Social and Behavioral Sciences Commons^™

Cultural Differences In Business Communication, John N. Hooker

John Hooker

There is no better arena for observing a culture in action than business. Cultures tend to reveal themselves in situations where much is as stake, because it is here that their resources are most needed. Marriage, family obligations, and such stressful experiences as illness and the death of a loved one bring out much of what is distinctive and fundamental in a culture. The same is true of business, because economic survival is at stake. Business practices are shaped by deeply-held cultural attitudes toward work, power, trust, wealth—and communication.

Solving The Incremental Satisfiability Problem, John Hooker

John Hooker

Given a set of clauses in propositional logic that have been found satisfiable, we wish to check whether satisfiability is preserved when the clause set is incremented with a new clause. We describe an efficient implementation of the Davis-Putnam-Loveland algorithm for checking the satisfiability of the original set. We then show how to modify the algorithm for efficient solution of the incremental problem, which is NP-complete. We also report computational results.

Resolution And The Integrality Of Satisfiability Problems, John Hooker

John Hooker

No abstract provided.

Why Business Ethics?, John N. Hooker

John Hooker

Everyone agrees that business managers must understand finance and marketing. But is it necessary for them to study ethics?

Logic-Based Benders Decomposition, John Hooker, G. Ottosson

John Hooker

Benders decomposition uses a strategy of “learning from one’s mistakes.” The aim of this paper is to extend this strategy to a much larger class of problems. The key is to generalize the linear programming dual used in the classical method to an “inference dual.” Solution of the inference dual takes the form of a logical deduction that yields Benders cuts. The dual is therefore very different from other generalized duals that have been proposed. The approach is illustrated by working out the details for propositional satisfiability and 0-1 programming problems. Computational tests are carried out for the latter, but …

Logic-Based Methods For Optimization, John N. Hooker

John Hooker

This tutorial describes a logic-based approach to formulating and solving pure and mixed integer programming problems. It develops logical counterparts for ideas associated with traditional branch-and-cut methods, such as cutting planes, facet-defining cuts, relaxations, etc. The motivations for doing this are a) to exploit the structure of a wide range of problems that are too complex for polyhedral analysis, b) to take advantage of logic processing techniques developed for constraint programming and logic programming, and c) to provide a unified approach to solving the growing number of problems with both qualitative and quantitative elements

Convex Programming Methods For Global Optimization, John N. Hooker

John Hooker

We investigate some approaches to solving nonconvex global optimization problems by convex nonlinear programming methods. We assume that the problem becomes convex when selected variables are fixed. The selected variables must be discrete, or else discretized if they are continuous. We provide a survey of disjunctive programming with convex relaxations, logic-based outer approximation, and logic-based Benders decomposition. We then introduce a branch-and-bound method with convex quasi-relaxations (BBCQ) that can be effective when the discrete variables take a large number of real values. The BBCQ method generalizes work of Bollapragada, Ghattas and Hooker on structural design problems. It applies when the …

Kant And Cultural Relativism, John N. Hooker

John Hooker

We live an age of cultural relativism that asks how universal moral obligation can be justified. Immanuel Kant took up this challenge. His arguments can be reconstructed in a way that makes sense today

Toward Professional Ethics In Business, John N. Hooker

John Hooker

Before a code of professional ethics can be formulated for business managers, it must be understood why management should be considered a profession and what should be its central mission. This paper proposes answers to these questions

Solving Fixed-Charge Network Flow Problems With A Hybrid Optimization And Constraint Programming Approach, Hak-Jin Kim, John N. Hooker

John Hooker

We apply to fixed charge network flow (FCNF) problems a general hybrid solution method that combines constraint programming and linear programming. FCNF problems test the hybrid approach on problems that are already rather well suited for a classical 0–1 model. They are solved by means of a global constraint that generates specialized constraint propagation algorithms and a projected relaxation that can be rapidly solved as a minimum cost network flow problem. The hybrid approach ran about twice as fast as a commercial mixed integer programming code on fixed charge transportation problems with its advantage increasing with problem size. For general …

The Polite And The Rude, John N. Hooker

John Hooker

International managers are aware that business etiquette varies enormously around the world. These minor bits of behavior reflect fundamental differences in culture. By understanding their source, one can not only function with greater confidence but can begin to understand what holds the culture together. Larger behavior patterns that seemed odd or irrational begin to make sense.

