Finite Partitioning Research Articles

Transmittance optimization of tunnel shading shed for maximum energy savings and traffic safety: When replacing tunnel lighting in threshold zone

Tunnel shading shed instead of tunnel lighting is one of the ideal ways to reduce the tremendous energy consumption at the entrance (section 2.1), but at present the length of tunnel shading shed and illuminance inside tunnel shading shed rarely meet the relevant technical requirements (section 2.2). Although some literature estimated the energy saving benefits of tunnel shading shed when replacing tunnel lighting in the threshold zone (section 2.2.1), there is no study on the conditions for maximum energy saving, the impact of energy saving on safety and the energy-saving efficiency in all time and all weather. To solve the above problems, suggest a multi-objective optimization condition of transmittance for maximizing energy savings improving traffic safety (section 3.3.2). In addition, propose an efficient sunlight simulation method based on finite element partitioning (section 3.3.1), derive a formula for precise energy-saving efficiency of tunnel shading shed (section 4.2.1), and analyze factors affecting energy-saving efficiency. The results show that: Suitable transmittance can simultaneously maximize the energy savings of tunnel shading shed (section 4.2.2) and improve traffic safety in the tunnel portal area (section 4.3). And the energy-saving efficiency on sunny summer days is not the greatest. It provides the theoretical and methodological support for making full use of sunlight and saving tunnel lighting electric energy.

Note on the finite vertex-based partitioning of supramolecular chain in Dialkyltin

ABSTRACT Complex networks are difficult to understand and deal with, yet building a graph of any complex and huge structure, whether chemical or computer-related, is quite straightforward. In the form of a graph theory view, it becomes simple to design networks. Each component's recognition is aided by the ease of its production in the form of graph theory. Finding a vertex (node or atom) in a structure is similarly difficult; in this instance, resolvability parameters come into play. This technique plays a significant role in managing or allowing access to each vertex in relation to some chosen vertices called a resolving set that shapes an entire cluster of vertices into a unique form and every single vertex is easy to recognise or locate, whether the small or large the structure. This article contributes the bounds on the parameter of partition dimension of chemical complexes in dialkyltin of supramolecular chain from N-Salicylidene-L-Valine. We supposed the complexes of chains from 2,3,4 and another chemical network, and we demonstrated that the number of vertices has a significant impact on the composition of resolving partition sets.

A scaled boundary finite element partitioning based reduced order algorithm for the elastic analysis of cyclically symmetric structures

AbstractAn efficient reduced order algorithm is proposed for the elastic SBFE analysis for 2‐D cyclic symmetric structures with or without a common node. The general stiffness matrices of scaled boundary finite element (SBFE) is proved to be block‐circulant, and can be constructed via the basic region, instead of the whole computing domain. Thus, the expense on eigenvalue analysis required in generating stiffness matrix can be significantly reduced, and the solution scale can be reduced by partitioning the system equation into a series of small independent subproblems. Furthermore, the presented algorithm is combined with the Woodbury formula to reduce the computational cost on the analysis of incomplete cyclically symmetric structures, the original system equation is transformed into the equations with block‐circulant coefficient matrices, which is efficiently solved by partitioning algorithm. Four numerical examples are provided to demonstrate the effectiveness and advantages of the proposed approach.

МЕТОДИЧЕСКИЕ АСПЕКТЫ ПРИМЕНЕНИЯ ЧИСЛЕННОГО ПРОЧНОСТНОГО АНАЛИЗА СИЛОВОГО КАРКАСА КВАДРОЦИКЛА

The design of an ATV structure is a complex engineering task, where the development of a load-bearing frame is one of the priorities, which requires a systematic methodology. Purely analytical approaches to calculations, the results of which can be used in the development of a threedimensional tubular frame structure, are now becoming a thing of the past, since the assumptions used in analytical methods give a significant calculation error, which makes it possible to obtain only a very approximate picture of the distribution of stresses and resulting deformations of the structure. It is also necessary to take into account that modern design technologies provide for the simultaneous use of various profiles of not only round, but also more complex sections, which should provide the necessary functionality of different sections of the frame (while providing a sufficiently large number of structural requirements for it), but significantly complicates the calculation procedures. With such input data, preliminary virtual electronic simulation of real products in combination with subsequent numerical engineering analysis is optimal and allows taking into account various design and technological nuances. Such software systems as CATIA related to PLM-systems (PLM – English product lifecycle management system) make it possible to perform both product modeling and, in fact, a series of numerical experiments within a single interactive environment. In the conditions of real design at the production facilities, such works are methodologically undeveloped and innovative. The purpose of the article is to consider approaches to optimizing the design of the power frame of an ATV using software computer engineering analysis tools and a previously created electronic geometric model of an ATV. In particular, the issues of preparing a model for subsequent finite element partitioning, evaluating the results of a numerical study in relation to evaluating the performance of the designed power frame of an ATV under the conditions of using the component base of previously developed power frames of motorcycles and buggies are touched upon.

