With a view to develop a solar battery system for fishing boats, a long-tem experiment was conducted to evaluate the photo voltaic generating system with constant voltage control of the solar battery. The results showed that the output voltage of solar battery was always maintained constant. The ratio of solar radiation to electric power, i. e. efficiency was 11% on the average. However, the efficiency (Ef) during the experiment was a function of the mean temperature (Tm). An empirical equation was developed as follows. Ef = -0.0747　+　0.0162×Tm　-　3.24×10^-4　× Tm² These results lead to the conclusion that this system should be improved such that the efficiency is kept constant aｌｌ the time for a greater range of temperature.

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Transport processes of pelagic eggs and larvae of brown sole (Pleuronectes herzenseini) from the spawning ground near the Sado Strait in Sea of Japan were investigated using an Euler-Lagrangian numerical model. Since coastal currents under the wind influence and the interaction of vertical movement of eggs and larvae with the currents could have significant effects on the transport, numerical simulations using three types of wind conditions (north wind, west wind and west-south-west wind: the wind speed is 4m/s in each case.), two kinds of inflow condition (fast and slow), and two pattems of vertical movement (passive and active) were made to explore their influence on the transport process. The retention rate, which indicates the percentage of eggs and larvae retained in shelf areas shallower than 100m, ws calculated for each case. The retention rates under the westerly winds are appreciably high compared to those under the north wind. However, when the westerly wind speed is over 5m/s, the rates for the cases of passive movement rapidly decrease. On the other hand, the rates for the cases of active one are maintained as 100% even under the strong Winds, because the eggs and larvae tend to be transported along the shore line. This suggests that westerly winds, which are generally dominant during the spawning period of brown sole, could enhance the larval retention in the coastal water in combination with the vertical migration of larvae.

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It has been known that the dynamic response of rolling motions of small fishing vessels in the sea exhibits nonlinearities, because of some characteristics caused by the shapes of their bodies. This paper considers a methodology for applying a Neural Network model to the structure of the above response, and the effectiveness of forecasting the above rolling motions using this model. Comparisons of perfomances of forecasting between the method using a Neural Network model and a predictor of an autoregressive (AR) model suggested that it might be more effective to use a Neural Network model than to use an AR model. It means that the method for forecasting using a Neural Network model might be more reasonable to forecast the above roll motions than a linear forecasting method.

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1994-95年に2,000総トンの漁業練習船が行ったニュージランド・ハワイ航海において,各職種乗組員18名の歩行活動を計測し,それに及ぼす航海日数,海面状態に関する諸要因の影響を重回帰分析によって調べ,次の結果が得られた: (1)説明変数として重回帰式に取り入れられた変数名と,それらの偏回帰係数の符号だけに着目しても,得られた重回帰式の型は個人によって異なる。 (2)歩行活動の概要は航海日数,海域を表すダミー変数,午前午後の差を表すダミー変数によって決まり,海面状態(風向,風速,風浪,うねりの方向,高さおよび周期)は2次的な重要性しか持たない。 (3)重回帰式の多様性を含む得られた結果は,職務内容と関係が深いことがインタビューによって裏付けられた。

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The volcanic activities of Unzen. Fugen-dake had commenced in November 1990. The frequent large scale avalanche of earth and rocks in the volcanic activities had carried in a lot of fallen trees to Shimabara Bay. After these fallen trees had come in Shimabara Bay, Some of them were burried under volcanic ash near the mouth of Mizunasi river or drifted with the current, and brought a heavy damage to fishermen and sea-going ships. Research of the drift actual condition of floatage in Ariake Sea is'nt done, although current reseach have been rather extensively studied. Hence, the authors wish to present in this report the results of basic experiments. We made a mimic drift wood, and equipped it with GPS receiver. And we researched the actual condition of drift situation through the pIot of the mimic driftwood tracks, further apalyzed the wind effect which swayed the driftwood. We found that the driftwood pass through the Hayasaki strait during one or two ebb tide and arrive in Tachibana Bay. And when the wind speed is less than 9.7 knot, We found that drifting speed and direction of the mimic driftwood compared with the current speed and direction increased or decreased in 2-3 percent of each segment that we divided the wind vector in two direction. One direction is current direction and the other direction is a vertical segment to the current.

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波浪エネルギーを利用して海水交換を行うために砂浜に造成されたヒラメ稚魚の中間育成池において,流動と水質の変動特性を明らかにする唱的で現地観測を行った。測定項目は流速,水温,塩分,溶存酸素(DO)で,さらに流動パターンを把握するため染料拡散実験を実施した。 海水流入量は海水位と波高によって変動し,海水取入口から流入した海水は池内において循環流を形成して流出口に向かう。それゆえに水温とDOが最大値を示す時刻は場所によって異なることになる。DOに関しては海水取入口が閉じている状態では朝の6時に最低値の飽和度60%まで減少する。またDO収支から推定すると,池内におけるすべての消費過程を考慮したDO消費速度は0.162mg/l/hrとなった。そのうちの60%は水中懸濁物, 20%はヒラメの呼吸によるもので,残りは底質による消費であった。塩分収支から推定した海岸地下水流入量は海水流入量と比較すると無視できる程度であった。

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作用外力が浮体の図心に働き,浮体の回転運動が無視できる係留球体淳子の運動方程式の誘導と数値計算法について解説する。 1.球浮体の1点係留は球形礁体の中層浮魚礁が, 2. n連結球浮体の1点係留は海中多点計測機器係留が,そして3.連結球浮体の両端固定係留は延縄式ホタテ垂下養殖施設が具体例として挙げられる。付録の'BUOY-N'数値計算プログラムは'n達結球浮体の1点係留'のもので,計算機のディスプレイ上で波による浮体の運動を見ることができる。また,このプログラムを少し手直しすれば3. n連結球浮体の両端固定係留の計算も可能である。

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