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Focusing of Timelike Geodesic Congruences in Gravitational Collapses : Derivation of the Fundamental System of Equations Describing Geometrical Perturbation Effects
No full textWe derive the fundamental system of equations describing modification in the focusing properties
of timelike geodesic congruences caused by the conformal perturbations in the spacetime geometry.
These new equations are expected to play the central role for the detailed understanding of
the final stage of gravitational collapses. The system of these equations is obtained by analyzing the
linear-responses to the conformal perturbations in the system of the Raychaudhuri-type equations.
We then apply it to the simplest model of the gravitational collapse, the time-reversed Friedmann-
Robertson-Walker model, and explicitly analyze the property of these equations. It turns out that
the focusing properties of geodesic congruences are much more sensitive to the detailed form of the
conformal perturbations than originally expected, so that the final stage of gravitational collapses
can be classified into several cases depending on the functional form of the conformal perturbations
言語活動を活性化する教師のインターベンションを支える「見とり」に関する研究
No full text(要旨)本論稿の目的は、学習者の言語活動を支える教師のコミュニケーションにおけるインターベン
ションを「日的」や「ゴール」を持った長期的で計画的な教授行為として捉え、豊かな知識や経験に裏
打ちされた教師の「見取り」が効果的なインターベンションを生み出す背景にあることを指摘すること
にある。このため、言語・非言語的側面から見とりの対象や視座を提示し、教師の「見取りの質」を向
上させるための知識や情報の獲得を研修によって促すこと、学習者理解の多角化、深化によって、学習
者個人や学習集団の特性を踏まえた「見取り」が行えるようになるための研修の構築を提案している
A Wandering Robot ： Self-localization and Mapping of Swarm Robots
No full textSwarm intelligence has been attracted much attention of researchers in various fields. A swarm robot is one of the
research fields of the swarm intelligence. In the study of the swarm robots, a number of small robots are used. Although
individual robot ability is not so high, a colony of robots can achieve a complex task with co-operative work. The ant
searches feeding area, and carries food to the nest with marking by pheromone. Other ants trace the pheromone and go
to the feeding area. Many ants shuttle between the nest and the feeding area. The pheromone route between the nest and
the feeding area is formed. Thus the route is confirmed and optimized. We focus on the swarm robot’s self-localization
and mapping in the exploration field
