The author published "Casualty Distance" has two characteristics, the exponential distribution and Poisson's one in the previous paper. The average of casualty distances is one of the most important elements that determine these distribution functions. The present report deals with the calculating method for estimating the mean casualty distance that have remained unsolved sufficiently when each casualty distance is unknown to be classified in the previous paper. This method is confirmed by comparing the calculated distances with the actual measured ones and distribution curve in the Uraga Channel, Shikoku-Shionomisaki coastal regions and the marine accidents requiring rescue in Japan for twety-one years.

抄録全体を表示

This report deals with the definition and consideration of "casualty distance" and its applications to marine disasters. Casualty distance is the interval from the base line drawn by a coast or center buoys to a casualty point obstructing marine traffic. The distance is the similar to the time headway of cars or ships in traffic engineering, which has two characteristics : the exponential distribution and Poisson's one. They were confirmed by comparing the calculated results with the actual conditions in the Uraga Channel and Shikoku-Shionomisaki coastal regions. These characteristics can be also applied to the survey and analysis on marine casualty by showing some numerical illustrations of the marine accidents requiring rescue in Japan and the passage widths at Urage Channel.

抄録全体を表示

As a step to establish the marine geodetic control network around Japan, we performed a simultaneous observation program of Ajisai at Titi-sima and Simosato Hy drographic Observatory (SHO) for January through March, 1988, another at Isigaki-sima and HO for July through September, 1988, and another at Minami-Tori-sima (Marcus Island) and SHO for January through March, 1989. The observation program consists of the satellite laser ranging (SLR) and taking photographic plates of Ajisai at each station. Mainly based on the obtained SLR data, the position of these first order control points, Titi-sima, Isigaki-sima and Minami-Tori-sima, were determined very precisely. For example, the baseline length between Titi-sima and SHO was measured as 937665.041 +/- 0.004m while that between Minami-Tori-sima and SNO was obtained as 2024874.042 +/- 0.007m.

抄録全体を表示

Campaigns for preventing marine casualty in restricted visibility are carried out every year, but these type of accidents to continue occur. Awareness campaigns suggest using radar suitably, observing the conduct of vessels in restricted visibility, among other precautions. However, other studies have pointed out that some navigators improperly understood how to apply rule in restricted visibility and how to use vector modes on the radar screen. When taking these situations into account, this study investigates how navigators are applying rule in restricted visibility and their understanding of vector mode. The study was conducted by questionnaires, and the results suggest the following: (1) Many navigators confuse conduct of vessels in sight of one another and conduct of vessels in restricted visibility.(2) Some navigators understanding of vector mode is dubious. In the final part of paper, measures for preventing marine casualties are discussed.

抄録全体を表示

The Tonankai and Nankai earthquake is said to occur 80-90% of the probability in 50 years. Height of tsunami by the earthquake is predicted more than 1.5m in the Port of Osaka. If many ships evacuate at once, they will be in panic in Osaka Bay. Here the Hazard Chart of Tsunami in Osaka bay is proposed for vessel evacuation in safety. Mutual vessels' distances and distance to shore line are estimated around 2,000m. According to statistical data about 110 vessels exist in Osaka Bay a day, the surface area of Osaka Bay has enough to evacuate all of those vessels. Some ban areas and the emergency tracks are designed in the Hazard Evacuation Chart for the dangerous cargo and the large commercial ships, and the Chart is designed for the general cargo ships and the small boats, respectively.

抄録全体を表示

Measurement technique of CO₂ for coastal seas is developed and applied to elucidate CO₂ dynamics in the coastal regions, where the photosynthetic rate is far larger than that in the open sea and the short-term change is significant. Continuous measurements of salinity, pH and DO were conducted at three stations in Osaka Bay. The values of CO₂ related terms were calculated using a classical method that uses pH and total alkalinity. Dissolved inorganic carbon (DIC) and DO fluctuated with high correlation (R² = 0.97). This suggests that CO₂ system can be measured by this method in coastal regions. DO and pCO₂ (CO₂ partial pressure) records in the eastern Osaka Bay, where primary production is significant, indicated prominent diurnal variations which correspond to diurnal irradiation variations. In contrast, magnitudes of DO and pCO₂ variations were smaller in a well mixed reason in the western Osaka Bay.

抄録全体を表示

On the previous report, the authors gave an outline of the wooden harbour launches which also served as tug. With regard to those small boats, few papers and reference data are available at present. Moreover, since the publication of the first report various kinds of light scantling boats and small harbour launches have been launched at Kobe Port. The authors present in this report the design and some particulars concerning the high speed boats out of those. To the technical progress on wooden ship building this record will make some contributions.

抄録全体を表示

　近年の世界経済の急速な発展に伴い，グローバルな物資の輸送が頻繁に行われている．特に，海上輸送を担う船舶の大型化・増加により，海上輸送は今後もより一層重要となる．一方で，海上輸送が連続的になれば，航行海域内の船舶輻輳度が増し，海難事故多発の要因となる．また，船舶量の増加に伴い，入港時に，港外で待機する沖待ちにより，燃料費消費および船員運賃等の経済的損出だけでなく，船舶からの排ガスによる大気環境汚染等の問題が発生する．これらの問題を解決するには，まずはじめに現状での船舶の航行実態を詳細に把握する必要がある．そのため，本稿では，船舶に搭載が義務付けられているAISデータの解析により，大阪湾における船舶の航行実態の把握を行った結果を報告する．

抄録全体を表示