A partitioned iterative method based on externally embedded cooling water pipe elements for mass concrete temperature field

A partitioned iterative method based on externally embedded cooling water pipe elements for mass concrete temperature field

Вирішення сучасних проблем динаміки технічних систем

This paper overviews the main results obtained over the past few years at the Department of Hydromechanical Systems Dynamics and Vibration Protection Systems, Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, in the solution of current problems in the dynamics of liquid-propellant rocket engines (LPREs), liquid-propellant launch vehicle pogo stability, vibration protection system dynamics, the gas dynamics of aircraft gas turbine engine components, and the dynamics of hydraulic systems with cavitating elements. These results are as follows. A mathematical model of LPRE pump dynamics was developed. The model complements a hydrodynamic model of LPRE cavitating pumps by allowing a mathematical simulation of choking regimes. An approach was developed to the construction of a nonlinear mathematical model of LPRE hydraulic line filling. The approach allows one to automatically change, if necessary, the finite element partitioning scheme of a hydraulic line in the process of its filling during LPRE startup calculations. An investigation was conducted into the startup dynamics of a multiengine liquid-propellant propulsion system that consists of four staged-combustion oxidizer-rich LPRDs with account for the possibility of their nonsimultaneous startup. The maximum values of oxidizer and fuel pressure surges and undershoots at the liquid-propellant jet system (LPJS) inlet at an engine spartup and shutdown were determined and used in determining the LPJS operability at the startup and shutdown of the RD861K sustainer engine. The pogo stability of the Cyclone-4M launch vehicle was analyzed analytically using Nyquist’s criterion. A numerical approach was developed to characterizing acoustic oscillations of the combustion products in annular rocket combustion chambers with account for the configuration features of the fire space and the variation of the physical properties of the gaseous medium with the axial length of the chamber. A prototype vibration protection system was developed and made, and its dynamic tests confirmed its high efficiency in damping impact and harmonic disturbances. Approaches were developed to the aerodynamic improvement of aircraft gas turbine engine components. Topical problems in solids grinding in a liquid medium with the use a cavitation pulse technology were solved.

Generalized desirability functions: a structural and topological analysis of desirability functions

ABSTRACTWe have Derringer and Suich's desirability functions in mind, especially, the two-sided ones in our analysis throughout this study. We propose and develop a finite partitioning procedure of the individual desirability functions over their compact and connected interval which leads to the definition of generalized desirability functions. We call the negative logarithm of an individual desirability function having a max-type structure and including a finite number of nondifferentiable points as a generalized individual desirability function. By introducing continuous selection functions into desirability functions and, especially, employing piecewise max-type functions, it is possible to describe some structural and topological properties of these generalized functions. Our aim with this generalization is to show the mechanism that gives rise to a variation and extension in the structure of functions used in classical desirability approaches.

ILT15 - A Computer Program for Evaluation of Accelerated Leach Test Data of LLW in the Hungarian NPP Paks

Computer Program ILT15 developed to accompany a new leach test for solidified radioactive waste forms in the Hungarian NPP Paks. The program is designed to be used as a tool for performing the calculations necessary to analyse leach test data, a modelling program to determine if diffusion is the operating leaching mechanism (and, if not, to indicate other possible mechanisms), and a means to make extrapolations using the diffusion models. The ILT15 program contains four mathematical models that can be used to represent the data, diffusion through a semi-infinite medium, diffusion through a finite cylinder, diffusion plus partitioning of the source term and solubility limited leaching. The program is written in C++ in the Borland C++ Builder programming environment. A detailed description of application of this modelling computer program is given.

Reduction of surface waves in finite element analysis of oscillations of elastic liquid-containing bodies

An efficient method of exclusion of the degrees of freedom connected with high-frequency oscillations of the free liquid surface from the equations of the finite element model of a deformed liquid-containing structure is presented. The number of natural frequencies specified by the shortwave oscillations of the free surface which do not significantly affect the dynamics of loading of the bearing structure grows sharply, with a refinement of the finite element partitioning of the hydroelastic system. The higher frequencies of this subspectrum alternating with natural frequencies specified by elasticity of the structure during interaction with its liquid complicate the analysis of its dynamic characteristics and the construction of mathematical models of behavior under the action of external dynamic factors.

