussed in relation to more complex forms of behavioral organization and data coming from developmental psychology. Key words: Active learning, autonomy, behavior, complexity, curiosity, development, developmental trajectory, epigenetic robotics, intrinsic motivation, learning, reinforcement learning, values

Primitive roles for inhibitory interneurons in developing frog spinal cord

Understanding the neuronal networks in the mammal spinal cord is hampered by the diversity of neurons and their connections. The simpler networks in developing lower vertebrates may offer insights into basic organization. To investigate the function of spinal inhibitory interneurons in Xenopus tadpoles, paired whole-cell recordings were used. We show directly that one class of interneuron, with distinctive anatomy, produces glycinergic, negative feedback inhibition that can limit firing in motoneurons and interneurons of the central pattern generator during swimming. These same neurons also produce inhibitory gating of sensory pathways during swimming. This discovery raises the possibility that some classes of interneuron, with distinct functions later in development, may differentiate from an earlier class in which these functions are shared. Preliminary evidence suggests that these inhibitory interneurons express the transcription factor engrailed, supporting a probable homology with interneurons in developing zebrafish that also express engrailed and have very similar anatomy and functions

Two New Cases of Uner Tan Syndrome: One Man\ud with Transition from Quadrupedalism to Bipedalism;\ud One Man with Consistent Quadrupedalism

Background: Uner Tan syndrome, first described in\ud 2005, consists of three main symptoms: habitual\ud locomotion on all four extremities, impaired\ud intelligence, and dysarthric or no speech. This\ud extremely rare syndrome shows an autosomal\ud recessive inheritance due to consanguineous\ud marriages between parents. In general, there is a\ud cerebellovermial hypoplasia with a mild gyral\ud simplification in the cerebral cortex. Truncal ataxia is\ud the main neurological finding, causing difficulty in\ud standing and upright walking on two legs.\ud Methods: As soon as the new cases came to light, the\ud family was visited. After taking the basic information\ud about the family members, the traditional neurological\ud examinations were performed, MRI scans of the\ud patients and of a healthy family member were taken in\ud a hospital nearest to the residence (a small village\ud near Kars, Turkey). The patients were also filmed to\ud analyze their walking patterns.\ud Results: Two individuals (case 1, 44y; case 2, 43y)\ud among six siblings from a family with consanguineous\ud parents exhibited Uner Tan syndrome, with\ud quadrupedalism, impaired intelligence, and dysarthric\ud speech. Their pedigree suggested an autosomal\ud recessive inheritance. MRI scans showed inferior\ud cerebellovermial and pontobulbar hypoplasia.\ud Case 1 did not display hypotonia, while case 2 had\ud been hypotonic for two years after birth. Case 2’s\ud hypotonia progressively disappeared, and at three\ud years old he started to sit, and could walk on all fours\ud by the age of four. Case 1 was quadrupedal for 20\ud years, and then walked upright with the aid of a\ud walking stick. Tendon reflexes were normal in case 1\ud but hyperactive in the lower extremities of case 2;\ud Babinsky was absent in case 1 but bilaterally present\ud in case 2. There was no nystagmus, no strabismus,\ud and no pes pedus in either case. Cognition was\ud severely impaired in both.\ud Conclusion: The emergence of quadrupedalism\ud during development, with a transition into bipedalism\ud in case 1, and the emergence of the quadrupedalism\ud after a full hypotonia and no locomotion in case 2,\ud were considered as examples of the processes of\ud adaptive self-organization, from the viewpoint of\ud dynamic systems theory

Constructing Abstraction Hierarchies Using a Skill-Symbol Loop

We describe a framework for building abstraction hierarchies whereby an agent alternates skill- and representation-acquisition phases to construct a sequence of increasingly abstract Markov decision processes. Our formulation builds on recent results showing that the appropriate abstract representation of a problem is specified by the agent's skills. We describe how such a hierarchy can be used for fast planning, and illustrate the construction of an appropriate hierarchy for the Taxi domain