The method to obtain the position of the measurement point by a single satellite applies to the distress
rescue and the oceanic observation.
The present study analyzed the improvement of the positioning accuracy by the improvement of this positioning
method. The analysis was carried out by means of the numerical simulation. The positioning calculation
was carried out using the data of intervals of one minute when a satellite approached the measurement point.
As a result, When the angle of elevation of the satellite was 80 degrees or less, the positioning error became
about 0.2 nm (nautical mile) in the latitudinal direction and about 0.5 nm in the longitudinal direction. This is a
remarkable improvement on the accuracy of the usual positioning method.
We completed the technique to constantly produce the artificial seeds of the short neck clam Ruditapes
philippinarum in large scale, because its natural resources have seriously been decreased in Japan. In Yanaguchi
Prefecture 107 seeds of 1-2mm in shell size have been able to obtain in a 100 m3 tank from 1992, and about 2 × 107 seeds were produced annually. For incresing the survival rate of the released seeds, the intermediate culture of them unti1 10mm in shell size was carried out mainly by Yamaguchi Prefectural Fisheries Station and ten Fisheries Cooperative Associations. The large scale seed production of this clam and its intermediate culture are described in detail.
We, furthermore, present the results on the production of the seeds bearing a special color pattem on the
shell as a marker of the released seeds. Bp (banded purple) type shell, Which is very rare in the fields, could be
fixed genetically by the group and individual inbreedings. In 1996 we obtained the fourth generation of the Bp
type shell at the rate of 92.5 % in the group inbreeding experiments and nearly 100 % in the individual inbreeding
experiments. A pert of them were released to the fields after the intermediate culure.
It is known that verical vortices of various sizes distribute in the sea and those vortexes are closely comected
With vertical circulation of sea water and the matter diffusion of the bottom in deep sea from the latest marine
observation and the numerical analysis.
This paper shows the numerical method of the two types rotating flows based on the Navier-Stokes momentum
equation, and estimates the velocity intensity in the bottom boundary layer and shows that the upwelling depends
on the those results.