Comparison Between Roe's Scheme and Cell-centered scheme For Transonic Flow Pass Through a Turbine Blades Section

The finite volume method (FVM) is a discretization technique for partial differential equations, especially those that arise from physical conservation laws. FVM uses a volume integral formulation of the problem with a finite partitioning set of volumes to discretize the equations [1]. The present work employs the Cell- centred and Roe's scheme to investigate the inviscid compressible flow pass through a two dimensional blade on two types of blade shapes: Blazek and SE1050 blade models. The governing equation of fluid motion of the flow problem in hand is the Euler Equation. The behavior of this equation will depend on the local Mach number if the governing equation stated in the form as the governing equation of steady flow problem. If the local Mach number is less than one, the governing equation will behave as elliptic type of differential equation while if the Mach number is greater than one it will behave as hyperbolic type of differential equation. Elimination of the presence of those two types governing equation for the case of transonic flow problem can be achieved by representing the Euler equation in unsteady form. So the equation becomes hyperbolic with respect to time. There are various Finite Volume Methods that can used for solving hyperbolic type of equation, such as Cell-centered scheme [2], Roe Upwind Scheme [3] and TVD Scheme [1]. Those computer codes apply in the case of inviscid two dimensional compressible flow pass through blades of turbine. The present work focuses on two computer codes, first based on Cell Centre scheme and the second one based on Roe's scheme.

Comparison between Cell-Centered Schemes Computer Code and Fluent Software for a Transonic Flow Pass through an Array of Turbine Stator Blades

The Finite Volume Method (FVM) is a discretization method which is well suited for the numerical simulation of various types (elliptic, parabolic or hyperbolic, for instance) of conservation laws; it has been extensively used in several engineering fields. The Finite volume method uses a volume integral formulation of the problem with a finite partitioning set of volumes to discretize the equations [. the developed computer code based Cell-centered scheme and Fluent software had been used to investigate the inviscid Transonic Flow Pass Through an array of Turbine Stator Blades. The governing equation of fluid motion of the flow problem in hand is assumed governed by the compressible Euler Equation. Basically this equation behave as a mixed type of partial differential equation elliptic and hyperbolic type of partial differential equation. If the local Mach number is less than one, the governing equation will behave as elliptic type of differential equation while if the Mach number is greater than one it will behave as hyperbolic type of differential equation. To eliminate the presence a mixed type behavior, the governing equation of fluid motion are treated as the governing equation of unsteady flow although the problem in hand is steady flow problems. Presenting the Euler equation in their unsteady form makes the equation becomes hyperbolic with respect to time. There are various Finite Volume Methods can used for solving hyperbolic type of equation, such as Cell-centered scheme [, Roe Upwind Scheme [ and TVD Scheme [. The present work use a cell centered scheme applied to the case of flow pass through an array of turbine stator blades. The comparison carried out with the result provided by Fluent Software for three different value of back pressure. The developed computer code shows the result close to the Fluent software although the Fluent software use a Time Averaged Navier stokes equation as its governing equation of fluid motion.

A new numerical method to calculate inhomogeneous and time-dependent large deformation of two-dimensional geodynamic flows with application to diapirism

SUMMARY A key to understand many geodynamic processes is studying the associated large deformation fields. Finite deformation can be measured in the field by using geological strain markers giving the logarithmic strain f = log 10 (R), where R is the ellipticity of the strain ellipse. It has been challenging to accurately quantify finite deformation of geodynamic models for inhomogeneous and time-dependent large deformation cases. We present a new formulation invoking a 2-D marker-in-cell approach. Mathematically, one can describe finite deformation by a coordinate transformation to a Lagrangian reference frame. For a known velocity field the deformation gradient tensor, F, can be calculated by integrating the differential equation DtFij = LikFkj, where L is the velocity gradient tensor and Dt the Lagrangian derivative. The tensor F contains all information about the minor and major semi-half axes and orientation of the strain ellipse and the rotation. To integrate the equation centrally in time and space along a particle’s path, we use the numerical 2-D finite difference code FDCON in combination with a marker-in-cell approach. For a sufficiently high marker density we can accurately calculate F for any 2-D inhomogeneous and time-dependent creeping flow at any pointforadeformationfupto4.Comparisonbetweentheanalyticalandnumericalsolutionfor the finite deformation within a Poiseuille‐Couette flow shows an error of less than 2percent for a deformation up to f = 1.7. Moreover, we determine the finite deformation and strain partitioning within Rayleigh‐Taylor instabilities (RTIs) of different viscosity and layer thickness ratios. These models provide a finite strain complement to the RTI benchmark of van Keken et al. Large finite deformation of up to f = 4 accumulates in RTIs within the stem and near the compositional boundaries. Distinction between different stages of diapirism shows a strong correlation between a maximum occurring deformation of f = 1, 3 and 4, and the early, intermediate and late stages of diapirism, respectively. Furthermore, we find that the overall strain of a RTI is concentrated in the less viscous regions. Thus, spatial distributions and magnitudes of finite deformation may be used to identify stages and viscosity ratios of natural cases.

