Ito's Method Research Articles

Simplified buckling-and-contact-based expansion method for assessment of crashworthiness of double-hulled ship structure

Ship-to-ship collision events can have severe consequences such as loss of life and environmental degradation. For this reason, modern ship designs are required to incorporate a double-hulled structure to prevent inner-hull damage from such events. Using the experimental or numerical method to analyze the crashworthiness of double-hulled ship structures entails much effort, for which reason neither method is easy to adopt at the early design stage. In this paper, an existing simplified method called Ito's method is improved by a new buckling-and-contact-based expansion method. This method can be applied to double-hulled-structure or outer-hull-local-rupture failure mode. The perpendicular bow-to-side collision scenario is assumed for a conservative estimation of damage to a double-hulled structure. The method was verified in the present study by numerical ship collision simulations of several cases. The results for the buckling-and-contact-based expansion method and numerical simulation were similar for a blunt shape of striking body but different for a sharp shape.

A Study on Uncertainty of Discharge in River Channel Using Stochastic Partial Differential Equation

The physical systems are modeled by differential equations in engineering problems. If all the parameters involved in a physical system can be known, with the initial and boundary conditions, one can predict the time evolution of the physical system by solving the govern differential equations.But the more general case is that we do not know the parameters and conditions precisely because the real problems in engineering are all governed by some very complex nonlinear systems. So that the parameters and initial, boundary conditions may fluctuate randomly or at least it appears to us in that way.One way to deal with that situation is to use stochastic differential equations. The theory of stochastic ordinary differential equations has been well developed since K. Ito [2] introduced the stochastic integral and the stochastic integral equation in the mid-1940s. Recently, K. Yoshimi and T. Yamada [5] have used this method to study the uncertainty of discharge due to the random fluctuation in precipitation.The present study tried to general Ito's method to the shallow water equation which is a partial differential equation, to study the uncertainty of discharge due to the randomness effects in space by changing the partial differential equation to an ordinary differential equations using the Lagrange point of view. As a result, we proposed a Boltzmann-type equation to govern the time evolution of the probability density function of discharge and water level in river channel and show the result of simulation.

伊東忠太の「建築進化論」について(下)その意義と作用

The aim of the enunciation of "The theory of architectural evolution" by Chuta Ito in 1907 was to propose the "Evolutionalism" in architecture. It is a design method for the creation of architectural style of Japan on the basis of Japanese architecture in the past. It was criticized by architects who stood for rationalism or modernism. But, they also had high regards for the traditional architecture of Japan, and made efforts toward expression of Japanese characteristic in the modern building. Japanese pavilion at the Paris Expo of 1937 designed by Junzo Sakakura and a series of works by Kenzo Tange in the 1950's were highly evaluated on the international stage. Their design method was also similar to Ito's method of "Evolutionalism", even though there were some differences between their manners of application of the traditional ones.

X‐Ray Diffraction Studies on Molecular Semiconductors Based on Charge‐Transfer Complexes of Substituted Phenothiazines with 2,3‐Dichloro‐5,6‐dicyano‐p‐benzoquinone

AbstractX‐ray powder diffraction data on the molecular semiconductors based on the 1:1 charge‐transfer complexes of the electron donors, viz. phenothiazine (PTZ), 2‐chlorophenothiazine (CPZ), 2‐acetyl phenothiazine (APZ) and 2‐(trifluoromethyl)‐phenothiazine (TPZ) with 2,3‐dichloro‐5,6‐dicyano‐p‐benzoquinone (DDQ) have been reported in this paper. The indexing has been done by Ito's method. All the complexes have been found to have orthorhombic crystal structures. The lattice parameters for the individual complexes are as follows: (i) PTZ‐DDQ: a = 6.020 Å, b = 9.775 Å, c = 24.280 Å; (ii) CPZ‐DDQ: a = 5.830 Å, b = 8.070 Å, c = 20.280 Å; (iii) APZ‐DDQ: a = 5.055 Å, b = 7.955 Å, c = 19.520 Å; (iv) TPZ‐DDQ: a = 5.130 Å, b = 8.195 Å, c = 19.850 Å.

