Jan Kraj cek posed the following problem: Is there is a generalization result in the theory of real closed elds of the form: If A(1 + + 1) (n occurrences of 1) is provable in length k for all n 2 !, then (8x)A(x) is provable? It is argued that the answer to this question depends on the particular formulation of the \theory of real closed elds." Four distinct formulations are investigated with r...

A big power is facing a small power that may have developed weapons of mass destruction. The small power can create strategic ambiguity by refusing arms inspections. We study the impact of strategic ambiguity on arms proliferation and welfare. Strategic ambiguity is a substitute for actually acquiring weapons: ambiguity reduces the incentive for the small power to invest in weapons, which reduc...

his background paper explores the technical pathways by which states might acquire nuclear, chemical, and biological weapons and the systems to deliver them. It also assesses the level of effort, commitment, and resources required to mount such developments. The paper is a companion to the OTA report Proliferation of Weapons of Mass Destruction: Assessing the Risks, which describes what nuclear...

The urgency of the environmental debate has renewed the interest in the application of integrated models of urban land use and transportation. In the United States new legislation inspired by growing environmental awareness such as the Intermodal Surface Transportation Efficiency Act of 1991 requires that transportation planning must consider the interaction between transportation and land use ...

BACKGROUND (1) Weapons of Mass Destruction (WMD)—chemical, biological, radiological, and nuclear agents (CBRN)—in the possession of hostile states or terrorists represent one of the greatest security challenges facing the United States. An attack utilizing WMD potentially could cause mass casualties, compromise critical infrastructure, adversely affect our economy, and inflict social and psycho...

In this paper, we introduce a community detection approach from heterogeneous multi-relational network which incorporate the multiple types of objects and relationships, derived from a bibliographic networks. The proposed approach performs firstly by constructing the relation context family (RCF) to represent the different objects and relations in the multi-relational bibliographic networks usi...

We introduce a broad family of decision trees, Composite Trees, whose leaf classifiers are selected out of a hypothesis set composed of p subfamilies with different complexities. We prove new data-dependent learning guarantees for this family in the multi-class setting. These learning bounds provide a quantitative guidance for the choice of the hypotheses at each leaf. Remarkably, they depend o...

....................................................................................................................... ii ACKNOWLEDGMENTS ................................................................................................. iii TABLE OF CONTENTS................................................................................................... iv LIST OF PUBLICATION AND ABSTRACTS .....

• Most failures of engineering systems result from the gradual and irreversible accumulation of damage: – A process known as Degradation • We examine degradation processes that can be monitored using sensor technology and that result in – Degradation Signals • We focus on – Modeling degradation signals under time-varying environmental conditions. – Computing the distribution of residual life un...

When do elections induce politicians to act as delegates, and when do they induce them to act as trustees? To answer this question, we develop a model of political accountability in which politicians vary in both their policy preferences and their competence. We show that elections are more likely to induce politicians to behave as trustees when uncertainty about incumbent policy preferences is...