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Explicit Function (explicit + function)
Selected AbstractsInfluence of liquid bridges on the mechanical behaviour of polydisperse granular materialsINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 3 2006F. Soulié Abstract We investigate a polydisperse granular material in which the particle interactions are governed by a capillary force law. The cohesion force for a grain-pair with unequal diameters is expressed as an explicit function of the inter-particle distance and the volume of the liquid bridge. This analytical relation is validated by experiments on a reference material. Then, it is completed by a rupture criterion and cast in the form of a force law that accounts for solid contact, capillary force and rupture characteristics of a grain-pair. Finally, in order to evaluate the influence of capillary cohesion on the macroscopic behaviour, radial and axial compression tests on cylindrical assemblies of wet particles are simulated using a 3D distinct element method. Copyright © 2005 John Wiley & Sons, Ltd. [source] Hamiltonian-based error computationsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 4 2006Y. L. Kuo Abstract This paper presents two sets of the Hamiltonian for checking errors of approximated solutions. The first set can be applied to those problems having any number of independent and dependent variables. This set of the Hamiltonian can effectively indicate the errors of approximated solutions when requiring a high accuracy. The second set of the Hamiltonian has the invariant property when the Lagrangian is not an explicit function of time, even for non-conservative systems. Both sets can be formulated as error indicators to check errors of approximated solutions. Three illustrative examples demonstrate the error analyses of finite element solutions. Copyright © 2005 John Wiley & Sons, Ltd. [source] Power-delay optimization of D-latch/MUX source coupled logic gatesINTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 1 2005M. Alioto In this paper a design strategy for MUX, XOR and D-latch source coupled logic (SCL) gates is proposed. To this end, an analytical model of the delay and the noise margin as a function of the transistors' aspect ratio and bias current is first introduced. Successively, analytical equations of the transistors' aspect ratio to meet a given noise margin specification are derived as a function of the bias current, and are then used along with the delay model to express the delay as an explicit function of the bias current and noise margin. The simplified delay expression explicitly relates speed performance to power dissipation and the noise margin, thereby providing the designer with the required understanding of the trade-offs involved in the design. Therefore, the criteria proposed allow the designer to consciously manage the power-delay trade-off. The delay dependence on the logic swing is also investigated with results showing that this delay is not necessarily reduced by reducing the logic swing, in contrast with the usual assumption. Since the results obtained are valid for all SCL gates and are independent of the CMOS process used, the guidelines provided afford a deeper understanding of SCL gates from a design point of view. Copyright © 2005 John Wiley & Sons, Ltd. [source] Explicit modelling of the double-gate MOSFET with VHDL-AMSINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 3 2006Fabien Prégaldiny Abstract This paper presents a new compact model for the undoped, long-channel double-gate (DG) MOSFET under symmetrical operation. In particular, we propose a robust algorithm for computing the mobile charge density as an explicit function of the terminal voltages. It allows to greatly reduce the computation time without losing any accuracy. In order to validate the analytical model, we have also developed the 2D simulations of a DG MOSFET structure and performed both static and dynamic electrical simulations of the device. Comparisons with the 2D numerical simulations give evidence for the good behaviour and the accuracy of the model. Finally, we present the VHDL-AMS code of the DG MOSFET model and related simulation results. Copyright © 2006 John Wiley & Sons, Ltd. [source] Terminal settling velocity and drag coefficient of biofilm-coated particles at high Reynolds numbersAICHE JOURNAL, Issue 10 2010Mehran Andalib Abstract The drag force (Fd) on bio-coated particles taken from two laboratory-scale liquid,solid circulating fluidized bed bioreactors (LSCFBBR) was studied. The terminal velocities (ut) and Reynolds numbers (Ret) of particles observed were higher than reported in the literature. Literature equations for determining ut were found inadequate to predict drag coefficient (Cd) in Ret > 130. A new equation for determining Fd as an explicit function of terminal settling velocity was generated based on Archimedes numbers (Ar) of the biofilm-coated particle. The proposed equation adequately predicted the terminal settling velocity of other literature data at lower Ret of less than 130, with an accuracy >85%. © 2010 American Institute of Chemical Engineers AIChE J, 2010 [source] PID control performance assessment: The single-loop caseAICHE JOURNAL, Issue 6 2004Byung-Su Ko Abstract An iterative solution is developed for the calculation of the best achievable (minimum variance) PID control performance and the corresponding optimal PID setting in an existing control loop. An analytic expression is derived for the closed-loop output as an explicit function of PID setting. The resulting benchmark allows for realistic performance assessment of an existing PID control loop, especially when the control loop fails to meet the minimum variance performance. A PID performance index is then defined based on the PID performance bound, and its confidence interval is estimated. A series of simulated examples are used to demonstrate the utility of the proposed method. © 2004 American Institute of Chemical Engineers AIChE J, 50: 1211,1218, 2004 [source] Combination of Fragmental and Topological Descriptors for QSPR Estimations of Boiling TemperatureMOLECULAR INFORMATICS, Issue 8 2004Irina Abstract The novel QSPR equation for estimation of physicochemical properties of organic substances is proposed. This equation includes contributions