Branching Rules For Satisfiability, John N. Hooker, V. Vinay

John Hooker

Recent experience suggests that branching algorithms are among the most attractive for solving propositional satisfiability problems. A key factor in their success is the rule they use to decide on which variable to branch next. We attempt to explain and improve the performance of branching rules with an empirical model-building approach. One model is based on the rationale given for the Jeroslow-Wang rule, variations of which have performed well in recent work. The model is refuted by carefully designed computational experiments. A second model explains the success of the Jeroslow-Wang rule, makes other predictions confirmed by experiment, and leads to …

New Methods For Computing Inferences In First Order Logic, John N. Hooker

John Hooker

Recent improvements in satisfiability algorithms for propositional logic have made partial instantiation methods for first order predicate logic computationally more attractive. Two such methods have been proposed, one by Jeroslow and a hypergraph method for datalog formulas by Gallo and Rago. We show that they are instances of two general approaches to partial instantiation, and we develop these approaches for a large decidable fragment of first order logic (the ∃∀ fragment).

A Postmodern Critique Of Artificial Intelligence, John N. Hooker

John Hooker

I argue that the "postmodern" understanding of language that has developed over the last few decades in Anglo-American philosophy provides the basis for a useful critique of artificial intelligence. This postmodern view corrects an error in the traditional Western conception of language that has led many researchers in AI and cognitive science into taking a rule-based or information-processing approach. Wittgenstein's view that language does not receive its meaning through definition, and Quine's view that neither words nor sentences but only discourse as a whole is the proper unit of meaning, argue against an attempt to formulate rules for understanding language, …

A Constraint Store Based On Multivalued Decision Diagrams, H R. Andersen, Tarik Hadzic, John N. Hooker, Peter Tiedemann

John Hooker

The typical constraint store transmits a limited amount of information because it consists only of variable domains. We propose a richer constraint store in the form of a limited-width multivalued decision diagram (MDD). It reduces to a traditional domain store when the maximum width is one but allows greater pruning of the search tree for larger widths. MDD propagation algorithms can be developed to exploit the structure of particular constraints, much as is done for domain filtering algorithms.We propose specialized propagation algorithms for alldiff and inequality constraints. Preliminary experiments show that MDD propagation solves multiple alldiff problems an order of …

Determining Lower And Upper Bounds On Probabilities Of Atomic Propositions In Sets Of Logical Formulas Represented By Digraphs, K. A. Andersen, John N. Hooker

John Hooker

In this paper we consider the problem of determining lower and upper bounds on probabilities of atomic propositions in sets of logical formulas represented by digraphs. We establish a sharp upper bound, as well as a lower bound that is not in general sharp. We show further that under a certain condition the lower bound is sharp. In that case, we obtain a closed form solution for the possible probabilities of the atomic propositions.

Professional Ethics: Does It Matter Which Hat We Wear?, John N. Hooker

John Hooker

Can two professions impose contradictory obligations? If so, how can both be right? What is professional ethics, anyway, as distinguished from ethics in general?

Cost-Bounded Binary Decision Diagrams For 0-1 Programming, Tarik Hadzic, John N. Hooker

John Hooker

In recent work binary decision diagrams (BDDs) were introduced as a technique for postoptimality analysis for integer programming. In this paper we show that much smaller BDDs can be used for the same analysis by employing cost bounding techniques in their construction.

Some Business-Related Ethical Issues In Engineering, John Hooker

John Hooker

Engineering has always been related to business, but now more than ever. Engineers are increasingly involved in startup companies in which they make business decisions as well as engineering decisions. Even in large firms, highly integrated product development cycles bring engineers into closer contact with marketing and other business people than in years past. Engineers must now think about ethical issues that were once the province of business managers. In addition, the rapid growth of biotechnology and e-commerce has created a new ethical landscape in which engineers must operate.

The aim here is to examine a few of the issues …

Probabilistic Logic For Belief Nets, K. Andersen, John Hooker

John Hooker

We describe how to combine probabilistic logic and Bayesian networks to obtain a new frame-work ("Bayesian logic") for dealing with uncertainty and causal relationships in an expert system. Probabilistic logic, invented by Boole, is a technique for drawing inferences from uncertain propositions for which there are no independence assumptions. A Bayesian network is a "belief net" that can represent complex conditional independence assumptions. We show how to solve inference problems in Bayesian logic by applying Benders decomposition to a nonlinear programming formulation. We also show that the number of constraints grows only linearly with the problem size for a large …

A Filter For The Circuit Constraint, Latife Genç-Kaya, John N. Hooker

John Hooker

We present an incomplete filtering algorithm for the circuit constraint. The filter removes redundant values by eliminating nonhamiltonian edges from the associated graph. We identify nonhamiltonian edges by analyzing a smaller graph with labeled edges that is defined on a separator of the original graph. The complexity of the procedure for each separator S is approximately O(|S|⁵).We found that it identified all infeasible instances and eliminated about one-third of the redundant domain elements in feasible instances.

