Distribution Functions of Mass Properties: A Tool for Naval Architecture

1987 ◽  
Vol 31 (04) ◽  
pp. 282-293
Author(s):  
Adrian Birbanescu-Biran
Keyword(s):  
Mass Distribution ◽  
Center Of Gravity ◽  
Distribution Functions ◽  
Mass Center ◽  
Moments Of Inertia ◽  
Mass Data ◽  
Analytic Integration ◽  
Mass Properties ◽  
Tensor Of Inertia ◽  
General Method

Dynamic sea load calculations require the lumping of the ship into a number of mass sections. For each such section, its mass, center of gravity and some components of its tensor of inertia must be calculated. Previously, this problem was solved by tedious methods. This paper presents a general method of calculating these data out of a database containing the mass data of all ship items. The method is based on the notion of distribution functions of mass properties. It is shown that two types of mass distribution functions can be used for representing all possible distributions. These functions are the step mass distribution and the second-degree mass distribution functions. Distribution functions of moments and moments of inertia can be calculated from the mass distribution functions by analytic integration and/or multiplications. The distribution functions are also an easy means of calculating the mass properties of a jumboized ship, starting from the data of the original ship.

scholarly journals Monte Carlo Calculations of the Radial Distribution Functions for a Proton?Electron Plasma

1965 ◽  
Vol 18 (2) ◽  
pp. 119 ◽  
Author(s):  
AA Barker
Keyword(s):  
Monte Carlo ◽  
Crystal Lattice ◽  
Radial Distribution ◽  
Lattice Theory ◽  
Electron Plasma ◽  
Distribution Functions ◽  
Radial Distribution Functions ◽  
Monte Carlo Calculations ◽  
Wide Range ◽  
General Method

A general method is presented for computation of radial distribution functions for plasmas over a wide range of temperatures and densities. The method uses the Monte Carlo technique applied by Wood and Parker, and extends this to long-range forces using results borrowed from crystal lattice theory. The approach is then used to calculate the radial distribution functions for a proton-electron plasma of density 1018 electrons/cm3 at a temperature of 104 OK. The results show the usefulness of the method if sufficient computing facilities are available.

Optimization and Business Analytics in Shipbuilding

2014 ◽  
Author(s):  
Dhiren Verma ◽  
Tom Goodwin
Keyword(s):  
Product Development ◽  
Mass Distribution ◽  
Business Analytics ◽  
Extended Enterprise ◽  
Product Attributes ◽  
Mass Properties ◽  
Data Consolidation ◽  
Design Requirements ◽  
Marine Engineers

This paper shall show how marine engineers can derive optimum structures that meet design requirements with the best possible mass distribution and minimum welding effort. This results in a ship that is less expensive to manufacture and maintain. This paper shall also highlight how marine engineers can rapidly highlight the effect of these designs and their changes on product attributes such as weight and balance. Providing such process and tools for data consolidation, tracking and reporting, enables constituents of the extended enterprise to contribute more to product development by focusing on identifying, managing and improving mass properties and associated opportunities, risks and uncertainties.

scholarly journals Collisionless distribution functions for force-free current sheets: using a pressure transformation to lower the plasma beta

2018 ◽  
Vol 84 (3) ◽  
Author(s):  
F. Wilson ◽  
T. Neukirch ◽  
O. Allanson
Keyword(s):  
Distribution Function ◽  
Current Sheet ◽  
Plasma Phys ◽  
Distribution Functions ◽  
Hermite Functions ◽  
Slow Convergence ◽  
Nonlinear Force ◽  
Free Current ◽  
Transformed Distribution ◽  
General Method

So far, only one distribution function giving rise to a collisionless nonlinear force-free current sheet equilibrium allowing for a plasma beta less than one is known (Allansonet al.,Phys. Plasmas, vol. 22 (10), 2015, 102116; Allansonet al.,J. Plasma Phys., vol. 82 (3), 2016a, 905820306). This distribution function can only be expressed as an infinite series of Hermite functions with very slow convergence and this makes its practical use cumbersome. It is the purpose of this paper to present a general method that allows us to find distribution functions consisting of a finite number of terms (therefore easier to use in practice), but which still allow for current sheet equilibria that can, in principle, have an arbitrarily low plasma beta. The method involves using known solutions and transforming them into new solutions using transformations based on taking integer powers ($N$) of one component of the pressure tensor. The plasma beta of the current sheet corresponding to the transformed distribution functions can then, in principle, have values as low as$1/N$. We present the general form of the distribution functions for arbitrary$N$and then, as a specific example, discuss the case for$N=2$in detail.

