5,752 research outputs found
Set-based design of mechanical systems with design robustness integrated
This paper presents a method for parameter design of mechanical products based on a set-based approach. Set-based concurrent engineering emphasises on designing in a multi-stakeholder environment with concurrent involvement of the stakeholders in the design process. It also encourages flexibility in design through communication in terms of ranges instead of fixed point values and subsequent alternative solutions resulting from intersection of these ranges. These alternative solutions can then be refined and selected according to the designersâ preferences and clientsâ needs. This paper presents a model and tools for integrated flexible design that take into account the manufacturing variations as well as the design objectives for finding inherently robust solutions using QCSP transformation through interval analysis. In order to demonstrate the approach, an example of design of rigid flange coupling with a variable number of bolts and a choice of bolts from ISO M standard has been resolved and demonstrated
Scalable Parallel Numerical CSP Solver
We present a parallel solver for numerical constraint satisfaction problems
(NCSPs) that can scale on a number of cores. Our proposed method runs worker
solvers on the available cores and simultaneously the workers cooperate for the
search space distribution and balancing. In the experiments, we attained up to
119-fold speedup using 256 cores of a parallel computer.Comment: The final publication is available at Springe
An Analysis of Arithmetic Constraints on Integer Intervals
Arithmetic constraints on integer intervals are supported in many constraint
programming systems. We study here a number of approaches to implement
constraint propagation for these constraints. To describe them we introduce
integer interval arithmetic. Each approach is explained using appropriate proof
rules that reduce the variable domains. We compare these approaches using a set
of benchmarks. For the most promising approach we provide results that
characterize the effect of constraint propagation. This is a full version of
our earlier paper, cs.PL/0403016.Comment: 44 pages, to appear in 'Constraints' journa
Efficient Solving of Quantified Inequality Constraints over the Real Numbers
Let a quantified inequality constraint over the reals be a formula in the
first-order predicate language over the structure of the real numbers, where
the allowed predicate symbols are and . Solving such constraints is
an undecidable problem when allowing function symbols such or . In
the paper we give an algorithm that terminates with a solution for all, except
for very special, pathological inputs. We ensure the practical efficiency of
this algorithm by employing constraint programming techniques
Hull Consistency Under Monotonicity
International audienceWe prove that hull consistency for a system of equations or inequalities can be achieved in polynomial time providing that the underlying functions are monotone with respect to each variable. This result holds including when variables have multiple occurrences in the expressions of the functions, which is usually a pitfall for interval-based contractors. For a given constraint, an optimal contractor can thus be enforced quickly under monotonicity and the practical significance of this theoretical result is illustrated on a simple example
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