全文: "クジラ漁"
6件中 1-6の結果を表示しています
  • 宇田 道隆
    1955年 13 巻 63-72
    発行日: 1955/11/10
    公開日: 2017/09/26
    ジャーナル フリー
    In spring the water temperature innarrow straits in the Inland Sea indicates vertical homotherm distribution and relatively low value due to the turbulent mixing by strong tidal current, and is feasible to cause the dense fog, especially in the warm sector of cyclone with the consequent sea-disaster such as the case of "Shiun-Maru" (May 11, 1955). In the NE sea-district of Japan the most freguent occurrence of sea fog lies in the area of cold curent. In spite of the difficulty of searching, the whalers find the great concentration of whales at the head of the cold current where dense fog occurs most freguently. (See Fig.1 a〜f)
  • 中村 周作
    2017年 69 巻 4 号 485-499
    発行日: 2017年
    公開日: 2018/02/23
    ジャーナル フリー


  • 田中 昌一
    1956年 22 巻 6 号 330-337
    発行日: 1956/10/25
    公開日: 2008/02/29
    ジャーナル フリー
    Maximum likelihood estimates of biological populations have been obtained on the basis of se-quential tagging experiments without replacement. At the time just before the t-th sample (t=1, 2, …, T) is taken, the size of a population may be represented by Nt-1 and the number of tagged individuals by At-1. Let us assume xt tagged individuals are found in t-th sample of size nt drawn at random from this population. Then, mt individuals are taken out from the population again, tagged and released regardless whether or not they have been tagged before. If yt among me has already been tagged, an actual increase in tagged individuals during the t-th experiment is mt-yt-xt.
    Under usual circumstances it could be assumed that Nt-l_??_nt and Nt-1_??_At-1; hence xt is ex-pected to follow Poisson distribution with mean of ntAt-1/Nt-1, and yt is negligibly small. From these models the maximum likelihood estimates have been derived by using the successive approxi-mations as DELURY did (formulae 1-6). Approximate coefficient of variation of estimated 1/N0 or F=∑nt/N0 is given by the reciprocal of square root of the total number recaptured (formulae 11 and 12).
    If At-1 is not too small in contrast with Nt-1, the binomial distribution is more suitable than Poisson distribution to be used as a basic mathematical model. The estimates are obtained in the same procedure as before (formulae 7 and 8).
    When data drawn from a constructed binomial population were analysed by using At and At', for both models of binomial and Poisson populations, it has been found that the effect of the difference of population models is small enough, and that the effect of neglecting yt is not serious, though the results based on correct At are always smaller than on approximate At' (Tables 1 and 2).
    For another example, the methods are applied to the data obtained from the marking experi-ments of fin whale which were carried out in the 1954 and 1955 seasons in one of three major whaling grounds of the northern North Pacific, located north of Aleutian Islands and east of 180° meridian. On the basis of biological surveys and tagging experiments it has been believed so far that there are a few different populations, each frequenting to one of these whaling grounds where they would stay for a considerable length of the season every year. This fact makes the situation simple for the statistical estimation by marking experiments. The data and results of calculations are shown in Tables 3-6. In addition, catch-effort records (Table 7) are analysed by DELURY's method to compare them with the results of the marking experiments. Although these estimates have only a little reliability, it might be safely said that the size of the fin whale population in the region under study is 5, 000-50, 000.
  • 根本 昌彦, 秋林 幸男
    1999年 45 巻 2 号 13-18
    発行日: 1999/10/01
    公開日: 2017/08/28
    ジャーナル フリー
  • 佐々木 理, 永広 昌之, 根本 潤, 鹿納 晴尚, 望月 直
    2013年 93 巻 75-82
    発行日: 2013/03/31
    公開日: 2017/10/03
    ジャーナル フリー
    The 2011 earthquake off the Pacific coast of Tohoku and the subsequent tsunami severely damaged many cultural facilities along the eastern coast of Japan. The Committee for Salvaging Cultural Properties was established in Tokyo through an appeal to the Agency for Cultural Affairs, and the local headquarters of the Committee in Miyagi was established in the Sendai City Museum beginning April 19. The staffs of local museums and the Cultural Properties Protection Section of Miyagi Prefecture joinded operations to salvage cultural properties in Miyagi. Tohoku University Museum joined this enterprise to salvage natural-history collections from 6 facilities. Many museum collections were lost in this disaster, but most of the collections exhibited in the Utatsu Ichthyosaur Museum were successfully rescued. After emergency salvage operations decreased, the Miyagi Liason Conference for preserving damaged cultural properties was established to assume salvage operations from the local headquarters, which was closed by the end of July. In anticipation of the next disaster, manuals for salvaging cultural properties from damaged facilities should be prepared based on our direct experience; detailed information on the location of specimens will be required, and contact addresses for specimen managers and curators. As disaster-affected cultural properties are returned from restoration to the damaged museums, many curators will be needed to resume museum activities, including research, exhibition, and education. To secure the many curators needed in the damaged area, we must consider flexible solutions, including establishment of NPOs for reconstructing damaged museums with financial support from the disaster-affected museums recovery project.
  • 川内 浩司
    1979年 53 巻 11 号 R141-R150
    発行日: 1979年
    公開日: 2008/11/21
    ジャーナル フリー