Physical properties of the human head: Mass, center of gravity and moment of inertia

2009 ◽  
Vol 42 (9) ◽  
pp. 1177-1192 ◽  
Author(s):  
Narayan Yoganandan ◽  
Frank A. Pintar ◽  
Jiangyue Zhang ◽  
Jamie L. Baisden
Keyword(s):  
Physical Properties ◽  
Human Head ◽  
Center Of Gravity ◽  
Moment Of Inertia ◽  
Mass Center

Non-Repair Dynamically Balanced Device of Wheel Set in Vehicles

2012 ◽  
Vol 510 ◽  
pp. 431-436
Author(s):  
Chao Liu ◽  
Chao Zou ◽  
Dong Ju Wang ◽  
Zai Lin Ge
Keyword(s):  
Mass Distribution ◽  
High Speed ◽  
Dynamic Balance ◽  
Mass Center ◽  
Physical Damage ◽  
Limited Effect ◽  
Negative Effect ◽  
Weight Method ◽  
Economy Benefit

In order to make the mass distribution of the wheel set symmetrical about the axis of the wheel axle, which is able to remove the periodical exciter source and many consequences coming from it, including having negative effect on the stationarity and stability during the running of the train, shortening the lifetime of the wheels, bearings and many other parts of the train, design a set of balanced device to regulate the mass center of the wheel set. The set of device collects data by relevant detection devices in order to find the mass distribution condition, and then regulate the circumferential positions of the objects with a certain mass in the tapered groove which can make the mass distribution of the wheel set symmetrical about the axis of the wheel axle. The device has many advantages, such as simplicity, high precision, excellent regulating effects, and, at the same time, conquers the disadvantages of many other ways. For the time being, the means to solve the problem are mainly Adding Weight Method and Removing Weight Method, which both cause physical damage to the wheel. Furthermore, these two methods have a lot of disadvantages, such as low stability, limited effect, limited repairing numbers and high labor strength. The device not only conquers these disadvantages of the two methods, but also has many advantages, and in the future, it can be automatically controlled by microcomputers. Wheel sets are very essential to the running of the train, whose quality has outstanding effect on the safety and quality of the running of the train, especially in the condition that trains run faster and faster, which requires wheel sets to meet higher standards on dynamic balance, especially for new high-speed bogie. Thus, the device has a large economy benefit and society benefit.

scholarly journals A new general method for the assessment of the molecular-weight distribution of polydisperse preparations. Its application to an intestinal epithelial glycoprotein and two dextran samples, and comparison with a monodisperse glycoprotein

1973 ◽  
Vol 135 (4) ◽  
pp. 649-653 ◽  
Author(s):  
Richard A. Gibbons ◽  
Stephen N. Dixon ◽  
David H. Pocock
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Continuous Distribution ◽  
Distribution Functions ◽  
Intestinal Epithelial ◽  
Cysticercus Tenuicollis ◽  
Molecular Weights ◽  
Two Samples ◽  
General Method

A specimen of intestinal glycoprotein isolated from the pig and two samples of dextran, all of which are polydisperse (that is, the preparations may be regarded as consisting of a continuous distribution of molecular weights), have been examined in the ultracentrifuge under meniscus-depletion conditions at equilibrium. They are compared with each other and with a glycoprotein from Cysticercus tenuicollis cyst fluid which is almost monodisperse. The quantity c−⅓(c=concentration) is plotted against ξ (the reduced radius); this plot is linear when the molecular-weight distribution approximates to the ‘most probable’, i.e. when Mn:Mw:Mz: M(z+1)....... is as 1:2:3:4: etc. The use of this plot, and related procedures, to evaluate qualitatively and semi-quantitatively molecular-weight distribution functions where they can be realistically approximated to Schulz distributions is discussed. The theoretical basis is given in an Appendix.

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