Mapping constrained optimization problems to quantum annealing with application to fault diagnosis

Current quantum annealing (QA) hardware suffers from practical limitations such as finite temperature, sparse connectivity, small qubit numbers, and control error. We propose new algorithms for mapping boolean constraint satisfaction problems (CSPs) onto QA hardware mitigating these limitations. In particular we develop a new embedding algorithm for mapping a CSP onto a hardware Ising model with a fixed sparse set of interactions, and propose two new decomposition algorithms for solving problems too large to map directly into hardware. The mapping technique is locally-structured, as hardware compatible Ising models are generated for each problem constraint, and variables appearing in different constraints are chained together using ferromagnetic couplings. In contrast, global embedding techniques generate a hardware independent Ising model for all the constraints, and then use a minor-embedding algorithm to generate a hardware compatible Ising model. We give an example of a class of CSPs for which the scaling performance of D-Wave's QA hardware using the local mapping technique is significantly better than global embedding. We validate the approach by applying D-Wave's hardware to circuit-based fault-diagnosis. For circuits that embed directly, we find that the hardware is typically able to find all solutions from a min-fault diagnosis set of size N using 1000N samples, using an annealing rate that is 25 times faster than a leading SAT-based sampling method. Further, we apply decomposition algorithms to find min-cardinality faults for circuits that are up to 5 times larger than can be solved directly on current hardware.Comment: 22 pages, 4 figure

Protection facing exports from sub-Saharan Africa in the EC, Japan, and the United States

The authors address two questions in this report : 1) have exporters in sub - Saharan Africa (SSA) faced more or less protection in Japan, the EC, and the United States than other developing countries and 2) to what extent has protection in those markets constrained SSA's export growth. The authors find that on the whole SSA suffered relatively little from either tariff or nontariff protection in the major industrial markets. In part, this is because they often get a better preferential treatment, especially in the EC, and also, it is because their exports are heavy in primary goods which aregenerally subject to less protection. The authors finally point out that there is no compelling evidence that protection in the major industrial markets has constrained export growth in SSA.Economic Theory&Research,Trade Policy,TF054105-DONOR FUNDED OPERATION ADMINISTRATION FEE INCOME AND EXPENSE ACCOUNT,Environmental Economics&Policies,Export Competitiveness

Tunable Security for Deployable Data Outsourcing

Security mechanisms like encryption negatively affect other software quality characteristics like efficiency. To cope with such trade-offs, it is preferable to build approaches that allow to tune the trade-offs after the implementation and design phase. This book introduces a methodology that can be used to build such tunable approaches. The book shows how the proposed methodology can be applied in the domains of database outsourcing, identity management, and credential management

An assistant for group formation in CSCL based on constraint satisfaction

Group formation is a key aspect in computer-supported collaborative learning, since different characteristics of students might influence the group performance. In this article, we present an assistant that models group formation as a weighted constraint satisfaction problem (WCSP), and considers three students’ features, namely: psychological styles, team roles and social networks. Our WCSP formulation is able to combine constraints and preferences for individuals and groups. This assistant can aid teachers to form groups considering factors such as team role balance and distribution of psychological styles. We report on a pilot study to evaluate the proposal in different scenarios.Sociedad Argentina de Informática e Investigación Operativ

An assistant for group formation in CSCL based on constraint satisfaction

Group formation is a key aspect in computer-supported collaborative learning, since different characteristics of students might influence the group performance. In this article, we present an assistant that models group formation as a weighted constraint satisfaction problem (WCSP), and considers three students’ features, namely: psychological styles, team roles and social networks. Our WCSP formulation is able to combine constraints and preferences for individuals and groups. This assistant can aid teachers to form groups considering factors such as team role balance and distribution of psychological styles. We report on a pilot study to evaluate the proposal in different scenarios.Sociedad Argentina de Informática e Investigación Operativ

Using constraint satisfaction to aid group formation in CSCL

In computer-supported collaborative learning contexts, group formation is a key aspect, since different characteristics of students might influence the group performance. In this article, we present an intelligent assistant that models group formation as a weighted constraint satisfaction problem (WCSP). The assistant takes into account three students´ features, namely: psychological styles, team roles and social networks. The proposed WCSP approach is able to combine constraints and preferences both for individuals and groups. The main goal of the assistant is to aid teachers to form learning groups considering factors such as team role balance and distribution of psychological styles. We also describe a pilot study to evaluate our proposal in different scenarios.Fil: Diaz Pace, Jorge Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Instituto Superior de Ingenieria del Software; ArgentinaFil: Balmaceda, José María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Instituto Superior de Ingenieria del Software; ArgentinaFil: Schiaffino, Silvia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Instituto Superior de Ingenieria del Software; Argentin