Simulating accelerated atoms coupled to a quantum field

We show an analogy between static quantum emitters coupled to a single mode of a quantum field and accelerated Unruh-DeWitt detectors. We envision a way to simulate a variety of relativistic quantum field settings beyond the reach of current computational power, such as high number of qubits coupled to a quantum field following arbitrary non-inertial trajectories. Our scheme may be implemented with trapped ions and circuit QED set-ups.Comment: 5 pages, 2 figures, revtex 4-

Exact Quantum States for all Two-Dimensional Dilaton Gravity Theories

It is shown that the recently obtained quantum wave functionals in terms of the CJZ variables for generic 2d dilaton gravity are equivalent to the previously reported exact quantum wave functionals in geometrical variables. A third representation of these exact quantum states is also presented

Modeling human behavior in user-adaptive systems: recent advances using soft computing techniques

Adaptive Hypermedia systems are becoming more important in our everyday activities and users are expecting more intelligent services from them. The key element of a generic adaptive hypermedia system is the user model. Traditional machine learning techniques used to create user models are usually too rigid to capture the inherent uncertainty of human behavior. In this context, soft computing techniques can be used to handle and process human uncertainty and to simulate human decision-making. This paper examines how soft computing techniques, including fuzzy logic, neural networks, genetic algorithms, fuzzy clustering and neuro-fuzzy systems, have been used, alone or in combination with other machine learning techniques, for user modeling from 1999 to 2004. For each technique, its main applications, limitations and future directions for user modeling are presented. The paper also presents guidelines that show which soft computing techniques should be used according to the task implemented by the application

Cohomological Finiteness Conditions in Bredon Cohomology

We show that any soluble group $G$ of type Bredon-\FP_{\infty} with respect to the family of all virtually cyclic subgroups such that centralizers of infinite order elements are of type \FP_{\infty} must be virtually cyclic. To prove this, we first reduce the problem to the case of polycyclic groups and then we show that a polycyclic-by-finite group with finitely many conjugacy classes of maximal virtually cyclic subgroups is virtually cyclic. Finally we discuss refinements of this result: we only impose the property Bredon-\FP_n for some $n \leq 3$ and restrict to abelian-by-nilpotent, abelian-by-polycyclic or (nilpotent of class 2)-by-abelian groups.Comment: Corrected a mistake in Lemma 2.4 of the previous version, which had an effect on the results in Section 5 (the condition that all centralisers of infinite order elements are of type $FP_\infty$ was added

Strategic Alliances in U.S. Branded Beef Programs

In this paper, we combine concepts from organizational economics to examine supply chain alliances formed to market branded beef products. To illustrate application of the framework, we examine three different types of alliances. We conclude that measuring costs associated with quality attributes have an important role in alliance structure.Agribusiness,

ANALYSIS OF CHANGING METHODS OF VERTICAL COORDINATION IN THE PORK INDUSTRY

This study examines the motivation behind contracts and vertical integration in the pork industry, and simulates the effects of potential improvements in coordination. Incentives related to lowering costs of measuring and sorting hogs, and protecting against opportunistic behavior associated with specific assets, can result in hog quality improvements. A framework for simulating the effects of increased coordination through contracts and vertical integration was developed and used to evaluate potential improvements in leanness. Although simulations suggest only modest changes in pork prices and supplies, gains in consumers' surplus could be substantial for larger demand shifts due to quality improvements.Contracts, Hogs, Lean pork, Simulation model, Vertical coordination, Vertical integration, Industrial Organization, Livestock Production/Industries,

A new N* resonance as a hadronic molecular state

We report our recent work on a hadronic molecule state of the KbarKN system with I=1/2 and J^P=1/2^+. We assume that the Lambda(1405) resonance and the scalar mesons, f_{0}(980), a_{0}(980), are reproduced as quasi-bound states of KbarN and KbarK, respectively. Performing non-relativistic three-body calculations with a variational method for this system, we find a quasibound state of the KbarKN system around 1910 MeV below the three-body breakup threshold. This state corresponds to a new baryon resonance of N* with J^P=1/2^+. We find also that this resonance has the cluster structure of the two-body bound states keeping their properties as in the isolated two-particle systems. We also briefly discuss another hadronic molecular state composed by two Kbar and one N, which corresponds to a Xi^* resonance.Comment: Talk given at Workshop on the Physics of Excited Nucleon -- NSTAR2009, Beijing April 19 - 22, 200