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Displacement Model (displacement + model)

Distribution by Scientific Domains

Business, Economics, Finance and Accounting	75%

Selected Abstracts

Non-local damage model based on displacement averaging

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 1 2005
M. Jirásek
Abstract Continuum damage models describe the changes of material stiffness and strength, caused by the evolution of defects, in the framework of continuum mechanics. In many materials, a fast evolution of defects leads to stress,strain laws with softening, which creates serious mathematical and numerical problems. To regularize the model behaviour, various generalized continuum theories have been proposed. Integral-type non-local damage models are often based on weighted spatial averaging of a strain-like quantity. This paper explores an alternative formulation with averaging of the displacement field. Damage is assumed to be driven by the symmetric gradient of the non-local displacements. It is demonstrated that an exact equivalence between strain and displacement averaging can be achieved only in an unbounded medium. Around physical boundaries of the analysed body, both formulations differ and the non-local displacement model generates spurious damage in the boundary layers. The paper shows that this undesirable effect can be suppressed by an appropriate adjustment of the non-local weight function. Alternatively, an implicit gradient formulation could be used. Issues of algorithmic implementation, computational efficiency and smoothness of the resolved stress fields are discussed. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Distribution of gains from research and promotion in the presence of market power

AGRIBUSINESS : AN INTERNATIONAL JOURNAL, Issue 3 2003
Michael K. Wohlgenant
This article evaluates how marginal returns to producers from promotion and research are affected when market intermediaries have market power in the retail market. Using an equilibrium displacement model, the relative importance of market power is evaluated for a "typical" food-processing industry, and the empirical analysis focuses on how much profits from advertising, off-farm research, and farm research are affected by a one dollar increase in check-off funds, assuming equal efficiency in funds spent at each level of the marketing channel. The empirical analysis systematically considers alternative values of the underlying structural parameters of the model using Monte Carlo simulations to generate confidence intervals of marginal returns from each alternative use of the funds. Important findings are that the results with market power are indistinguishable from those obtained under pure competition and the results are most affected by input substitutability. [EconLit citations: L660]. © 2003 Wiley Periodicals, Inc. Agribusiness 19: 301,314, 2003. [source]

Potential Payoff from R&D in the Coconut Industry of North Sulawesi, Indonesia

ASIAN ECONOMIC JOURNAL, Issue 1 2010
Benjamin Henderson
D58; O13; O18 The coconut industry of North Sulawesi, one of the primary coconut-producing provinces of Indonesia, is dominated by a small number of products that are primarily exported overseas. As they only comprise a small share of the global coconut product export market, demand for coconut products from North Sulawesi is generally very elastic. Conversely, the supply of coconuts is highly inelastic, especially in the short to medium term. Hence, small shifts in supply and demand lead to large fluctuations in farmer incomes. In this context, an equilibrium displacement model is used to examine the intra-industry consequences of R&D investments in farm productivity and product development. These investments are assessed in terms of the producer surplus benefits that they generate. [source]

Optimal Generic Advertising with a Rationed Related Good: The Case of Canadian Beef and Chicken Markets

CANADIAN JOURNAL OF AGRICULTURAL ECONOMICS, Issue 2 2002
J. A. L. Cranfield
An optimal advertising rule is derived for a good sold in an open market (beef) when a related substitute good (chicken) is production rationed and whose imports are subject to trade restrictions. Such a rule is developed using a multi-market equilibrium displacement model that reflects demand interrelatedness, open trade of the advertised good (beef), with rationed production and restricted trade of the related good (chicken). The optimal rule nests earlier optimal advertising rules under a variety of conditions. Results underscore the importance of accounting for cross-product advertising effects. When these effects are present (absent), the optimal generic beef advertising intensity in Canada is shown to fall (rise) with elimination of supply management in Canada's chicken sector. L'auteur dérive une règie sur l'optimisation de la publicité pour un produit vendu sur un marché libre (b,uf) en présence d'un produit de substitution rationné dont on restreint les importations. Pour parvenir à une telle règie, l'auteur a utilisé un modèle de déplacement du point d'équilibre sur un marché multiple illustrant les liens entre la demande des produits concernés, le libre-échange du produit faisant l'objet de la publicité (b,uf) et la restriction de la production et des importations du produit apparenté (poulet). La règie d'optimisation englobe les règles antérieures sur l'optimisation de la publicité dans diverses situations. Les résultats soulignent qu'il est important de prendre en compte les retombées de la publicité sur les autres produits. Au Canada, en présence (absence) de telles retombées, le degré optimal de publicité générique sur le b,uf diminue (augmente) avec l'abolition de la gestion de l'offre de poulet. [source]