Succinct Relaxations For Some Discrete Problems, John N. Hooker, Hak-Jin Kim

John Hooker

A discrete problem can be relaxed by taking the continuous relaxation of an integer programming formulation. An equivalent relaxation is obtained by projecting this relaxation onto the original continuous variables. The projection is simple for piecewise linear functions, fixed charge problems and some disjunctive constraints. This allows one to solve much smaller relaxations without sacrificing the quality of bounds. In particular the projected relaxations for some classical network design and warehouse location problems are minimum cost network ow problems, a fact that can dramatically accelerate their solution.

Duality In Optimization And Constraint Satisfaction, John N. Hooker

John Hooker

We show that various duals that occur in optimization and constraint satisfaction can be classified as inference duals, relaxation duals, or both. We discuss linear programming, surrogate, Lagrangean, superadditive, and constraint duals, as well as duals defined by resolution and filtering algorithms. Inference duals give rise to nogood-based search methods and sensitivity analysis, while relaxation duals provide bounds. This analysis shows that duals may be more closely related than they appear, as are surrogate and Lagrangean duals. It also reveals common structure between solution methods, such as Benders decomposition and Davis-Putnam-Loveland methods with clause learning. It provides a framework for …

Mixed Global Constraints And Inference In Hybrid Clp-Ip Solvers, Greger Ottosson, Erlendur Thorsteinsson, John Hooker

John Hooker

The complementing strengths of Constraint (Logic) Programming (CLP) and Mixed Integer Programming (IP) have recently received significant attention. Although various optimization and constraint programming packages at a first glance seem to support mixed models, the modeling and solution techniques encapsulated are still rudimentary. Apart from exchanging bounds for variables and objective, little is known of what constitutes a good hybrid model and how a hybrid solver can utilize the complementary strengths of inference and relaxations. This paper adds to the field by identifying constraints as the essential link between CLP and IP and introduces an algorithm for bidirectional inference through …

Detecting Embedded Horn Structure In Propositional Logic, V. Chandru, John N. Hooker

John Hooker

We show that the problem of finding a maximum renamable Horn problem within a propositional satisfiability problem is NP-hard but can be formulated as a set packing and therefore a maximum clique problem, for which numerous algorithms and heuristics have been developed.

Postoptimality Analysis For Integer Programming Using Binary Decision Diagrams, Tarik Hadzic, John N. Hooker

John Hooker

We show how binary decision diagrams (BDDs) can be used to solve and obtain postoptimality analysis for linear and nonlinear integer programming problems with binary or general integer variables. The constraint set corresponds to a unique reduced BDD that represents all feasible or near-optimal solutions, and in which optimal solutions correspond to certain shortest paths. The BDD can be queried in real time for in-depth postoptimality reasoning. The approach is equally effective for linear and nonlinear problems. There are currently no other methods for obtaining such an analysis, short of repeatedly re-solving the problem. We illustrate the analysis on capital …

Propagating Separable Equalities In An Mdd Store, Tarik Hadzic, John N. Hooker, Peter Tiedemann

John Hooker

We present a propagator that achieves MDD consistency for a separable equality over an MDD (multivalued decision diagram) store in pseudo-polynomial time.We integrate the propagator into a constraint solver based on an MDD store introduced in [1]. Our experiments show that the new propagator provides substantial computational advantage over propagation of two inequality constraints, and that the advantage increases when the maximum width of the MDD store increases.

The Emergence Of A Standards Market: Multiplicity Of Sustainability Standards In The Global Coffee Industry, Juliane Reinecke, Stephan Manning, Oliver Von Hagen

Stephan Manning

The growing number of voluntary standards for governing transnational arenas is presenting standards organizations with a problem. While claiming that they are pursuing shared, overarching objectives, at the same time, they are promoting their own respective standards that are increasingly similar. By developing the notion of ‘standards markets,’ this paper examines this tension and studies how different social movement and industry-driven standards organizations compete as well as collaborate over governance in transnational arenas. Based on an in-depth case study of sustainability standards in the global coffee industry, we find that the ongoing co-existence of multiple standards is being promoted by …

Symposium Report: Findings From The Research Roundtable On The Economic And Community Impact Of Broadband, Edward Feser, John Horrigan, William Lehr

Edward J Feser

In December 2012, a group of experts spanning disciplines and practice in the field of broadband policy met to discuss how the research community can better serve state and local policymakers and other stakeholders. This group of subject matter experts was convened to examine how best to measure the economic impact of state and national broadband deployment and capacity/adoption building efforts. The impetus for the symposium stemmed from the widespread view that there is a deficit of research, standards, and measurements to adequately inform the widely acknowledged view that broadband Internet is a driver of sustainable economic and community development. …

Europa Tra Finanza E Democrazia, Mario Pianta

Mario Pianta

No abstract provided.