Goto

Collaborating Authors

 Constraint-Based Reasoning


A Heuristic Routing Mechanism Using a New Addressing Scheme

arXiv.org Artificial Intelligence

Current methods of routing are based on network information in the form of routing tables, in which routing protocols determine how to update the tables according to the network changes. Despite the variability of data in routing tables, node addresses are constant. In this paper, we first introduce the new concept of variable addresses, which results in a novel framework to cope with routing problems using heuristic solutions. Then we propose a heuristic routing mechanism based on the application of genes for determination of network addresses in a variable address network and describe how this method flexibly solves different problems and induces new ideas in providing integral solutions for variety of problems. The case of ad-hoc networks is where simulation results are more supportive and original solutions have been proposed for issues like mobility.


Solving Constraint Satisfaction Problems through Belief Propagation-guided decimation

arXiv.org Artificial Intelligence

Message passing algorithms have proved surprisingly successful in solving hard constraint satisfaction problems on sparse random graphs. In such applications, variables are fixed sequentially to satisfy the constraints. Message passing is run after each step. Its outcome provides an heuristic to make choices at next step. This approach has been referred to as `decimation,' with reference to analogous procedures in statistical physics. The behavior of decimation procedures is poorly understood. Here we consider a simple randomized decimation algorithm based on belief propagation (BP), and analyze its behavior on random k-satisfiability formulae. In particular, we propose a tree model for its analysis and we conjecture that it provides asymptotically exact predictions in the limit of large instances. This conjecture is confirmed by numerical simulations.


Constraint-Based Random Stimuli Generation for Hardware Verification

AI Magazine

We report on random stimuli generation for hardware verification at IBM as a major applica-tion of various artificial intelligence technologies, including knowledge representation, expert systems, and constraint satisfaction. For more than a decade we have developed several related tools, with huge payoffs. Research and development around this application are still thriving, as we continue to cope with the ever-increasing complexity of modern hardware systems and demanding business environments.


Constraint-Based Random Stimuli Generation for Hardware Verification

AI Magazine

Once the rules are formulated, This knowledge base is developed and maintained how does the stimuli generator ensure by knowledge engineers who are verification that all user-defined and validity rules, and as experts. Test templates are written by many expert knowledge rules as possible, are verification engineers who implement the test satisfied? How can the generator produce many significantly different tests from the plan. The generic engine, developed by software same test template? Finally, how is all this done engineers, accepts the architecture model, in an efficient manner as to not obstruct the expert knowledge, and test template and generates verification process?


Theory of Finite or Infinite Trees Revisited

arXiv.org Artificial Intelligence

We present in this paper a first-order axiomatization of an extended theory $T$ of finite or infinite trees, built on a signature containing an infinite set of function symbols and a relation $\fini(t)$ which enables to distinguish between finite or infinite trees. We show that $T$ has at least one model and prove its completeness by giving not only a decision procedure, but a full first-order constraint solver which gives clear and explicit solutions for any first-order constraint satisfaction problem in $T$. The solver is given in the form of 16 rewriting rules which transform any first-order constraint $\phi$ into an equivalent disjunction $\phi$ of simple formulas such that $\phi$ is either the formula $\true$ or the formula $\false$ or a formula having at least one free variable, being equivalent neither to $\true$ nor to $\false$ and where the solutions of the free variables are expressed in a clear and explicit way. The correctness of our rules implies the completeness of $T$. We also describe an implementation of our algorithm in CHR (Constraint Handling Rules) and compare the performance with an implementation in C++ and that of a recent decision procedure for decomposable theories.


An Intelligent Personal Assistant for Task and Time Management

AI Magazine

We describe an intelligent personal assistant that has been developed to aid a busy knowledge worker in managing time commitments and performing tasks. The design of the system was motivated by the complementary objectives of (1) relieving the user of routine tasks, thus allowing her to focus on tasks that critically require human problem-solving skills, and (2) intervening in situations where cognitive overload leads to oversights or mistakes by the user. The system draws on a diverse set of AI technologies that are linked within a Belief-Desire-Intention (BDI) agent system. Although the system provides a number of automated functions, the overall framework is highly user centric in its support for human needs, responsiveness to human inputs, and adaptivity to user working style and preferences.


Soft constraint abstraction based on semiring homomorphism

arXiv.org Artificial Intelligence

The semiring-based constraint satisfaction problems (semiring CSPs), proposed by Bistarelli, Montanari and Rossi \cite{BMR97}, is a very general framework of soft constraints. In this paper we propose an abstraction scheme for soft constraints that uses semiring homomorphism. To find optimal solutions of the concrete problem, the idea is, first working in the abstract problem and finding its optimal solutions, then using them to solve the concrete problem. In particular, we show that a mapping preserves optimal solutions if and only if it is an order-reflecting semiring homomorphism. Moreover, for a semiring homomorphism $\alpha$ and a problem $P$ over $S$, if $t$ is optimal in $\alpha(P)$, then there is an optimal solution $\bar{t}$ of $P$ such that $\bar{t}$ has the same value as $t$ in $\alpha(P)$.


Calculating Valid Domains for BDD-Based Interactive Configuration

arXiv.org Artificial Intelligence

In these notes we formally describe the functionality of Calculating Valid Domains from the BDD representing the solution space of valid configurations. The formalization is largely based on the CLab configuration framework.


Nonparametric inference of prior probabilities from Bayes-optimal behavior

Neural Information Processing Systems

We discuss a method for obtaining a subject's a priori beliefs from his/her behavior in a psychophysics context, under the assumption that the behavior is (nearly) optimal from a Bayesian perspective. The method is nonparametric in the sense that we do not assume that the prior belongs to any fixed class of distributions (e.g., Gaussian).


AI@50: We Are Golden!

AI Magazine

It is now mature enough to collaborate of a cybernetic meadow productively with its sister disciplines, where mammals and computers realizing the dream of ubiquitous computational live together in mutually intelligence. Several of AI's subdisciplines have wellestablished of our field, at Dartmouth College in 1956, is a They are practitioners while most of our failures are along the lines of achieving successful results later than of Kuhn's "normal" science--filling in boxes we had predicted in our youthful exuberance. Many of the philosophers who lectured us on Other parts of our field seem to be in a what we would never be able to achieve have state of perpetual revolution. Perhaps most gone strangely silent. All this struggle and cybernetics and pattern recognition; however, debate demonstrates the health of the field.