Rhythm Patterns Interaction - Synchronization Behavior for Human-Robot Joint Action

Interactive behavior among humans is governed by the dynamics of movement synchronization in a variety of repetitive tasks. This requires the interaction partners to perform for example rhythmic limb swinging or even goal-directed arm movements. Inspired by that essential feature of human interaction, we present a novel concept and design methodology to synthesize goal-directed synchronization behavior for robotic agents in repetitive joint action tasks. The agents’ tasks are described by closed movement trajectories and interpreted as limit cycles, for which instantaneous phase variables are derived based on oscillator theory. Events segmenting the trajectories into multiple primitives are introduced as anchoring points for enhanced synchronization modes. Utilizing both continuous phases and discrete events in a unifying view, we design a continuous dynamical process synchronizing the derived modes. Inverse to the derivation of phases, we also address the generation of goal-directed movements from the behavioral dynamics. The developed concept is implemented to an anthropomorphic robot. For evaluation of the concept an experiment is designed and conducted in which the robot performs a prototypical pick-and-place task jointly with human partners. The effectiveness of the designed behavior is successfully evidenced by objective measures of phase and event synchronization. Feedback gathered from the participants of our exploratory study suggests a subjectively pleasant sense of interaction created by the interactive behavior. The results highlight potential applications of the synchronization concept both in motor coordination among robotic agents and in enhanced social interaction between humanoid agents and humans.     

An Efficient Two-Tier Causal Protocol for Mobile Distributed Systems

Causal ordering is a useful tool for mobile distributed systems (MDS) to reduce the non-determinism induced by three main aspects: host mobility, asynchronous execution, and unpredictable communication delays. Several causal protocols for MDS exist. Most of them, in order to reduce the overhead and the computational cost over wireless channels and mobile hosts (MH), ensure causal ordering at and according to the causal view of the Base Stations. Nevertheless, these protocols introduce certain disadvantage, such as unnecessary inhibition at the delivery of messages. In this paper, we present an efficient causal protocol for groupware that satisfies the MDS''s constraints, avoiding unnecessary inhibitions and ensuring the causal delivery based on the view of the MHs. One interesting aspect of our protocol is that it dynamically adapts the causal information attached to each message based on the number of messages with immediate dependency relation, and this is not directly proportional to the number of MHs.     

Synthesis and Calibration of Phosphorescent Nanoprobes for Oxygen Imaging in Biological Systems

Oxygen measurement by phosphorescence quenching [1, 2] consists of the following steps: 1) the probe is delivered into the medium of interest (e.g. blood or interstitial fluid); 2) the object is illuminated with light of appropriate wavelength in order to excite the probe into its triplet state; 3) the emitted phosphorescence is collected, and its time course is analyzed to yield the phosphorescence lifetime, which is converted into the oxygen concentration (or partial pressure, pO₂). The probe must not interact with the biological environment and in some cases to be 4) excreted from the medium upon the measurement completion. Each of these steps imposes requirements on the molecular design of the phosphorescent probes, which constitute the only invasive component of the measurement protocol. Here we review the design of dendritic phosphorescent nanosensors for oxygen measurements in biological systems. The probes consist of Pt or Pd porphyrin-based polyarylglycine (AG) dendrimers, modified peripherally with polyethylene glycol (PEG''s) residues. For effective two-photon excitation, termini of the dendrimers may be modified with two-photon antenna chromophores, which capture the excitation energy and channel it to the triplet cores of the probes via intramolecular FRET (Förster Resonance Energy Transfer). We describe the key photophysical properties of the probes and present detailed calibration protocols.Download video file.^{(126M, mp4)}     

GEMS: Gossip-Enabled Monitoring Service for Scalable Heterogeneous Distributed Systems

Gossip protocols have proven to be effective means by which failures can be detected in large, distributed systems in an asynchronous manner without the limitations associated with reliable multicasting for group communications. In this paper, we discuss the development and features of a Gossip-Enabled Monitoring Service (GEMS), a highly responsive and scalable resource monitoring service, to monitor health and performance information in heterogeneous distributed systems. GEMS has many novel and essential features such as detection of network partitions and dynamic insertion of new nodes into the service. Easily extensible, GEMS also incorporates facilities for distributing arbitrary system and application-specific data. We present experiments and analytical projections demonstrating scalability, fast response times and low resource utilization requirements, making GEMS a potent solution for resource monitoring in distributed computing.     

