Absolute Dynamical Limit to Cooling Weakly-Coupled Quantum Systems

Cooling of a quantum system is limited by the size of the control forces that are available (the "speed" of control). We consider the most general cooling process, albeit restricted to the regime in which the thermodynamics of the system is preserved (weak coupling). Within this regime, we further focus on the most useful control regime, in which a large cooling factor, and good ground-state cooling can be achieved. We present a control protocol for cooling, and give clear structural arguments, as well as strong numerical evidence, that this protocol is globally optimal. From this we obtain simple expressions for the limit to cooling that is imposed by the speed of control.Comment: 4 pages, Revetex4-1, 2 png figure

A procedure model for evaluating IT-security investments

The security of information systems is a vital factor for companies nowadays. In order to achieve an adequate level of security, a variety of distinct measures is available, ranging from technical meas-ures to organizational measures. In near past suitable methods for decision support especially for the assessment of the profitability of IT-security investments have been developed. But integrated procedure models for a complete it-security controlling can neither be found in literature nor in practice. With this article, we propose a method framework that enables the analysis of the results of alternative security investments from a process-oriented perspective. As a basis, we have conducted an in-deep analysis of the state-of-the-art in the fields of IT-Business-Alignment and IT-security management in order to identify suitable concepts for the framework. A special focus lies on the requirements of IT-security controlling of critical business processes.Безпека інформаційних систем у теперішній час є життєво важливим фактором для компаній. Багато різних вимірів, від технічних до організаційних, є доступними для досягнення прийнятного рівня безпеки. У недалекому минулому було розроблено методи підтримки прийняття рішень при оцінюванні прибутковості інвестицій у IT-безпеку. Проте інтегральні процедурні моделі для повного управління IT-безпекою до цього часу не знайдені – ані у літературі, ані на практиці. У цієї статті ми пропонуємо середовище, яке дає можливість аналізувати результати альтернативних інвестицій у безпеку з точки зору, орієнтованої на процеси. Ми здійснили поглиблений аналіз сучасного стану справ у галузях синхронізації IT та бізнесу та управління IT-безпекою з метою ідентифікувати прийнятні концепції для цього середовища. Спеціальну увагу приділено вимогам до IT-безпеки критичних бізнес-процесів

Polarization Observables for Two-Pion Production off the Nucleon

We develop polarization observables for the processes $\gamma N\to\pi\pi N$ and $\pi N\to\pi\pi N$, using both a helicity and hybrid helicity-transversity basis. Such observables are crucial if processes that produce final states consisting of a spin-1/2 baryon and two pseudoscalar mesons are to be fully exploited for baryon spectroscopy. We derive relationships among the observables, as well as inequalities that they must satisfy. We also discuss the observables that must be measured in `complete' experiments, and briefly examine the prospects for measurement of some of these observables in the near future.Comment: 20 pages, using revtex

Designing Web-enabled services to provide damage estimation maps caused by natural hazards

The availability of building stock inventory data and demographic information is an important requirement for risk assessment studies when attempting to predict and estimate losses due to natural hazards such as earthquakes, storms, floods or tsunamis. The better this information is provided, the more accurate are predictions on damage to structures and lifelines and the better can expected impacts on the population be estimated. When a disaster strikes, a map is often one of the first requirements for answering questions related to location, casualties and damage zones caused by the event. Maps of appropriate scale that represent relative and absolute damage distributions may be of great importance for rescuing lives and properties, and for providing relief. However, this type of maps is often difficult to obtain during the first hours or even days after the occurrence of a natural disaster. The Open Geospatial Consortium Web Services (OWS) Specifications enable access to datasets and services using shared, distributed and interoperable environments through web-enabled services. In this paper we propose the use of OWS in view of these advantages as a possible solution for issues related to suitable dataset acquisition for risk assessment studies. The design of web-enabled services was carried out using the municipality of Managua (Nicaragua) and the development of damage and loss estimation maps caused by earthquakes as a first case study. Four organizations located in different places are involved in this proposal and connected through web services, each one with a specific role

Reexamination of decoherence in quantum walks on the hypercube

The effect of decoherence on the continuous-time quantum walk on the hypercube is revisited. Previously, an exact solution was found for a decoherence model that preserved the effective tensor-product form of the dynamics. Here a new model is presented, inspired by perfect quantum state transfer in qubit networks. A perturbative solution is found for the dynamics of this model which is not of a tensor-product form. In contrast to previous results, the hitting probability has a lower bound that is independent of the hypercube dimension.Comment: 8 pages, 4 figures, revised title and text for PR