depending on the counts of bonds and nonadditive contribution. The nonadditive term is represented as an explicit function of topological distances on the line graph of molecules. The original mathematical form for description of nonadditive contribution is suggested. The application of the derived equation to estimation of normal boiling temperatures for the saturated hydrocarbons (total number of compounds n=198; correlation coefficient r=0.9966; mean square deviation ,=3.4,K) has proved the effectiveness of the proposed approach. The modification of correlation equation is made for estimations of normal boiling temperatures for substances with OH and NH2 groups (n =139; r=0.9971; ,=3.9,K). [source] Output,Purchase Funding and Budgeting Systems in the Public SectorPUBLIC BUDGETING AND FINANCE, Issue 4 2002Marc Robinson Output,purchase funding systems are systems in which payments made to service delivery agencies by government are an explicit function of quantities of outputs delivered by those agencies. This article considers the feasibility of such systems for the funding of tax,financed public services. It focuses on the implications of key characteristics of public sector outputs and specifically upon the prevalence of heterogeneous outputs, the predominance of services (as opposed to physical goods), and the presence of many "contingent capacity services." [source] Equilibrium Wage-Tenure ContractsECONOMETRICA, Issue 5 2003Ken Burdett In this study we consider a labor market matching model where firms post wage-tenure contracts and workers, both employed and unemployed, search for new job opportunities. Given workers are risk averse, we establish there is a unique equilibrium in the environment considered. Although firms in the market make different offers in equilibrium, all post a wage-tenure contract that implies a worker's wage increases smoothly with tenure at the firm. As firms make different offers, there is job turnover, as employed workers move jobs as the opportunity arises. This implies the increase in a worker's wage can be due to job-to-job movements as well as wage-tenure effects. Further, there is a nondegenerate equilibrium distribution of initial wage offers that is differentiable on its support except for a mass point at the lowest initial wage. We also show that relevant characteristics of the equilibrium can be written as explicit functions of preferences and the other market parameters. [source] Generalized strain probing of constitutive modelsINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 15 2004Youssef M. A. Hashash Abstract Advanced material constitutive models are used to describe complex soil behaviour. These models are often used in the solution of boundary value problems under general loading conditions. Users and developers of constitutive models need to methodically investigate the represented soil response under a wide range of loading conditions. This paper presents a systematic procedure for probing constitutive models. A general incremental strain probe, 6D hyperspherical strain probe (HSP), is introduced to examine rate-independent model response under all possible strain loading conditions. Two special cases of HSP, the true triaxial strain probe (TTSP) and the plane-strain strain probe (PSSP), are used to generate 3-D objects that represent model stress response to probing. The TTSP, PSSP and general HSP procedures are demonstrated using elasto-plastic models. The objects resulting from the probing procedure readily highlight important model characteristics including anisotropy, yielding, hardening, softening and failure. The PSSP procedure is applied to a Neural Network (NN) based constitutive model. It shows that this probing is especially useful in understanding NN constitutive models, which do not contain explicit functions for yield surface, hardening, or anisotropy. Copyright © 2004 John Wiley & Sons, Ltd. [source] An unconditionally convergent algorithm for the evaluation of the ultimate limit state of RC sections subject to axial force and biaxial bendingINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 8 2007G. Alfano Abstract We present a numerical procedure, based upon a tangent approach, for evaluating the ultimate limit state (ULS) of reinforced concrete (RC) sections subject to axial force and biaxial bending. The RC sections are assumed to be of arbitrary polygonal shape and degree of connection; furthermore, it is possible to keep fixed a given amount of the total load and to find the ULS associated only with the remaining part which can be increased by means of a load multiplier. The solution procedure adopts two nested iterative schemes which, in turn, update the current value of the tentative ultimate load and the associated strain parameters. In this second scheme an effective integration procedure is used for evaluating in closed form, as explicit functions of the position vectors of the vertices of the section, the domain integrals appearing in the definition of the tangent matrix and of the stress resultants. Under mild hypotheses, which are practically satisfied for all cases of engineering interest, the existence and uniqueness of the ULS load multiplier is ensured and the global convergence of the proposed solution algorithm to such value is proved. An extensive set of numerical tests, carried out for rectangular, L-shaped and multicell sections shows the effectiveness of the proposed solution procedure. Copyright © 2007 John Wiley & Sons, Ltd. [source] Family support: the roles of early years' centresCHILDREN & SOCIETY, Issue 2 2003Rosalind H. Kirk The development of children and the welfare of their parents are closely inter-linked. The study outlined below uses a longitudinal, ecological approach to explore links between different models of early years' centres and the expansion of parents support networks. Over time, parenting stress reduced and well-being improved. Sources of informal and formal support developed and extended. It is argued that all types of centres need to develop a comprehensive approach to child development in which child care and education, as well as family support, are explicit functions. This can promote family resilience as well as social inclusion in communities. Copyright © 2002 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||||||||