117 research outputs found
Product variety and reliability
No full textMurthy et al. [Murthy DNP, Rausand M, Virtanen S. Investment in new product reliability, Reliability Engineering & System Safety (accepted for publication)l proposed an approach to decide on product reliability in the context of new product development and identified two tasks for execution as part of the overall process. In this paper, we focus on the first task-determining the product reliability requirements
Using Cox's proportional hazard models to implement optimal strategies: An example from behavioural ecology
No full textSimple behavioural rules, or “rules of thumb”, which lead to behaviour that closely approximates an optimal strategy, have generated a lot of recent interest in the field of foraging behaviour. In this paper, we derive rules of thumb from a stochastic simulation model in which the foragers behave optimally. We use a particular biological system: the patch leaving behaviour of a parasitoid. We simulate parasitoids whose patch leaving behaviour is determined by a stochastic dynamic programming (SDP) model, while allowing parasitoids to make mistakes in their estimation of host density when arriving in a patch. We use Cox's proportional hazards models to obtain statistical rules of thumb from the simulated behaviour. This represents the first use of a proportional hazard approximation to generate rules of thumb from a complex optimal strategy.http://www.elsevier.com/wps/find/journaldescription.cws_home/623/description#descriptio
Implicit vector equilibrium problems with applications
No full textLet X and Y be Hausdorff topological vector spaces, K a nonempty, closed, and convex subset of X, C: K--> 2(Y) a point-to-set mapping such that for any x is an element of K, C(x) is a pointed, closed, and convex cone in Y and int C(x) not equal 0. Given a mapping g : K --> K and a vector valued bifunction f : K x K - Y, we consider the implicit vector equilibrium problem (IVEP) of finding x* is an element of K such that f (g(x*), y) is not an element of - int C(x) for all y is an element of K. This problem generalizes the (scalar) implicit equilibrium problem and implicit variational inequality problem. We propose the dual of the implicit vector equilibrium problem (DIVEP) and establish the equivalence between (IVEP) and (DIVEP) under certain assumptions. Also, we give characterizations of the set of solutions for (IVP) in case of nonmonotonicity, weak C-pseudomonotonicity, C-pseudomonotonicity, and strict C-pseudomonotonicity, respectively. Under these assumptions, we conclude that the sets of solutions are nonempty, closed, and convex. Finally, we give some applications of (IVEP) to vector variational inequality problems and vector optimization problems. (C) 2003 Elsevier Science Ltd. All rights reserved
Three-point boundary value problems for second-order, ordinary, differential equations
No full textWe establish existence results for solutions to three-point boundary value problems for nonlinear, second-order, ordinary differential equations with nonlinear boundary conditions. (C) 2001 Elsevier Science Ltd. All rights reserved
Warranty data analysis for assessing product reliability
No full textIn consumer electronics, the high degree of innovation has resulted in a constant flow of new generations of products with ever increasing functionality. In this chapter, a real case is described in which field data from CD players are used with the aim of preventing the recurrence of ‘old’ problems in a new generation of digital video recorders. The difficulties in using warranty data for this purpose are highlighted
Study of linear discrete time systems with state variable constraints
No full textIn this paper we discuss the property of reachability and controllability for a linear discrete time system, with the trajectory constrained to satisfy a state variable inequality constraint of the form
A note on block replacement policy
No full textIn this note we study block replacement policy with a modification to include stock level at the beginning of the cycle
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