Error estimates of the DtN finite element method for the exterior Helmholtz problem

AbstractA priori error estimates are established for the DtN (Dirichlet-to-Neumann) finite element method applied to the exterior Helmholtz problem. The error estimates include the effect of truncation of the DtN boundary condition as well as that of the finite element discretization. A property of the Hankel functions which plays an important role in the proof of the error estimates is introduced

Membranes for spontaneous separation of pedestrian counter flows

Designing efficient traffic lanes for pedestrians is a critical aspect of urban planning as walking remains the most common form of mobility among the increasingly diverse methods of transportation. Herein, we investigate pedestrian counter flows in a straight corridor, in which two groups of people are walking in opposite directions. We demonstrate, using a molecular dynamics approach applying the social force model, that a simple array of obstacles improves flow rates by producing flow separations even in crowded situations. We also report on a developed model describing the separation behavior that regards an array of obstacles as a membrane and induces spontaneous separation of pedestrians groups. When appropriately designed, those obstacles are fully capable of controlling the filtering direction so that pedestrians tend to keep moving to their left (or right) spontaneously. These results have the potential to provide useful guidelines for industrial designs aimed at improving ubiquitous human mobility.Comment: Manuscript accepted for publication in Europhysics Letter

Comprehensive Analysis of Risk Factors for Periodontitis Focusing on the Saliva Microbiome and Polymorphism

Few studies have exhaustively assessed relationships among polymorphisms, the microbiome, and periodontitis. The objective of the present study was to assess associations simultaneously among polymorphisms, the microbiome, and periodontitis. We used propensity score matching with a 1:1 ratio to select subjects, and then 22 individuals (mean age +/- standard deviation, 60.7 +/- 9.9 years) were analyzed. After saliva collection, V3-4 regions of the 16S rRNA gene were sequenced to investigate microbiome composition, alpha diversity (Shannon index, Simpson index, Chao1, and abundance-based coverage estimator) and beta diversity using principal coordinate analysis (PCoA) based on weighted and unweighted UniFrac distances. A total of 51 single-nucleotide polymorphisms (SNPs) related to periodontitis were identified. The frequencies of SNPs were collected from Genome-Wide Association Study data. The PCoA of unweighted UniFrac distance showed a significant difference between periodontitis and control groups (p 0.05). Two families (Lactobacillaceae and Desulfobulbaceae) and one species (Porphyromonas gingivalis) were observed only in the periodontitis group. No SNPs showed significant expression. These results suggest that periodontitis was related to the presence of P. gingivalis and the families Lactobacillaceae and Desulfobulbaceae but not SNPs

Triplet State Formation and Quenching Dynamics of 2-Mercaptobenzothiazole in Solution

An adduct-mediated triplet energy transfer from a triplet thione to an alkene is observed with time-resolved vibrational absorption spectroscopy.</p

Ambegaokar-Baratoff relations of Josephson critical current in heterojunctions with multi-gap superconductors

An extension of the Ambegaokar-Baratoff relation to a superconductor-insulator-superconductor (SIS) Josephson junction with multiple tunneling channels is derived. Appling the resultant relation to a SIS Josephson junction formed by an iron-based (five-band) and a single-band Bardeen-Cooper-Schrieffer (BCS) type superconductors, a theoretical bound of the Josephson critical current ($I_{\rm c}$) multiplied by the resistance of the junction ($R_{\rm n}$) is given. We reveal that such a bound is useful for identifying the pairing symmetry of iron-pnictide superconductors. One finds that if a measured value of $I_{\rm c}R_{\rm n}$ is smaller than the bound then the symmetry is $\pm s$-wave, and otherwise $s$-wave without any sign changes. In addition, we stress that temperature dependence of $I_{\rm c}R_{\rm n}$ is sensitive to the difference of the gap functions from the BCS type gap formula in the above heterojunction.Comment: 7 pages, 6 figure

Study on developing the teaching plan for ESD based on a coordination of a local government, NPO, and university: through the practicing the ESD program whose theme is the nature of the Setouchi-Sea.

本研究は，行政・ＮＰＯ・大学の三者が連携をしてＥＳＤを展開するための方法を，具体的な学習プログラムの開発を通して明らかにしていこうとするものである。新教育課程が実施されるようになって，ＥＳＤは学校の教育活動の柱の一つとして注目されるようになってきている。しかし，一部の先進的な学校を除いては，教師の間でＥＳＤが十分に理解されているとは言い難い現状が見られる。ＥＳＤについては行政やＮＰＯの活動の影響が大きく，それらの機関には実施のためのノウハウが蓄積されている。学校においてＥＳＤを効果的に展開するためには，それらの機関が持っている研究の成果を活用して行くことが重要であるが，そのためにこれらの機関をつなぐコーディネーターの役割を果たすのが大学ではないか。本研究では，学校と行政機関やＮＰＯの連携に基づくＥＳＤ実施の前提として，大学が行政やＮＰＯと連携していかにＥＳＤを実施していくかを，平成23年度に実施した取り組みを通して明らかにしていきたい