Masaki Ikeda

Person name disambiguation by bootstrapping

In this paper, we report our system that disambiguates person names in Web search results. The system uses named entities, compound key words, and URLs as features for document similarity calculation, which typically show high precision but low recall clustering results. We propose to use a two-stage clustering algorithm by bootstrapping to improve the low recall values, in which clustering results of the first stage are used to extract features used in the second stage clustering. Experimental results revealed that our algorithm yields better score than the best systems at the latest WePS workshop.

Two-Fermi-surface superconducting state and a nodal d-wave energy gap of the electron-doped Sm1.85Ce0.15CuO(4-δ) cuprate superconductor.

We report on laser-excited angle-resolved photoemission spectroscopy in the electron-doped cuprate Sm1.85Ce0.15CuO(4-δ). The data show the existence of a nodal hole-pocket Fermi surface both in the normal and superconducting states. We prove that its origin is long-range antiferromagnetism by an analysis of the coherence factors in the main and folded bands. This coexistence of long-range antiferrmagnetism and superconductivity implies that electron-doped cuprates are two-Fermi-surface superconductors. The measured superconducting gap in the nodal hole pocket is compatible with a d-wave symmetry.

A termite internal state model for elucidating caste differentiation

Eusocial insects form colony and adapt environmental fluctuations. Colony is maintained with caste differentiation, which is a self-organized task allocation. We researched termite caste differentiation. Termites have several specialized castes. The pseudergate, one of those, has some differentiation possibilities. It is suggested that juvenile hormone (JH) is concerned in termite caste differentiation. Our research emphasized focus on the relationship between the pseudergate caste differentiation and time evolution of JH titer. We built an termite internal state model through development for understanding of caste differentiation mechanism. This model was evaluated with mathematical analysis and computer simulation.