635 research outputs found

    STEENROD-ÄŚECH HOMOLOGY-COHOMOLOGY THEORIES ASSOCIATED WITH BIVARIANT FUNCTORS

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    Let NG0 denote the category of all pointed numerically generated spaces and continuous maps preserving base-points. In [SYH], we described a passage from bivariant functors NG0op × NG0 → NG0 to generalized homology and cohomology theories. In this paper, we construct a bivariant functor such that the associated cohomology is the Čech cohomology and the homology is the Steenrod homology (at least for compact metric spaces)

    Self-assembly of parallel atomic wires and periodic clusters of silicon on a vicinal Si(111) surface

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    Silicon self-assembly at step edges in the initial stage of homoepitaxial growth on a vicinal Si(111) surface is studied by scanning tunneling microscopy (STM). The resulting atomic structures change dramatically from a parallel array of 0.7 nm wide wires to one dimensionally aligned periodic clusters of the diameter ~ 2 nm and periodicity 2.7 nm in the very narrow range of growth temperatures between 400 and 300 C. These nanostructures are expected to play an important role in future development of silicon quantum computers. Mechanisms leading to such distinct structures are discussed.Comment: Accepted for publication in Phys. Rev. Lett. Numbers of pages and figures are 13 and 3, respectivel

    The shift from corporate punishment to psychotropic drugs : From interviews with staff at Children’s Home Y in Prefecture Z

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    This paper explores changes in the handling of problem behavior in children residing at children’s homes, particularly over the period of 1980-2000, from the perspective of medicalization (Conrad and Schneider 1992=2003). We chose Children’s Home Y, which exhibited advancement the administration of psychotropic drugs to children, for research purposes, conducting semi-structured interviews with eight staff members working at the facility. Our research revealed that a large number of delinquent children resided at Children’s Home Y through the 1980s, and that it was an everyday occurrence for staff to restrain violent children. By the 1990s, however, as corporal punishment became taboo as children’s rights came to the fore, this type of punishment was no longer acceptable. As of the early 2000s, specialized mental health staff have been assigned to children’s homes, while full-time psychiatrists are now assigned to child consultation centers. At this time it became easier for children with behavioral problems to be diagnosed as ADHD, and psychotropic drugs have clearly have been prescribed more frequently. Handling of behavioral problems in these children saw a major shift from corporate punishment to administration of psychotropic drugs, along with a trend toward medicalization. At the same time, interviews with staff indicated a certain degree of uneasiness with regard to the possibility over-medication, as well as concern over side effects of psychotropic drugs

    Structured Communication-Centered Programming for Web Services

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    This article relates two different paradigms of descriptions of communication behavior, one focusing on global message flows and another on end-point behaviors, using formal calculi based on session types. The global calculus, which originates from a Web service description language (W3C WS-CDL), describes an interaction scenario from a vantage viewpoint; the end-point calculus, an applied typed π -calculus, precisely identifies a local behavior of each participant. We explore a theory of end-point projection, by which we can map a global description to its end-point counterparts preserving types and dynamics. Three principles of well-structured description and the type structures play a fundamental role in the theory. </jats:p

    Petri Net Modeling for Ising Model Formulation in Quantum Annealing

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    Quantum annealing is an emerging new platform for combinatorial optimization, requiring an Ising model formulation for optimization problems. The formulation can be an essential obstacle to the permeation of this innovation into broad areas of everyday life. Our research is aimed at the proposal of a Petri net modeling approach for an Ising model formulation. Although the proposed method requires users to model their optimization problems with Petri nets, this process can be carried out in a relatively straightforward manner if we know the target problem and the simple Petri net modeling rules. With our method, the constraints and objective functions in the target optimization problems are represented as fundamental characteristics of Petri net models, extracted systematically from Petri net models, and then converted into binary quadratic nets, equivalent to Ising models. The proposed method can drastically reduce the difficulty of the Ising model formulation
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