一类具有两个可变参数的Willis环脑动脉瘤系统的自适应同步控制

基于李雅普诺夫稳定性理论,设计自适应控制器,讨论了两个可变参数的Willis环上脑动脉瘤混沌系统的同步问题.对可变参数采用自适应调节,在该控制器的作用下实现了两个参数不相同的Willis环上脑动脉瘤混沌系统的同步.数值仿真结果验证了此设计的有效性.     

Emergent Bioanalogous Properties of Blockchain-based Distributed Systems

Origins of Life and Evolution of Biospheres - We apply a novel definition of biological systems to a series of reproducible observations on a blockchain-based distributed virtual machine (dVM). We...     

Complex Generalized Synchronization and Parameter Identification of Nonidentical Nonlinear Complex Systems

In this paper, generalized synchronization (GS) is extended from real space to complex space, resulting in a new synchronization scheme, complex generalized synchronization (CGS). Based on Lyapunov stability theory, an adaptive controller and parameter update laws are designed to realize CGS and parameter identification of two nonidentical chaotic (hyperchaotic) complex systems with respect to a given complex map vector. This scheme is applied to synchronize a memristor-based hyperchaotic complex Lü system and a memristor-based chaotic complex Lorenz system, a chaotic complex Chen system and a memristor-based chaotic complex Lorenz system, as well as a memristor-based hyperchaotic complex Lü system and a chaotic complex Lü system with fully unknown parameters. The corresponding numerical simulations illustrate the feasibility and effectiveness of the proposed scheme.     

Theta Synchronization of Phonatory and Articulatory Systems in Marmoset Monkey Vocal Production

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Distributed Shared Arrays: Portable Shared-Memory Programming Interface for Multiple Computer Systems

This paper describes the design and implementation of a parallel programming environment called Distributed Shared Array (DSA), which provides a shared global array abstract across different machines connected by a network. In DSA, users can define and use global arrays that can be accessed uniformly from any machines in the network. Explicit management of array area allocation, replication, and migration is achieved by explicit calls for array manipulation: defining array regions, reading and writing array regions, synchronization, and control of replication and migration. The DSA is integrated with Grid (Globus) services. This paper also describes the use of our model for gene cluster analysis, multiple alignment and molecular dynamics simulation. In these applications, global arrays are used for storing the distance matrix, alignment matrix and atom coordinates, respectively. Large array areas, which cannot be stored in the memory of individual machines, are made available by the DSA. Scalable performance of DSA was obtained compared to that of conventional parallel programs written in MPI.     

Joint Frequencies of Alleles Determined by Separate Formulations for the Mating and Mutation Systems

A method to calculate joint gene frequencies, which are the probabilities that two neutral genes taken at random from a population have certain allelic states, is developed taking into account the effects of the mating system and the mutation scheme. We assume that the mutation rates are constant in the population and that the mating system does not depend on allelic states. Under either--the condition that mutation rates are symmetric or that the mating unit is large and the mutation rate is small--the general formula is represented by two terms, one for the mating system and the other for the mutation scheme. The term for the mating system is expressed using the coancestry coefficient in the infinite allele model, and the term for the mutation scheme is a function of the eigenvalues and the eigenvectors of the mutation matrix. Several examples are presented as applications of the method, including homozygosity in a stepping-stone model with a symmetric mutation scheme.     

Divisible Load Theory: A New Paradigm for Load Scheduling in Distributed Systems

Divisible load theory is a methodology involving the linear and continuous modeling of partitionable computation and communication loads for parallel processing. It adequately represents an important class of problems with applications in parallel and distributed system scheduling, various types of data processing, scientific and engineering computation, and sensor networks. Solutions are surprisingly tractable. Research in this area over the past decade is described.     

Integrating electron microscopy information into existing Distributed Annotation Systems

The increase of daily released bioinformatic data has generated new ways of organising and disseminating information. Specifically, in the field of sequence data, many efforts have been made not only to store information in databases, but also to annotate it and then share these annotations through a standard XML (eXtensible Markup Language) protocol and appropriate integration clients. This is the context in which the Distributed Annotation System (DAS) has emerged in genomics. Additionally, initiatives in the field of structural data, such as the extension of DAS to atomic resolution data, which generated the SPICE client, have also occurred. This paper presents 3D-EM DAS, a further extension of the DAS protocol that allows sharing annotations about hybrid models. This annotation system has been built on the basis of the EMDB, which stores Three-dimensional Electron Microscopy (3D-EM) volumes, PDB, which houses atomic coordinates, and UniProt (for protein sequences) databases. In this way, annotations for sequences, atomic coordinates, and 3D-EM volumes are collected and displayed through a single graphical visualization client. Thus, users have an integrated view of all the annotations together with the whole macromolecule (3D-EM map coming from EMDB), the atomic resolution structures fitted into it (coordinates coming from PDB) and the sequences corresponding to each of the structures (from UniProt).     

