273 research outputs found

    Multi-layered reasoning by means of conceptual fuzzy sets

    Get PDF
    The real world consists of a very large number of instances of events and continuous numeric values. On the other hand, people represent and process their knowledge in terms of abstracted concepts derived from generalization of these instances and numeric values. Logic based paradigms for knowledge representation use symbolic processing both for concept representation and inference. Their underlying assumption is that a concept can be defined precisely. However, as this assumption hardly holds for natural concepts, it follows that symbolic processing cannot deal with such concepts. Thus symbolic processing has essential problems from a practical point of view of applications in the real world. In contrast, fuzzy set theory can be viewed as a stronger and more practical notation than formal, logic based theories because it supports both symbolic processing and numeric processing, connecting the logic based world and the real world. In this paper, we propose multi-layered reasoning by using conceptual fuzzy sets (CFS). The general characteristics of CFS are discussed along with upper layer supervision and context dependent processing

    Adsorption of benzene derivatives on allophane

    Get PDF
    The adsorption properties of benzene derivatives from water on allophane, extracted from soil, have been investigated by UV and FTIR spectroscopic measurements. Allophane adsorbs benzoic acid, phthalic acid, benzaldehyde, ethyl benzoate, and diethyl phthalate. Benzoic acid, phthalic acid, and benzaldehyde formed carboxylate anions on the positive sites of the hydrated alumina surface of allophane. In the case of adsorption from an acidic solution (pH 2), a small amount of a neutral species of benzoic acid was detected on the allophane. Ethyl benzoate and diethyl phthalate were adsorbed by an interaction between their carbonyl groups and the hydroxyl groups of the allophane. It was confirmed that allophane has an adsorption ability for the benzene derivatives that are not only ionic but also polar molecules. Allophane was found to be available as an absorbent for use in water purification by a simple procedure.ArticleAPPLIED CLAY SCIENCE. 43(2):160-163 (2009)journal articl

    Non-volatile hybrid optical phase shifter driven by a ferroelectric transistor

    Full text link
    Optical phase shifters are essential elements in photonic integrated circuits (PICs) and function as a direct interface to program the PIC. Non-volatile phase shifters, which can retain information without a power supply, are highly desirable for low-power static operations. Here a non-volatile optical phase shifter is demonstrated by driving a III-V/Si hybrid metal-oxide-semiconductor (MOS) phase shifter with a ferroelectric field-effect transistor (FeFET) operating in the source follower mode. Owing to the various polarization states in the FeFET, multistate non-volatile phase shifts up to 1.25{\pi} are obtained with CMOS-compatible operation voltages and low switching energy up to 3.3 nJ. Furthermore, a crossbar array architecture is proposed to simplify the control of non-volatile phase shifters in large-scale PICs and its feasibility is verified by confirming the selective write-in operation of a targeted FeFET with a negligible disturbance to the others. This work paves the way for realizing large-scale non-volatile programmable PICs for emerging computing applications such as deep learning and quantum computing

    Crossover from coherent to incoherent scattering in spin-orbit dominated Sr2IrO4

    Full text link
    Strong spin-orbit interaction in the two dimensional compound Sr2IrO4 leads to the formation of Jeff=1/2 isospins with unprecedented dynamics. In Raman scattering a continuum attributed to double spin scattering is observed. With higher excitation energy of the incident Laser this signal crosses over to an incoherent background. The characteristic energy scale of this cross over is identical to that of intensity resonance effects in phonon scattering. It is related to exciton-like orbital excitations that are also evident in resonant X-Ray scattering. The crossover and evolution of incoherent excitations are proposed to be due to their coupling to spin excitations. This signals a spin-orbit induced entanglement of spin, lattice and charge degrees of freedoms in Sr2IrO4.Comment: 20 pages, 7 figure
    corecore