Reaction Curve (reaction + curve)

Distribution by Scientific Domains


Selected Abstracts


Ground response curves for rock masses exhibiting strain-softening behaviour

INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 13 2003
E. Alonso
Abstract A literature review has shown that there exist adequate techniques to obtain ground reaction curves for tunnels excavated in elastic-brittle and perfectly plastic materials. However, for strain-softening materials it seems that the problem has not been sufficiently analysed. In this paper, a one-dimensional numerical solution to obtain the ground reaction curve (GRC) for circular tunnels excavated in strain-softening materials is presented. The problem is formulated in a very general form and leads to a system of ordinary differential equations. By adequately defining a fictitious ,time' variable and re-scaling some variables the problem is converted into an initial value one, which can be solved numerically by a Runge,Kutta,Fehlberg method, which is implemented in MATLAB environment. The method has been developed for various common particular behaviour models including Tresca, Mohr,Coulomb and Hoek,Brown failure criteria, in all cases with non-associative flow rules and two-segment piecewise linear functions related to a principal strain-dependent plastic parameter to model the transition between peak and residual failure criteria. Some particular examples for the different failure criteria have been run, which agree well with closed-form solutions,if existing,or with FDM-based code results. Parametric studies and specific charts are created to highlight the influence of different parameters. The proposed methodology intends to be a wider and general numerical basis where standard and newly featured behaviour modes focusing on obtaining GRC for tunnels excavated in strain-softening materials can be implemented. This way of solving such problems has proved to be more efficient and less time consuming than using FEM- or FDM-based numerical 2D codes. Copyright 2003 John Wiley & Sons, Ltd. [source]


STRATEGIC INVESTMENT IN A NEW MIXED MARKET WITH LABOR-MANAGED AND PROFIT-MAXIMIZING FIRMS

METROECONOMICA, Issue 4 2008
Article first published online: 1 AUG 200, Kazuhiro Ohnishi
ABSTRACT This paper examines a continuous-time mixed model of the strategic investment decisions of a labor-managed income-per-worker-maximizing firm and a profit-maximizing firm in a new mixed market and constructs a set of perfect equilibria of the continuous-time mixed model. The paper shows that there exists a particular equilibrium in which neither firm invests to its steady-state reaction curve. The paper also finds that the existence of the particular equilibrium depends on each firm's being able to respond quickly to its rival's investment and that the particular equilibrium is profitable for each firm. [source]


On the Effectiveness of the Lifetime,Employment,Contract Policy

THE MANCHESTER SCHOOL, Issue 6 2002
Kazuhiro Ohnishi
This paper examines a subgame perfect equilibrium when one of two duopolists executes a lifetime,employment,contract policy, which is a strategic commitment that generates kinks in the reaction curve, by using a two,stage quantity,setting model. The purpose of the paper is to show concretely in what kinds of cases the policy is effective. [source]


Effect of variation in photoperiodic response on diapause induction and developmental time in the willow leaf beetle, Plagiodera versicolora

ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2000
Michihiro Ishihara
Abstract The willow leaf beetle, Plagiodera versicolora (Coleoptera: Chrysomelidae) overwinters in adult diapause. In this study, the photoperiodic responses for diapause induction and developmental time were examined in the Ishikari (Hokkaido, Japan) population of P. versicolora. All females entered reproductive diapause under short daylength (L10:D14), but 31.7% of females did not enter diapause under long daylength (L16:D8). The developmental time from oviposition to adult emergence was significantly longer at L10:D14 than that at L16:D8. Norm of reaction curves illustrated variation among families in the photoperiodic responses for diapause induction and for developmental time. ANOVA indicated significant family photoperiod interactions in the developmental time. At L16:D8, developmental time was positively correlated with the incidence of diapause in females. This means that a female having a longer developmental time tends to have a longer critical photoperiod. Such variation may be maintained by differences in selection pressures on the growth rate and the critical photoperiod for diapause induction between univoltine and bivoltine genotypes because Ishikari is located in a transitional area between populations with univoltine and bivoltine life cycles. [source]


Ground response curves for rock masses exhibiting strain-softening behaviour

INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 13 2003
E. Alonso
Abstract A literature review has shown that there exist adequate techniques to obtain ground reaction curves for tunnels excavated in elastic-brittle and perfectly plastic materials. However, for strain-softening materials it seems that the problem has not been sufficiently analysed. In this paper, a one-dimensional numerical solution to obtain the ground reaction curve (GRC) for circular tunnels excavated in strain-softening materials is presented. The problem is formulated in a very general form and leads to a system of ordinary differential equations. By adequately defining a fictitious ,time' variable and re-scaling some variables the problem is converted into an initial value one, which can be solved numerically by a Runge,Kutta,Fehlberg method, which is implemented in MATLAB environment. The method has been developed for various common particular behaviour models including Tresca, Mohr,Coulomb and Hoek,Brown failure criteria, in all cases with non-associative flow rules and two-segment piecewise linear functions related to a principal strain-dependent plastic parameter to model the transition between peak and residual failure criteria. Some particular examples for the different failure criteria have been run, which agree well with closed-form solutions,if existing,or with FDM-based code results. Parametric studies and specific charts are created to highlight the influence of different parameters. The proposed methodology intends to be a wider and general numerical basis where standard and newly featured behaviour modes focusing on obtaining GRC for tunnels excavated in strain-softening materials can be implemented. This way of solving such problems has proved to be more efficient and less time consuming than using FEM- or FDM-based numerical 2D codes. Copyright 2003 John Wiley & Sons, Ltd. [source]