Doubly Optimized Calibrated Support Vector Machine (DOC-SVM): An Algorithm for Joint Optimization of Discrimination and Calibration

Historically, probabilistic models for decision support have focused on discrimination, e.g., minimizing the ranking error of predicted outcomes. Unfortunately, these models ignore another important aspect, calibration, which indicates the magnitude of correctness of model predictions. Using discrimination and calibration simultaneously can be helpful for many clinical decisions. We investigated tradeoffs between these goals, and developed a unified maximum-margin method to handle them jointly. Our approach called, Doubly Optimized Calibrated Support Vector Machine (DOC-SVM), concurrently optimizes two loss functions: the ridge regression loss and the hinge loss. Experiments using three breast cancer gene-expression datasets (i.e., {"type":"entrez-geo","attrs":{"text":"GSE2034","term_id":"2034"}}GSE2034, {"type":"entrez-geo","attrs":{"text":"GSE2990","term_id":"2990"}}GSE2990, and Chanrion''s datasets) showed that our model generated more calibrated outputs when compared to other state-of-the-art models like Support Vector Machine ( = 0.03,  = 0.13, and <0.001) and Logistic Regression ( = 0.006,  = 0.008, and <0.001). DOC-SVM also demonstrated better discrimination (i.e., higher AUCs) when compared to Support Vector Machine ( = 0.38,  = 0.29, and  = 0.047) and Logistic Regression ( = 0.38,  = 0.04, and <0.0001). DOC-SVM produced a model that was better calibrated without sacrificing discrimination, and hence may be helpful in clinical decision making.     

Deubiquitinating Enzymes in Model Systems and Therapy: Redundancy and Compensation Have Implications

The multiplicity of deubiquitinating enzymes (DUBs) encoded by vertebrate genomes is partly attributable to whole genome duplication events that occurred early in chordate evolution. By surveying the literature for the largest family of DUBs (the ubiquitin‐specific proteases), extensive functional redundancy for duplicated genes has been confirmed as opposed to singletons. Dramatically conflicting results have been reported for loss of function studies conducted through RNA interference as opposed to inactivating mutations, but the contradictory findings can be reconciled by a recently proposed compensatory mechanism involving nonsense‐mediated RNA degradation. Duplicated genes are often inactivated to become pseudogenes, and it is proposed that such is the fate of the USP15 gene of zebrafish, a commonly used model system. As it is reviewed here, these observations have implications not only for the interpretation of model system phenotypes but also for therapeutic interventions designed to target DUBs.     

Performance Evaluation of the Deadline Credit Scheduling Algorithm for Soft-Real-Time Applications in Distributed Video-on-Demand Systems

Video-on-Demand (VoD) systems are expected to support a variety of multimedia services to the users, such as tele-education, teleconference, remote working, videotelephony, high-definition TV, etc. These applications necessitate abundant bandwidth and buffer space as well as appropriate software and hardware for the efficient manipulation of the networks resources. In this work we investigate a promising scheduling algorithm referred to as the Deadline Credit (DC) algorithm, which exploits the available bandwidth and buffer space to serve a diverse class of prerecorded video applications. We provide simulation results when the DC algorithm is applied to a hierarchical architecture distributed VoD network, which fits the existing tree topology used in todays cable TV systems. The issues investigated via the simulations are: the system utilization, the influence of the buffer space on the delivered Quality of Service, and the fairness of the scheduling mechanism. We examine cases with homogenous as well as diverse video streams, and extend our system to support interactive VCR-like functions. We also contribute a modification to the DC algorithm so that in cases when the video applications have different displaying periods, the video streams obtain a fair share of the networks resources. Finally, we validate our results by simulating actual videos encoded in MPEG-4 and H.263 formats.     

植物受动物采食后的补偿作用──影响补偿作用的因素

植物受动物采食后的补偿作用影响补偿作用的因素原保忠王静赵松岭（兰州大学干旱农业生态国家重点实验室,７３００００）ＰｌａｎｔＣｏｍｐｅｎｓａｔｉｏｎｆｏｒＡｎｉｍａｌＨｅｒｂｉｖｏｒｙＦａｃｔｏｒｓＡｆｅｃｔｉｎｇＰｌａｎｔＣｏｍｐｅｎｓａｔｉｏｎ．Ｙ...