本州四国連絡橋は、平日においては日常交通に利用されるのための生活橋として、休日においては広域的な周遊などに利用されるとしての役割の増加が期待されている。この役割の変化の分析にはアンケート調査が適しているが、費用などの問題がある。一方、本四架橋内の交通量は日ごとに計測されているものの、有効に活用されているとはいえない。
本論文では、本四架橋の日交通量を分析することで交通量および架橋同士の相互作用の変化を明らかにすることを目的とした。その結果、交通量はカレンダー情報により大きく影響を受け、また架橋間には特に東西間をまたぐような周遊行動が発生していることが明らかとなった。さらに、これらの特徴は経年的に変化していることが明らかとなった。

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In Okazaki City, Aichi Prefecture, the four hundred fiftieth anniversary of Ieyasu TOKUGAWA was accomplished in 1992. Corresponding to the event, some arrangements of Okazaki Park have proceeded, which exists in the area surrounded by the River Yahagi's tributaries, where was once the site of Okazaki Castle alias Ryuugajo. As one of arrangements, the aged bridges around the park have improved or reconstructed. It is regrettable, however, a new bridge was reconstruted of iron instead of attractive stones even if it had a short span. It is general that wooden or stone bridges are familiar and attractive to the region roundabout, and they have their own history. The tendency are observed not only in Okazaki City but also all over our country. It has resulted from the reason that the demand for structural safety, fire preventability and durability knock down the one for design quality and historical merit. It is not too much to say that the high economic growth has produced the phenomenon. Recently, environmental problem, landscape problem and problems of historic building's restoration and preservation have been understood by the public, then it is necessary for bridges to concider these problems. In this paper, from the viewpoint of mentioned above, the changes of bridges around Okazaki Park are concidered and a model plan for reconstrution of the aged Shinkyou (bridge built across the pond that was once moat of the castle) is presented.

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1. Roost distribution, feeding dispersal and density and behaviour of feeding flocks before roosting flight in the Grey Starling, Sturnus cineraceus, were studied in Kanto Plain from 1953 to 1962. This paper describes the results of some 45 winter observations. The roost distribution will be further iuvestigated.
2. In Kanto Plain, extensive feeding range of big Koshigaya roost (about 50, 000 birds) north of Tokyo occupies 30-40km radius circle of the plain. Other smaller roosts are situated outside of this feeding range.
3. Daytime (late afternoon observation) feeding flocks usually consisted of several to 30, sometimes 100 birds and each flock was more or less 500m apart. This spacing by small flocks should be a response to the food availability which are minute mud fauna and rather sparcely distributed larger larvae, etc.
4. In feeding ground assembly towards evening, up to 300, rarely 500 or exceptionally 1, 000 birds gathered into a flock, the average flock size being 176 birds. Thus an area where a flock of over 150 birds was found could be regarded as a good feeding place. Evening flocks gradually moved always towards the direction of main roost (to which most of the flock members belonged). The distance of this late afternoon movement to final gathering place was usually 1.5-2.0km.
5.The density, the economic density, of daytime feeding flocks in the field was 30-500 (average 160) birds per 1km², therefore 0.3-5.0 (average 1.6) birds per 1 ha, which coincided with previously calculated data. This may suggest that a space of about 1 ha is wanted by one starling.
6. Two types of feeding dispersal from a roost were noticed. In type A, the flock size decreased with greater distance along a certain direction and under similar conditions of the feeding environment (see NNW direction in the map). In type B, concentration to a certain feeding area was found. A remarkable concentration was at 40km from the roost which was about the maximum distance of feeding dispersal. On this feeding flight line, the size of feeding flocks decreased with shorter distance from the roost, i. e. greater flock size towards the concentration area. This concentration was possibly due to higher food resources plus good breeding envirnment (old trees with holes).
7. The middle area on the B type dispersal line was apparently occupied by a big feeding flock of another roost (confirmed by roosting flight direction). If this were a competitve segregation of feeding grounds by two different roost-flocks, it is a remarkable instance.
8. It commonly happens that at the peripheral feeding area, the feeding flocks make a joint flock with birds of other roost or roosts. Thus on starting for roosting flight they take off to different, or to each determined, directions.
9. Distribution and observation data at eleven roosts in the study asea (see fig. 1) are described.

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地学教育において，経済性，安全性等の理由で地質巡検の実施はますます困難になっている．遠隔地を仮想的に閲覧できるVR技術は巡検を仮想的に再現できる可能性があるが，視点位置が固定されており，当地を歩き回ることはできず，実巡検と大きな乖離がある．そこで筆者らは，視点の平行移動が可能なVR教材を開発し，地学の初学者を対象に効果を検証した．その結果，本VR教材は，実巡検を再現し補完できる可能性が示された．

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