On the Analysis of ships' Oscillations as a Time Series
On the Analysis of ships' Oscillations as a Time Series
复制标题
船舶振动作为时间序列的分析
DOI：
10.2534/jjasnaoe1952.1956.99_47
复制
发表时间：
1956
期刊：
影响因子：
--
通讯作者：
Y. Yamanouchi
中科院分区：
文献类型：
--
作者：
Y. Yamanouchi
船舶在航行中的振动是由海浪产生的，海浪和其他地球物理现象一样，都含有随机元素。最近，概率论和统计推断被用来作为分析这些地球物理现象的手段。也就是说，这些现象的记录被用作时间序列，其中包含遵循随机规律的变化元素。本文从这个角度研究了船舶运动，并成功地将其分析为一个平稳的时间序列。首先阐明了船舶振动时间序列的相关图可以看作是某种自回归过程的一个样本，然后介绍了理论相关图和船舶振动谱密度的分析方法。明确了以下几点：(1)利用时间序列的周期图，可以从相当不规则的记录中清楚地找到船舶振动的显著周期。(2)用调和分析的方法分析，可以得到从统计推断的角度检验有意义程度的振动要素波的周期和幅度。(3)通过计算海浪中的船舶振动记录的相关图，我们可以得到其振动要素的真实周期和衰减因子。(4)通过对相关图进行傅里叶-余弦逆变换，我们可以直接得到船舶振动的频谱，并可以阐明由海浪要素的周期和阻尼力组成的对船舶的强迫作用力的结构。(V)如果我们合成海浪的相关图和船舶自由振动的性质，我们可以得到船舶在波浪上运动的理论相关图和谱，并由此获得船舶在不规则波上的强迫运动。通过这种方法，我们可以得到船舶在不规则波上的强迫运动的理论相关图和谱。通过这种方法，我们可以得到船舶在不规则波上的强迫运动我分析了青森-函馆火车渡轮的几个摆动记录，明确了这艘船的许多特点，这些特点到目前为止我们还不知道。
The oscillations of ships under voyage are produced by the ocean waves, and the ocean waves contain randum elements like the other geophysical phenomena. Recently the theory of probability and statistical inference were used as a means of analysis of these geophysical phenomena. That is to say, the record of these phenomena were used as a Time Series that contained the elements of variance that follow the laws of randumness. If the compulsory force upon ships were regarded like this process, the oscillations of ships produced by that force may be regarded similarly.I studied the motions of ships from this standpoint, and succeeded in analizing them as a Stationary Time Series.At frst I made it clear that the Correlogram of the time series of ships oscillation can be regarded as a sample of a certain Auto-regressive Process, and then introduced the method of analysis of the theoretical Correlogram and the Spectrum Density of ships oscllations.As a result, the following things became clear : -(i) The prominent period of oscillations of ship can be found clearly from a rather irregular record by means of the Periodograms of Time Series.(ii) Analiying by the method of Harmonic Analysis, we can get the periods and amplitudes of the elemental waves of oscillations that are tested the level of significance from the standpoint of statistical inference.(iii) By calculating Correlograms from the record of oscillations of ships that are under way on ocean waves, we can get the real period and the damping factor of the elements of its oscillations, which could not be found correctly until now.(iv) By making a Fourier-Cosine Inversion from the Correlogram, we can directly obtain a Spectrum of a ships oscillation and can clarify the construction of the compulsory force upon the ship, composed of the period and the damping of elements of ocean waves.(v) If we synthesize the Correlogram of ocean waves and the nature of a ship's free oscillations, we can obtain a theoretical Correlogram and Spectrum of a ship's motion on waves, and from this the knowledge of a ship's forced motion on irregular waves.And by this method, I analized several records of oscillations of the Aomori-Hakodate Train Ferry Ship, and made clear many points of characteristics of this ship that were unknown for us untill now.