1,044 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

    Approximate Spin Projection for Broken-Symmetry Method and Its Application

    Get PDF
    A broken-(spin) symmetry (BS) method is now widely used for systems that involve (quasi) degenerated frontier orbitals because of their lower cost of computation. The BS method splits up-spin and down-spin electrons into two different special orbitals, so that a singlet spin state of the degenerate system is expressed as a singlet biradical. In the BS solution, therefore, the spin symmetry is no longer retained. Due to such spin-symmetry breaking, the BS method often suffers from a serious problem called a spin contamination error, so that one must eliminate the error by some kind of projection method. An approximate spin projection (AP) method, which is one of the spin projection procedures, can eliminate the error from the BS solutions by assuming the Heisenberg model and can recover the spin symmetry. In this chapter, we illustrate a theoretical background of the BS and AP methods, followed by some examples of their applications, especially for calculations of the exchange interaction and for the geometry optimizations

    Density wave instability in a 2D dipolar Fermi gas

    Get PDF
    We consider a uniform dipolar Fermi gas in two-dimensions (2D) where the dipole moments of fermions are aligned by an orientable external field. We obtain the ground state of the gas in Hartree-Fock approximation and investigate RPA stability against density fluctuations of finite momentum. It is shown that the density wave instability takes place in a broad region where the system is stable against collapse. We also find that the critical temperature can be a significant fraction of Fermi temperature for a realistic system of polar molecules.Comment: 10 figure

    Photosynthetic characteristics of phytoplankton off Adelie Land, Antarctica, during the austral summer

    Get PDF
    The photosynthesis-irradiance characteristics (P-E curves) and quantum yields of natural phytoplankton were investigated in the Southern Ocean off Adelie Land, Antarctica, during the austral summer. Data were acquired at eight stations during a cruise of T/V Umitaka-Maru III. The photosynthetic P-E curves showed low light adaptation of phytoplankton. Mean value (±standard deviation) of the P-E curve parameters, α^*, and I_k, were 0.014 (±0.013) mgC (mg chl. α)^ h^1 (μmol photons m^ s^)^ and 76 (±55) μmol photons m^ s^, respectively. Although phytoplankton were adapted to low irradiance, the phytoplankton in the SCM were not fully adapted to the low irradiance prevailing at those depths. P^*_ in the studied region was low (mean of 0.66 (±0.37) mgC (mg chl. α)^ h^) and generally lower than the previously reported values in waters near the Antarctic Peninsula. The maximum quantum yield varied widely, ranging from 0.001 to 0.038mol C (mol photons absorbed)^ at the surface and from 0.007 to 0.092mol C (mol photons absorbed)^ near the bottom of the euphotic zone. These values were within the range of published data. Comparison of photosynthetic parameters with historical data indicated that primary productivity from remotely sensed data for the whole of the Southern Ocean, based on these field estimates of photosynthetic parameters, has been overestimated

    A Qualitative Study on The Function of Information and Communication Technology Utilization in Teaching Students with Intellectual Disabilities: Implications for Techniques of Teaching/Job Coaching

    Get PDF
    Background: Recently, the use of Information and Communication Technology (ICT) in education has been promoted in Japan. However, teachers do not yet fully understand using ICT for persons with intellectual disabilities. Objective: This study clarifies the support functions of ICT as perceived by teachers involved in special needs education (support for students with intellectual disabilities). Methods: We conducted in-depth interviews with five teachers involved in special-needs education. We qualitatively analyzed the interview data obtained using content analysis. Results: From the interviews, 53 ICT-utilization episodes were obtained. These episodes were categorized into 13 categories of utilization and seven aspects of support: understanding, communication, behavior, meta-cognition, environment, memory, and opportunities. Conclusion: ICT is a beneficial tool to compensate for intellectual disabilities and help students with intellectual disabilities learn better. We believe that teachers can better assist students with intellectual disabilities by successfully matching individual needs with the ICT features. The results obtained in this study will be helpful while considering support for persons with intellectual disabilities, not only in education but also in vocational training, employment support, and telework support for persons with intellectual disabilities

    Characteristics of the summer decapod larvae community through Bering and Chukchi Seas

    Get PDF
    第6回極域科学シンポジウム分野横断セッション:[IA] 急変する北極気候システム及びその全球的な影響の総合的解明―GRENE北極気候変動研究事業研究成果報告2015―11月19日(木) 国立極地研究所1階交流アトリウ

    <ARTICLE>Study of the Fishery in the Nishiura District

    Get PDF
    corecore