1,435 research outputs found

    SERKET: An Architecture for Connecting Stochastic Models to Realize a Large-Scale Cognitive Model

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    To realize human-like robot intelligence, a large-scale cognitive architecture is required for robots to understand the environment through a variety of sensors with which they are equipped. In this paper, we propose a novel framework named Serket that enables the construction of a large-scale generative model and its inference easily by connecting sub-modules to allow the robots to acquire various capabilities through interaction with their environments and others. We consider that large-scale cognitive models can be constructed by connecting smaller fundamental models hierarchically while maintaining their programmatic independence. Moreover, connected modules are dependent on each other, and parameters are required to be optimized as a whole. Conventionally, the equations for parameter estimation have to be derived and implemented depending on the models. However, it becomes harder to derive and implement those of a larger scale model. To solve these problems, in this paper, we propose a method for parameter estimation by communicating the minimal parameters between various modules while maintaining their programmatic independence. Therefore, Serket makes it easy to construct large-scale models and estimate their parameters via the connection of modules. Experimental results demonstrated that the model can be constructed by connecting modules, the parameters can be optimized as a whole, and they are comparable with the original models that we have proposed

    Novel fluorinated cyclic dienes and their chemistry

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    The work described in this thesis is concerned with three areas which are synthesis, nucleophilic reactions, and cycloaddition reactions of novel fluorinated cyclic dienes.1 Sodium amalgam has been investigated as an electromimetic medium to reduce various fluorinated alkenes. It has been found that this can act as a single electron transfer reagent and defluorinate a series of cyclic alkenes to yield their corresponding dienes in good yield and conversion. Tetrakis(dimethylamino) ethylene (TDAE) has also been found to be a suitable reagent. The chemistry of these dienes, in particular (A) and (B), is then discussed. A number of reactions with nucleophiles has been studied employing novel dienes (A) and (B). Basically vinylic fluorine has been replaced to yield a range of mono- or di-substituted products. Reactions of fluoride ion sources with (A) and (B) have been studied. Addition of fluoride ion sources to these dienes in a solvent forms their carbanionic intermediates. That of (A) is very unstable and reacts further with (A) to give its oligomers. However it can lead to the observable carbanion by reaction of the precursor of (A) with TDAE. On the other hand, the carbanionic ivintermediate of (B) is very stable, being observed by (^19)F-NMR. These carbanions have been characterised by various methods. 3 Numerous cycloaddition reactions have been attempted. Dienes (A) and(B) did not undergo Diels-Alder reaction as diene because of their extremely electron-deficient double bonds and their specific conformations. Diene (A) has reacted as a dienophile with hydrocarbon dienes to yield the corresponding cycloadducts. Addition of an excess of diazomethane to dienes (A) and (B) has given rise to 1,3-dipole cycloaddition reactions forming their corresponding diadducts, which have been identified as Δ(^2)-dihydropyrazole derivatives

    Forming Object Concept Using Bayesian Network

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    Symbol Emergence in Robotics: A Survey

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    Humans can learn the use of language through physical interaction with their environment and semiotic communication with other people. It is very important to obtain a computational understanding of how humans can form a symbol system and obtain semiotic skills through their autonomous mental development. Recently, many studies have been conducted on the construction of robotic systems and machine-learning methods that can learn the use of language through embodied multimodal interaction with their environment and other systems. Understanding human social interactions and developing a robot that can smoothly communicate with human users in the long term, requires an understanding of the dynamics of symbol systems and is crucially important. The embodied cognition and social interaction of participants gradually change a symbol system in a constructive manner. In this paper, we introduce a field of research called symbol emergence in robotics (SER). SER is a constructive approach towards an emergent symbol system. The emergent symbol system is socially self-organized through both semiotic communications and physical interactions with autonomous cognitive developmental agents, i.e., humans and developmental robots. Specifically, we describe some state-of-art research topics concerning SER, e.g., multimodal categorization, word discovery, and a double articulation analysis, that enable a robot to obtain words and their embodied meanings from raw sensory--motor information, including visual information, haptic information, auditory information, and acoustic speech signals, in a totally unsupervised manner. Finally, we suggest future directions of research in SER.Comment: submitted to Advanced Robotic

    The Suzaku Observations of SS Cygni in Quiescence and Outburst

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    We present results from the Suzaku observations of the dwarf nova SS Cyg in quiescence and outburst in 2005 November. Owing to high sensitivity of the HXD PIN detector and high spectral resolution of the XIS, we have determined parameters of the plasma with unprecedented precision. The maximum temperature of the plasma in quiescence 20.4 +4.0-2.6 (stat.) +/- 3.0 (sys.) keV is significantly higher than that in outburst 6.0 +0.2-1.3 keV. The elemental abundances are close to the solar ones for the medium-Z elements (Si, S, Ar) whereas they decline both in lighter and heavier elements. Those of oxygen and iron are 0.46 and 0.37 solar, respectively. That of carbon is exceptionally high and 2 solar at least. The solid angle of the reflector subtending over the optically thin thermal plasma is Omega/2\pi = 1.7+/-0.2 (stat.) +/-0.1 (sys.) in quiescence. A 6.4 keV iron Ka line is resolved into a narrow and broad components. These facts indicate that both the white dwarf and the accretion disk contribute to the continuum reflection and the 6.4 keV iron Ka line. We consider the standard optically thin boundary layer as the most plausible picture for the plasma configuration in quiescence. The solid angle of the reflector in outburst Omega/2\pi = 0.9 +0.5-0.4 and a broad 6.4 keV iron line indicates that the reflection in outburst originates from the accretion disk and an equatorial accretion belt. From the energy width of the 6.4 keV line, we consider the optically thin thermal plasma in outburst as being distributed on the accretion disk like solar coronae.Comment: 28 pages, 15 figures, accepted for publication in PASJ Suzaku 3rd special issue Pdf of this paper can be downloaded from http://www.astro.isas.jaxa.jp/~ishida/Papers/sscyg_sub2.pd

    Donor-Specific Anti-HLA Antibodies in Organ Transplantation: Transition from Serum DSA to Intra-Graft DSA

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    In the field of organ transplantation, donor-specific anti-HLA antibodies (DSA) have gained more popularity, as antibody-mediated rejection (AMR) has been recognized as an important factor to determine allograft survival. Thus, it is reasonable to believe that appropriate control of DSA is directly linked to well-managed immunosuppression, resulting in free from AMR. First, in order to prevent and manage AMR, it is of vital importance to be familiar with updated knowledge regarding crossmatch test and DSA detection methods, including intra-graft DSA. Second, it is also crucial to understand the standard criteria to diagnose AMR. Although pathological diagnosis and serum DSA (s-DSA) detection play the central role, the recent trend seems to be detection of intra-graft DSA (g-DSA). Third, regarding organ transplantation between sensitized pairs, the acceptable outcomes are obtained owing to recent preoperative desensitization protocols: depletion/modification of B cells, apheresis for antibodies, and inhibition of reaction between DSA and HLA. Finally, we would like to discuss the treatment of AMR. Further advances in diagnosis methods and emergences of effective treatments would be expected for acceptable control of AMR. In this chapter, we will review from the basics to recent topics in order to understand DSA and AMR
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