We provide a reformulation of the constraint hierarchies (CHs) framework based on the notion of error indicators. Adapting the generalized view of local consistency in semiring-based constraint satisfaction problems (SCSPs), we define constraint hierarchy k-consistency (CH-k-C) and give a CH-2-C enforcement algorithm. We demonstrate how the CH-2-C algorithm can be seamlessly integrated into the...

Recent approaches to integrity enforcement in active databases suggest not only to check constraint violations by triggers but also to utilize triggers to perform inconsistency repair actions. However, for sophisticated reactions these approaches often require refinements of already derived integrity maintaining and inconsistency repairing triggers. We argue that analyzing and specifying reacti...

We study “causality” relationships in Concurrent Constraint Programming: what is observed is not just the conjunction of constraints deposited in the store, but also the causal dependencies between these constraints. We describe a denotational semantics for cc that is fully-abstract with respect to observing this “causality” relation on constraints. This semantics preserves more fine-grained st...

Many languages have support for automatic type inference. But when inference fails, the reported error messages can be unhelpful, highlighting a code location far from the source of the problem. Several lines of work have emerged proposing error reports derived from correcting sets: a set of program points that, when fixed, produce a well-typed program. Unfortunately, these approaches are tight...

The paper considers several optimization problem statements for signal sparse reconstruction problems. We tested performance of AORDA Portfolio Safeguard (PSG) package with different problem formulations. We solved several medium-size test problems with cardinality functions: (a) minimize L1-error of regression subject to a constraint on cardinality of the solution vector; (b) minimize cardinal...

It is known that the unit-norm constraint for equation-error based system identification is superior to the monic constraint since it produces consistent estimates for white measurement noise and also presents better approximation properties in reduced-order cases. Here, a new algorithm for unit-norm equation-error adaptive filtering is proposed. This scheme is inspired by the constrained optim...

The aim of this work is to investigate the variational discretization and mixed finite element methods for optimal control problem governed by semi linear parabolic equations with integral constraint. The state and co-state are approximated by the lowest order Raviart-Thomas mixed finite element spaces and the control is not discreted. Optimal error estimates in L2 are established for the state...

The quadratic constraint equation error (QCEE) method was proposed by Ho and Chan to achieve bias removal for the equation error adaptive IIR filters. However, this approach is limited to slow convergence in estimation when a small step size is used; large step sizes lead to significant misadjustment. This correspondence presents a variable step size (VSS) technique to greatly improve the QCEE ...

Experience using constraint programming to solve real-life problems has shown that nding an eecient solution to the problem often requires experimentation with diierent constraint solvers or even building a problem-speciic constraint solver. HAL is a new constraint logic programming language expressly designed to facilitate this process. It provides a well-deened solver interface, mutable globa...

Recently a constant-norm constraint equationerror method was proposed to solve the bias problem in adaptive IIR filtering. However, the method adopts a fixed step-size and thus results in slow convergence for a small step-size and significant misadjustment error for a large step-size. In this paper, we propose a variable step-size (VSS) algorithm that greatly improves convergence properties of ...