CERNのLEPは電子・陽電子の衝突型加速器で、1989年に運転が開始されたが、運転当初から、偏向電磁石の磁場の奇妙な変動に悩まされていた。1995年になって、この磁場変動は、

Battery-powered electric trains charge their batteries through collection of a large current from contact wires through their pantographs whilst at a standstill in stations. This current tends to be larger than that collected by normal trains when immobile in a station. Usually, current flowing through a contact wire causes an increase in the temperature of the contact wire. In the case of battery-powered electric trains, pantograph contact strips do not slide along the contact wire in non-electrified sections, allowing an oxide-like film to form on the contact wire depending on the number of days of exposure. The influence of this film on current collection is thought to be high, though this has not yet been evidenced. Consequently, the authors of this paper conducted exposure tests, measuring the thickness of the film on contact wires, contact-resistance, and numerically simulating thermal conduction, to unravel the unknowns surrounding influence of this film. This paper reveals the influence of the film and proposes a method and cycle for maintenance in the light of these experiment results.

そこで本研究では、スマートフォンと

調査の結果、乗車時間が短い場合は断片的な情報行動が多く、スマホから目を離すのは乗車後10分弱であった。立っている場合は車窓や車内広告を見るなど車内に目を向けやすいことも明らかになった。さらに、目的地の違いによっても情報行動が異なった。

これらの結果から、スマホと