Fisheries Engineering
Online ISSN : 2189-7131
Print ISSN : 0916-7617
ISSN-L : 0916-7617
Volume 38, Issue 1
Displaying 1-11 of 11 articles from this issue
  • Osamu SHOTAKE, Takayoshi MIKAMI, Nariharu YAMASHITA, Katsuaki NASHIMOT ...
    2001Volume 38Issue 1 Pages 1-8
    Published: 2001
    Released on J-STAGE: June 01, 2018
    JOURNAL OPEN ACCESS
    Emotional information included in the voice is strongly influenced by its acoustic parameters. On the assumption that the emotion of sudden emergency is a mix of 'surprise' and 'fright', we have started a study to distinguish sudden emergency voices of the Japanese vowel [a] from ordinary voices using [a] by analysis and comparisons of acoustic parameters included in these voices. And our final purpose is to establish a method of an urgent stopping of the winch by the distinction of a sudden emergency voice, [a]. In this paper, we investigated the change of pitch frequency (F0) and the duration of the vowel [a] voiced imitating emotions by vocalists, and we explored the parameters which enables one to distinguish [a] voiced in a sudden emergency. As a result of this investigation, we see that the parameter of distinction is the START value on the F0 curve. If this value reaches l.71 times higher than the F0 of a neutral emotion, we can see that the voice has been uttered in a sudden emergency.
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  • Kuniharu OKUDA, Mayumi MISE, Kojiro MOTOMURA, Shigeo TATSUMI
    2001Volume 38Issue 1 Pages 9-18
    Published: 2001
    Released on J-STAGE: June 01, 2018
    JOURNAL OPEN ACCESS
    In Russia, GLONASS is being developed as a positioning system which is the same as GPS. Recently, a receiver with combined GPS and GLONASS appeared, and good positioning is expected. GPS and GLONASS were used at the same time, and the positioning accuracy was analyzed by the kinematic method. The positioning by this method can be handled easily in the same way as other methods, and fix high position accuracy. Therefore, it is suitable for fish bank research which needs high position accuracy beyond the present differential method. However, it is necessary to consider the base line length the further from the reference station it is, since the position error becomes larger. As a result of the analysis, it was grasped quantitatively how much the positioning accuracy to the base line length deteriorates by the kinematic method when GLONASS was used in common. That is, the positioning accuracy of using GLONASS in common became about 3/4 that of only GPS. Besides, even though the positioning.accuracy deteriorated as the user station moves away from the reference station, it was found that it was possible to get higher accurate position by the time zone when GLONASS was used in common.
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  • Case study at East China Sea
    Keiichi UCHIDA, Yoshinori MIYAMOTO, Toshiharu KAKIHARA
    2001Volume 38Issue 1 Pages 19-24
    Published: 2001
    Released on J-STAGE: June 01, 2018
    JOURNAL OPEN ACCESS
    In this paper, the positioning accuracy of MF-DGPS at offshore fishing ground where is outside MF-DGPS coverage, is reported. The following results were obtained from the observation on board a vessel. (1) The guaranteed accuracy of MF-DGPS is able to be maintained at the offshore fishing ground that is apart 200 miles from DGPS reference station, though the accuracy is slightly low during the night. (2) It is suggested that the positioning accuracy changes because of the path of the medium frequency radio wave and the weather on way to the path. (3) PRF (perfomance) that means DGPS correction data receiving rate is thought to be the concrete value to estimate the positioning accuracy.
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  • Kazumasa IMAO, Teruaki SUZUKI, Hiroaki AOYAMA, Masanobu KAI, Naganori ...
    2001Volume 38Issue 1 Pages 25-34
    Published: 2001
    Released on J-STAGE: June 01, 2018
    JOURNAL OPEN ACCESS
    To create a new artificial shallow area in a hypoxic bay, we propose methods to determine the depth for the area and how to evaluate its effectiveness. The study was conducted in Mikawa Bay, Japan, which is a semienclosed sea and is regularly nutrient enriched. As a result, in summer, serious hypoxia is observed in the bottom layer, which becomes progressively lethal to the macrobenthos. Therefore the aim of developing a new shallow area should be to avoid hypoxia. To determine the depth of the shallow area to be newly created, we analysed field data such as macrobenthos, water temperature and dissolved oxygen concentration. We then used those results to estimate the survival rate of the short-necked clam (Ruditapes philippinarum), which depends on water temperature, dissolved oxygen concentration and glycogen content in the body. We proposed that the depth of the artificial area should be where the survival rate for the short-necked clam will be over 70%. The effect of constructing the shallow area was assessed on the basis of the water purification function, which is defined by the removal of particulate organic nitrogen by macrobenthos. All field data and numerical results, which predicted the effects of constructing the new shallow area, were managed in a Geographic Information System (GIS). The new methods and evaluation criteria presented in this paper have both environmental and economic merits.