X‐ray Diffraction Studies on the Molecular Semiconductors Based on the Charge‐Transfer Complexes of Some Substituted Phenothiazines with Iodine

AbstractThe powder X‐ray diffraction data on some molecular semiconductors based on the charge transfer complexes of three substituted phenothiazines viz., phenothiazine (PTZ), 2‐chlorophenothiazine (CPZ), and 2‐(trifluoromethyl)phenothiazine (TPZ) with molecular iodine have been reported in this paper. The indexing of the data has been done by Ito's method. All the complexes have been found to have orthorhombic crystal structures. The lattice parameters for the individual complexes are as follows: equation image .These results indicate that the segregated stacking of mixed valence with neutral and cationic donor moieties and polymeric iodide species, two pentaiodides linked with one trüodide forming a staircase delocalized structure, are present in these complexes. This may be possibly the reason for high electrical conductivity of these complexes. However, the charge transfer complexes of iodine with 2‐acetylphenothiazine (APZ), N‐acetylphenothiazine (NAPZ) and N‐benzoylphenothiazine (NBPZ) give no diffraction patterns indicating that the molecular semiconductors based on these complexes exist in amorphous form. This is further supported by very low electrical conductivities of these complexes. This structural information is quite useful in discussing the electronic properties of this class of molecular semiconductors.

Stochastic analysis of linear structures subjected to multicorrelated filtered noises

A procedure is proposed to evaluate the mean square response of a linear system subjected to a multicorrelated, stationary or non-stationary, filtered vector process. By applying Ito's method, the multicorrelated stochastic process is considered as a white noise filtered by a set of first order linear differential equations. A closed form solution is given for the estimation of the cross-covariance matrix in the time domain, for the stationary case. Also presented is a step-by-step solution procedure to evaluate the evolutive cross-covariance matrix, for the non-stationary case. Numerical results are given for the seismic analysis of structures placed on layered soil, and idealized as a lumped mass system subjected to a white noise process at the bedrock.

Subsolidus Equilibria in the System MgO–GeO2–MgF2

Four MgO‐GeO2‐MgF2 compounds, analogous to the humite minerals, were synthesized by solid state reaction by substituting germanium for silicon. The 43 selected compositions were sintered at 800° to 1200°C. Solid state compatibility relations were established from petrographic and X‐ray diffraction analyses. The optical properties and characteristic X‐ray diffraction data for the four MgO‐GeO2‐MgF2 compounds were determined, and 2MgO.GeO2 MgF2, 4MgO.2GeO2 MgF2, and 6MgO.3GeO2 MgF2 were indexed by Ito's method.

Barringtonite—A new hydrous magnesium carbonate from Barrington Tops, New South Wales, Australia

SummaryBarringtonite, a new hydrous magnesium carbonate of composition MgCO3,2H2O, is recorded from Sempill Creek, Barrington Tops, New South Wales, where it occurs as nodular encrustations on the surface of olivine basalt. The mineral is triclinic, biaxial positive, has refractive indices α = 1·458, β = 1·473, γ = 1·501, 2Vγ = 73° 44′, and using Ito's method (1949) cell dimensions α = 9·155 Å, b = 6·202 Å, c = 6·092Å, α = 94· 00′, β = 95· 32′, and γ = 108° 72′. The three strongest lines on an X-ray powder photograph give d values of 8·682, 3·093, and 2·936 Å.

X-ray and differential thermal analysis studies on the 8-quinolinol and substituted 8-quinolinol metal chelates of thorium (IV), uranium (VI) and scandium (III)

The solvated and normal 8-quinolinol and substituted 8-quinolinols chelates of scandium (III), thorium (IV), and uranium (VI) were studied by X-ray diffraction and differential thermal analysis (DTA). The unit cell dimensions for the chelates were calculated from the X-ray data using Ito's method. DTA studies showed that the solvate molecule was evolved, giving rise to endothermic peaks in the 100–300° temperature range. This peak was followed by endothermic peaks caused by the general decomposition reaction. The E a for the desolvation of UO 2(Ox) 2·HOx was 28 kcal mole −1 while the ΔH was 20 ± 2 kcal mole −1.