A bubble-inspired algorithm for finite element mesh partitioning

SUMMARY This paper presents a bubble-inspired algorithm for partitioning finite element mesh into subdomains. Differing from previous diffusion BUBBLE and Center-oriented Bubble methods, the newly proposed algorithm employs the physics of real bubbles, including nucleation, spherical growth, bubble–bubble collision, reaching critical state, and the final competing growth. The realization of foaming process of real bubbles in the algorithm enables us to create partitions with good shape without having to specify large number of artificial controls. The minimum edge cut is simply achieved by increasing the volume of each bubble in the most energy efficient way. Moreover, the order, in which an element is gathered into a bubble, delivers the minimum number of surface cells at every gathering step; thus, the optimal numbering of elements in each subdomain has naturally achieved. Because finite element solvers, such as multifrontal method, must loop over all elements in the local subdomain condensation phase and the global interface solution phase, these two features have a huge payback in terms of solver efficiency. Experiments have been conducted on various structured and unstructured meshes. The obtained results are consistently better than the classical kMetis library in terms of the edge cut, partition shape, and partition connectivity. Copyright © 2012 John Wiley & Sons, Ltd.

An Alternative View of Continuous Forest Inventories

Abstract A generalized three-dimensional concept of continuous forest inventories applicable to all common forest sample designs is presented and discussed. The concept recognizes the forest through time as a three-dimensional population, two dimensions in land area and the third in time. The sample is selected from a finite three-dimensional partitioning of the population. The partitioning is analogous to carving the volume into pieces like a three-dimensional jigsaw puzzle. Each puzzle piece is defined by the selection volumes of observation sets on the individual trees existing in the forest during the period of interest. The concept is a temporal extension of an alternative view of forest sampling offered in Roesch et al. (1993, Sur. Methods 19(2):199–204) and results in a finite number of independently selected three-dimensional sample units.

The node capacitated graph partitioning problem: A computational study

In this paper we consider the problem ofk-partitioning the nodes of a graph with capacity restrictions on the sum of the node weights in each subset of the partition, and the objective of minimizing the sum of the costs of the edges between the subsets of the partition. Based on a study of valid inequalities, we present a variety of separation heuristics for cycle, cycle with ears, knapsack tree and path-block cycle inequalities among others. The separation heuristics, plus primal heuristics, have been implemented in a branch-and-cut routine using a formulation including variables for the edges with nonzero costs and node partition variables. Results are presented for three classes of problems: equipartitioning problems arising in finite element methods and partitioning problems associated with electronic circuit layout and compiler design. © 1998 The Mathematical Programming Society, Inc. Published by Elsevier Science B.V.

Stretching lineations in transpressional shear zones: an example from the Sierra Nevada Batholith, California

Ductile shear zones and associated stretching lineations are generally considered to be the result of two-dimensional, simple shear deformations, with stretching lineations interpreted to rotate into parallelism with the direction of tectonic transport with increasing deformation. However, stretching lineations perpendicular to the inferred tectonic transport direction are displayed by some shear zones. Field studies in the Sierra Nevada batholith have revealed a single shear zone (the Rosy Finch-Gem Lake shear zone) that contains both steeply-plunging stretching lineations in older metamorphosed sedimentary and granitic rocks, and shallowly-plunging stretching lineations in syntectonic granitoids. Dextral sense-of-shear indicators are found in all these units and deformation occurred simultaneously along the length of the shear zone.Theoretical strain modeling indicates that stretching lineations can be either horizontal or vertical within transpressional shear zones. To investigate the kinematics of three-dimensional deformation, we examine the role of stretching lineations which form as a result of finite strain, including the possibility of partitioning a component of the strike-slip movement onto shear bands. Comparing the field data with the strain modeling, we interpret the along-strike variation in lineation behavior within the Rosy Finch-Gem Lake shear zone to be a result of the differences in finite strain recorded by different units. The older units, showing steeply-plunging lineation, have recorded more finite strain across a narrower shear zone than the syntectonic granites which record shallowly-plunging lineations. We conclude that the orientation of the lineation within transpressional shear zones does not necessarily correlate with the transport direction, but may reflect along-strike variations in finite strain and/or strain partitioning.

