To introduce traffic management schemes and traffic operation, influences on traffic flows should be estimated precisely. To this end, a traffic simulation model in urban road networks is proposed in this paper. That is an equilibrium traffic assignment model combined with estimation of junction delays. For each turning flows, junction delays are induced analytically as a function of flows and traffic signal control parameters. Traffic assignment uses an iterative procedure, and flow-delay curves are selected based on latest link flows. In this method, precise modeling of junction flows was enabled and simulation process was sharply promotea in etticiency compared with usual simulation model. Through an application to Kobe city, it was cleared that the model is useful for estimation oftraffic management schemes and traffic operation.

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The oxygen absorption of lake muds in a number of lakes in Japan, such as L. Takasuka, L. Kitaura, L. Tyûzenzi, etc., were determined by the author. Five grs. of fresh lake mud, whose oxygen content was desired, were placed in watre, then into a bottle of 280cc capacity, and then shaken vigorously 200 times and left to stand in a dark chamber for 4 hours. The decrease of the oxygen in the water was measured by Winklers standard method, following which the quantity of oxygen absorped by the humid muds at different temperatures were reduced to the equivalent .value of a dry sample of 1gr. at l5°C.
The horizontal and vertical distributions of oxygen absorption in lakes were studied from the limnological point of view, with the following results:
1) The horizontal distribution of oxygen absorption of lake muds in takes is controlled by the lake stream.
2) In non-stagnent lakes (S. Yoshimura's order II), there is an apparent relation between oxygen absorption of lake muds and depth, but there is no such relation in stagnent lakes (order III).
3) No relation, between oxygen absorption and coarse debris was observed in any lake type, although a positive relation was found between the O₂-absorption of lake muds and fine debris which, though evident in eutrophic lakes, is obscure in oligotrophies.
4) A linear relation between the O₂-acs. of lake muds an Loss Ignition was observed, the gradient of the line varying gradually with the fertility of the lake.
From these fact the author concludes that the oxygen absorbing capacity of lake muds depend upon its carbon contents.
5) In oligotrophic lakes, the influence of reduced substances, such as hydrogen sulfide, ferric iron, methane. etc., on the absorbing capacity of lake muds, is important.
6) From his experiments it seems that there is no relation between microorganisms and decomposition of lake muds.

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The purpose of this study is to clarify the usefulness concerning the survey in free descriptive answer style and the evaluation process to decide whether preferable or not, against the familiar regional landscapes recalled by the subjects. First of all, a questionnaire survey on preferable and dis-preferable landscapes in free descriptive answer style to the students of Hiroshima University as subjects was carried out. As for the analysis method of the answers, they were divided into three components, such as 'main object','condition of the object' and 'reason for the decision'. As a result of the survey, the fact that the subjects recalled not only the specific landscape elements, such as trees and buildings, but also the variety combination of landscape elements and whole image of landscapes was found out. In addition, the process of landscape evaluation was grasped by the fact that the relationships between each 'main object' and 'reason for the decision' have the feature which prompts to decide whether preferable or not. On the other hand, we clarified that 'main object' and 'reason for the decision' have the strong effect for separating the landscapes into two groups. However,'condition of the object' does not have such effect because it is the supplements for 'main object'.

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The purpose of this study is to clarify the characteristics of preference for regional landscape based on the analysis of physical characteristics, such as "Dimensions of landscape elements" and "Elements composition" on the photographs taken by the subjects according to their preference. At first, the subjects were required to take photographs that they prefer and dis-prefer through fieldwork in Higashi-Hiroshima City. As a result of the survey, 849 photographs of regional landscapes such as green, buildings, river, road and more were taken. According to the photographs, the relationship between the decision of "preferable or dis-preferable" and the physical characteristics of photographs was analyzed by the statistical technique. In addition, the effect on the evaluation of preference for regional landscapes based on the "Dimensions of landscape elements" and "Composition of elements" was clarified. Especially, when the dimensions of elements such as 'trees' and 'mountains' increase, the landscape is considered as preferable. According to this result, the dimensions of landscape elements affect the decision of preference. And, when the subjects recognize the object as complex composition, they show the tendency of decision as preferable landscape.

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