米国式旋網船について-1 : 鮪延縄船との比較

The American style purse seiner developed in the United States was studied in comparision with the tuna long liner developed in Japan, in terms of principal particulars, speed, hull form and conditions expressed in mean value of four vessels each. In comparison with the tuna long liner of 500 GT class, the American style purse seiner of the same size is 20.2% broader in actual size and 16% broader in L/B and has more stability. The speed which is required to be over 14 knots in cruising condition is 14.7 knots for the purse seiner and 12.8 knots for the tuna long liner. The purse seiner has the hull form of greater midship section coefficient and smaller block coefficient, i.e., the hull form of fat midship and rapidly slim bow and stern. The incident angle of water line at the bow is 9～14 degrees for the purse seiner while it is approximately 38 degrees for the tuna long liner. The trim of the purse seiner in light load condition is by the head since this vessel carries net and skiff boat in the stern area. This is a significant characteristic of the purse seiner. The metacentric height (GM) in full load condition, i.e., in working condition is 0.93m which is about twice as much as that of ordinary fishing vessels, giving consideration to the safty against unvavorable condition in navigation and fishing operation. However, the period of rolling is 7～9 seconds which is an ordinary period for the fishing vessel of 500 GT class.米国で開発された500総トン級米国式旋網船と日本で開発された500総トン級鮪延縄船各4隻の要目,速力、船型,性能の平均値を比較検討した。米国式旋網船は,甲板上の搭載物重量が重いため幅を鮪延縄船より20.2%広げて復原力を増している。米国式旋網船の巡航速力である3/4負荷では,14ノット以上要求されているが,調査した限りでは平均で14.7ノットであり,鮪延縄船では,12,8ノットであった。米国式旋網船は,船体中央部では鮪延縄船より肥っているが船首および船尾で急激にやせている船型である。船首の水線入射角は,米国式旋網船は極端に小さく9度～14度であり,鮪延縄船では38度位である。軽荷状態の米国式旋網船のTrimはTrim by the headである。船尾に重量物(漁網約30トン,9mスキフボート約15トン)を積む関係であるが,このTrimは顕著な特徴である。重量物の搭載後の満載状態では1.14mTrim by the sternとなり,航海に適したTrimとなる。運航者が,船の安全度と初期復原力を知る目安としているMetacentric height (GM)は,稼働状態の満載状態では0.93mで一般漁船の約2倍となっているが,漁撈時に於ける船体の傾斜,その他の航海,操業時における悪条件の中での安全性について考慮を払ったものと思われる。GMが大きければ横揺れ周期が短くなるが,周期は7～9秒で500トン級漁船としては通常の周期である

米国式旋網船について-2 : 船尾トロ-ル船との比較

The American style purse seiner of 500 GT class was studied in comparision with the stern trawler of 500 GT class originally developed in England and improved and established in Japan, in terms of principal particulars and other items expressed in mean value of four vessels each as the previous paper. The American style purse seiner is 15.8 % broader in actual size than the stern trawler and 12% broder in L/B. The cruising speed of the purse seiner at 3/4 load of full load condition is 14,7 knots which is faster than the stern trawler by 2.8 knots. The purse seiner has the hull form of greater midship section coefficient and smaller block coefficient, i.e., the hull form of fat midship and slim bow and stern together with a fine streamline shape of the bottom in front of the propeller and the broad stern deck. As to the motion characteristics of the purse seiner in longitudinal wave, the relative pitching of the bow against the wave surface shows a 20～30% greater amplitude when synchronized with the severest head sea as compared with the conventional avarage Japanese fishing vessels. However, since consideration has been given to the height of the bow freeboard and to the increase of flaring, the splash of waves from the bow may not be particularly strong.米国で開発された500総トン級米国式旋網船と英国で開発され日本で改良固定された500総トン級船尾トロール船各4隻の諸要目,速力,船型,性能の平均値を比較検討した。米国式旋網船は船尾トロール船より巾が15.8%広い。平均速力は,巡航速力(3/4負荷)における米国式旋網船が2.8ノット速い14.7ノットであり,抵抗試験によれば米国式旋網船は現存の肥大船型に比べて推進馬力が半分以下でも同一速力が出せる燃料節減船型である事が推定されている。船型は,船体中央部が旋網船が肥っており船首尾でやせており,プロペラ前方の船底部分がきれいな流線型となっている。旋網船の縦波中の運動特性は,船首の波面に対する相対上下揺振を在来の平均的日本漁船と比べると最もきびしい向い波同調状態時において20～30%程度の振巾増加が見られるが,船首乾舷の高さとフレアーの増大が考慮されているので船首からの波浪打ち込みが特に激しくなる事は無いと考えられる

Tuning of a fuzzy classifier derived from data

AbstractIn our previous work we developed a method for extracting fuzzy rules directly from numerical data for pattern classification. The performance of the fuzzy classifier developed using this methodology was comparable to the average performance of neural networks. In this paper, we further develop two methods, a least squares method and an iterative method, for tuning the sensitivity parameters of fuzzy membership functions by which the generalization ability of the classifier is improved. We evaluate our methods using the Fisher iris data and data for numeral recognition of vehicle license plates. The results show that when the tuned sensitivity parameters are applied, the recognition rates are improved to the extent that performance is comparable to or better than the maximum performance obtained by neural networks, but with shorter computational time

Strain Hardening and Recovery in High-Temperature Deformation by Pure-Metal Mode

By a new method using the stress relaxation test, the coefficient of strain hardening without recovery (h) and the rate of recovery without strain hardening (r) are estimated in high-temperature deformation of fcc aluminum and b c c iron, where the internal stress is confirmed to be nearly 100% of the flow stress. Both h and r are dependent on applied stress σ and temperature T in a steady-state deformation, and are represented by h=h_0(σ/E)^m exp(-Q_h/RT) and r=r_0 (σ/E)^l exp (-Q_r/RT), where h_0 and r_0 are constants, E is Young\u27s modulus and m=-0.88(-1.5), l=4.3(3.2), Q_h=-22(-76) kJ/mol, Q_r=88(132) kJ/mol for aluminum(iron). During a transient state of tensile deformation in the constant strain-rate test, h and r are nearly independent of strain. The activation energy for recovery (Q_r) is found to be appreciably smaller than that of self-diffusion, and then possible roles of pipe-diffusion and strain-enhanced diffusion in dynamic recovery are discussed

Morphological and molecular phylogenetic studies of a red alga, Halymenia durvillei, (Halymeniaceae, Halymeniales) from Indo-Pacific

Morphological and molecular phylogenetic studies were made on recently collected Halymenia plants widely from Japan, the Philippines, Indonesia, Malaysia and Thailand. Although the external morphology (branching pattern, blade width, or degree of dentation) was very variable, no special differences were found in their vegetative and reproductive structures. The features are close to Halymenia durvillei. Our rbcL gene sequence analysis has shown that the branched Halymenia plants are all included in a distinct, monophyletic clade, separate from those including the foliose plants. The branched plants studied here are, therefore, concluded to belong in a single species, Halymenia durvillei, irrespective of their great external variations. As Halymenia microcarpa clearly fall within the range of external variations of H. durvillei, it was concluded to be synonymous with H. durvillei. The taxonomic interrelationship among the four varieties (var. formosa, var. ceylanica, var. denudata and var. edentata) remained unresolved, although apprently encompassed within the morphological range of H. durvillei