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  • Used 100V Electric Line in a Ship for an Experiment of Network
    Masaru KOZUMA, Hisaaki TAKAYAMA, Shigeaki YADA
    2001Volume 38Issue 1 Pages 35-42
    Published: 2001
    Released on J-STAGE: June 01, 2018
    JOURNAL OPEN ACCESS
    We had studied the experimental survey of ship's network to use the INMARSAT-A or the satellite marinephone (N-STAR) with a ship telephone line, which have got a certain results. But it has misgivings to use the line for a long time that never be use for ship general communication or a state of emergency. In this study, we experimented the efficiency of ship's electric power supply line using its simple LAN instead of ship's data communication line. From the experiment, we understood that the access server from three places of the ship without exclusive communication line for a conventional ship. And we were able to use on.the ship's network repeatedly that is meteorological information, navigation alert, news, mail and other multimedia information from the Internet and the ship's host station.
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  • Shigeaki SHIOTANI
    2001Volume 38Issue 1 Pages 43-51
    Published: 2001
    Released on J-STAGE: June 01, 2018
    JOURNAL OPEN ACCESS
    The information of ship waves generated by a ship are very important to prevent the damage of a small boat or the cage for fishing aquaculture. In the previous paper, it was discussed about the simplified estimation methods and the characteristics of ship waves generated by three kinds of small actual boats. As more developed research of the previous paper, this paper deals with the numerical computation of ship waves generated by a small vessel of the displacement type with the constant speed for obtaining the these quantitative characteristics in detail. The computation of ship waves was carried out to a Wigley ship model. The characteristics of this computation are the finite volume method, MUSCL-type third-order upwind differencing, Reynolds-Averaged Navier-Stokes solver for the viscous flow with a free surface. The calculated results of ship waves are compared with the experimental ones. As results, it shows that this computing method is very effective for quantitatively estimating ship waves.
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  • Ken MORI, Shiomi SHIKASHO, Kazuaki HIRAMATSU
    2001Volume 38Issue 1 Pages 53-59
    Published: 2001
    Released on J-STAGE: June 01, 2018
    JOURNAL OPEN ACCESS
    In this study, We examined the properties of the responses of dissolved oxygen to physical disturbances, using the results of field observation data in a closed-water area of relatively shallow depth. We considered two disturbances : first, the thermal disturbance that consists of lighting and heating based on solar radiation in the daytime and cooling based on emission at the night ; second, the mechanical disturbances of wind-induced flow and wind-waves generated by wind action on the water surface. We found that the profiles of the water temperatures and the concentrations of dissolved oxygen were cyclic from the formation of a strong stratified layer in the daytime to, at night, the formation of a mixed layer based on thermal convective flow. Further, we found that the rate of supply of oxygen by reaeration based on wind-induced flow and wind-waves depended on the wind velocity, and that the magnitude of the rate had several times as much as the rate based on photosynthesis of phytoplankton cells.
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  • Takeshi HAMADA, Kazuhiro MATSUMURA, Yoshihiro INOUE, Yuji AKAI
    2001Volume 38Issue 1 Pages 61-68
    Published: 2001
    Released on J-STAGE: June 01, 2018
    JOURNAL OPEN ACCESS
    In Japan's sanriku coastal distinct, most Wakame (Undaria pinnatifida) farmers produce boiled and salted products after harvesting it. The authors analyzed the production system used and considered guidelines to save on labor. This paper describes the recommendations as follows: 1. Automate the process of cutting stems. Of the ll steps required to process Wakame, the cutting of stems required the largest number of workers in the production system ; 2. Move the process of cutting stems (eighth process) to the begiming of these processes, thereby improving the quality of the products since the leaves and stems can be boiled, cooled, and salted separately. Also, when placing Wakame on the cutter, it is easier to handle raw leaves than salted ones.
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  • Yoshihiro OHMURA
    2001Volume 38Issue 1 Pages 69-77
    Published: 2001
    Released on J-STAGE: June 01, 2018
    JOURNAL OPEN ACCESS
    First, I will outline the policy on the fisheries infrastructure improvement in the twenty-first century based on 'Fundamental principles of fisheries basic policy' published on December 14, 1999 by the Ministry of Agriculture, Forestry and Fisheries of Japan. Next, I review the results of research that relates the improvement works of aquatic environment. Especially, I have focused on the seawater intake works that enhances seawater exchange and have developed new multi-purpose type. The one is the seawater intake works with submerged mounds, the other is the seawater intake works with cylindrical holes. These works use wave energy and have aeration ability. As a result of hydraulic model tests, these works are proved to be for practical use. Now, the former is under construction at the Imaizumi fishing port Kagoshima Prefecture, the latter at the Hamada fishing port Shimane Prefecture. Moreover, I intend to show the effect of seawater training in the model fishing port having wide tidal range. The evaluation is done by the numerical simulation based on nonlinear long wave equation and Euler-Lagrangian method that uses neutral particles. This evaluation method is valid for grasping the seawater exchange situation quantitatively.
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  • Symposium Executive Committee
    2001Volume 38Issue 1 Pages 79-90
    Published: 2001
    Released on J-STAGE: June 01, 2018
    JOURNAL OPEN ACCESS
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  • Symposium Executive Committee
    2001Volume 38Issue 1 Pages 91-102
    Published: 2001
    Released on J-STAGE: June 01, 2018
    JOURNAL OPEN ACCESS
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