A partitioning technique for the finite element solution of electromagnetic scattering from electrically large dielectric cylinders

A finite element partitioning scheme has been developed to reduce the computational costs of modeling electrically large geometries. In the partitioning scheme, the cylinder is divided into many sections. The finite element method is applied to each section independent of the other sections, and then the solutions in each section are coupled through the use of the tangential field continuity conditions between adjacent sections. Since the coupling matrix is significantly smaller than the original finite element matrix, it is expected that both the CPU time and memory costs can be significantly reduced. The partitioning scheme is coupled to the bymoment method to account for the boundary truncation. Numerical results are presented to demonstrate the efficiency and accuracy of the method.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A learning criterion for stochastic rules

This paper proposes a learning criterion for stochastic rules. This criterion is developed by extending Valiant's PAC (Probably Approximately Correct) learning model, which is a learning criterion for deterministic rules. Stochastic rules here refer to those which probabilistically asign a number of classes, {Y}, to each attribute vector X. The proposed criterion is based on the idea that learning stochastic rules may be regarded as probably approximately correct identification of conditional probability distributions over classes for given input attribute vectors. An algorithm (an MDL algorithm) based on the MDL (Minimum Description Length) principle is used for learning stochastic rules. Specifically, for stochastic rules with finite partitioning (each of which is specified by a finite number of disjoint cells of the domain and a probability parameter vector associated with them), this paper derives target-dependent upper bounds and worst-case upper bounds on the sample size required by the MDL algorithm to learn stochastic rules with given accuracy and confidence. Based on these sample size bounds, this paper proves polynomial-sample-size learnability of stochastic decision lists (which are newly proposed in this paper as a stochastic analogue of Rivest's decision lists) with at mostk literals (k is fixed) in each decision, and polynomial-sample-size learnability of stochastic decision trees (a stochastic analogue of decision trees) with at mostk depth. Sufficient conditions for polynomial-sample-size learnability and polynomial-time learnability of any classes of stochastic rules with finite partitioning are also derived.

射出成形における樹脂の温度変化を考慮した金型内流動解析

The paper describes flow behavior simulation of polymer melt in cavities of injection molds to clarify the relationship between flow behavior and mold shapes under several injection conditions. It uses FEM ; the governing equations are Stokes equation, equation of continuity and of heat conduction. Temperature in the flowing polymer melt in a mold varies spatially and temporally during injection molding process. The former is considered in finite partitioning of the unisothermal region by means of Tridiagonalized Partition Method (Zienkiewicz, 1967), the latter in the respective FEM analysis for flow and for heat repeated alternatively by the same time increment. In comparing the results of analysis with the experiment (Short-Shot Method), the analysis shows that the simulation is useful as a prediction of melt-front shape in the process and a generating position of weld-line, but quantitatively agrees not well with the experiment in the arrival time and temperature of melt-front, because of including no generating heat inside of flowing melt.

Strain factorization and partitioning in the North Mountain thrust sheet, central Appalachians, U.S.A.

By examining finite strain distribution and partitioning strain among deformation mechanisms, a model of thrust sheet deformation is established. The model takes into account kinematic history and environmental conditions. In the North Mountain thrust sheet of northern Virginia, factorizing finite strain into pure and simple shear components shows that the thrust sheet experienced 6–13% pure shear shortening parallel to the transport direction. Thrust-parallel simple shear strains increase slightly from the top of the thrust sheet toward the base. Within 500 m of the floor thrust, however, simple shear values increase markedly toward the basal thrust. This strain pattern occurs throughout the thrust sheet, overprinting earlier imbricate structures. Therefore, the finite strain in the thrust sheet may be modelled as a transport-parallel pure and simple shear applied during the major transport episode, and after thrust sheet imbrication. This transport-related strain overprints a weak layer-parallel shortening that is probably related to earlier passage of the thrust tip. Rocks in the thrust sheet with X/ Z strain ratios greater than 1.35 have a slight crystallographic preferred orientation and are therefore tectonites in a strict sense. The distribution of tectonites within the thrust sheet defines a ‘tectonite front’ that is inclined toward the foreland. In the North Mountain thrust sheet the ‘tectonite front’ also generally coincides with the transition to high-temperature deformation mechanisms, and ultimately may parallel a paleo-isotherm within the thrust wedge. Strain partitioning indicates that approximately 70% of the finite strain results from intragranular mechanisms (i.e. dislocation glide, dislocation creep and diffusion mechanisms); 25% results from calcite twinning; and less than 5% resulted from transgranular mechanisms such as pressure solution. In non-tectonites, approximately 50% of the finite strain results from pressure solution and intragranular mechanisms, with the remaining strain due to twinning in calcite.