Time-dependent topological systems: A study of the Bott index

The Bott index is an index that discerns among pairs of unitary matrices that can or cannot be approximated by a pair of commuting unitary matrices. It has been successfully employed to describe the approximate integer quantization of the transverse conductance of a system described by a short-range, bounded and spectrally gapped Hamiltonian on a finite two dimensional lattice on a torus and to describe the invariant of the Bernevig- Hughes-Zhang model even with disorder. This paper shows the constancy in time of the Bott index and the Chern number related to the time-evolved Fermi projection of a thermodynamically large system described by a short-range and time-dependent Hamiltonian that is initially gapped. The general situation of a ramp of a time-dependent perturbation is considered, a section is dedicated to time-periodic perturbations.Comment: 8 pages, partial rephrasing of title and sections' title. Partial rewriting of the introduction. Results unchanged. Accepted by PR

On the equivalence of the Bott index and the Chern number on a torus, and the quantization of the Hall conductivity with a real space Kubo formula

The equivalence of the Bott index and the Chern number is established in the thermodynamic limit for a gapped, short ranged and bounded Hamiltonian on a two dimensional torus of linear size $L$. A Kubo formula as an exact operatorial identity is provided in real space and used to show the quantization of the transverse conductance within corrections of order $L^{-1}$. In doing so the physical foundations of the theory that introduces the Bott index in the realm of condensed matter as proposed by Hastings and Loring in J. Math. Phys. (51), 015214, (2010) and Annals of Physics 326 (2011) 1699-1759 are recalled.Comment: 10 pages. Corrected typos. Added references. Added acknowledgement

Developing Guidelines for Two-Dimensional Model Review and Acceptance

Two independent modelers ran two hydraulic models, SRH-2D and HEC-RAS 2D. The models were applied to the Lakina River (MP 44 McCarthy Road) and to Quartz Creek (MP 0.7 Quartz Creek Road), which approximately represent straight and bend flow conditions, respectively. We compared the results, including water depth, depth averaged velocity, and bed shear stress, from the two models for both modelers. We found that the extent and density of survey data were insufficient for Quartz Creek. Neither model was calibrated due to the lack of basic field data (i.e., discharge, water surface elevation, and sediment characteristics). Consequently, we were unable to draw any conclusion about the accuracy of the models. Concerning the time step and the equations used (simplified or full) to solve the momentum equation in the HEC-RAS 2D model, we found that the minimum time step allowed by the model must be used if the diffusion wave equation is used in the simulations. A greater time step can be used if the full momentum equation is used in the simulations. We developed a set of guidelines for reviewing model results, and developed and provided a two-day training workshop on the two models for ADOT&PF hydraulic engineers

Energy performance assessment of HVAC systems by inspection and monitoring

The paper discusses the collection and processing of energy performance data as part of the inspection of HVAC systems, aimed at identifying technically feasible and cost-effective Energy Conservation Opportunities (ECO), as required by EPBD. Case studies developed by the HARMONAC project have shown that low-cost or no-cost ECO's - mostly related to system operation and management - can be identified with an effective system monitoring. Building Management Systems (BMS) may be a powerful tool for this task, provided their HW and SW architecture is designed with adequate attention to energy monitoring. Dedicated instrumentation - such as electricity meters and temperature loggers - may also be employed as an alternative / integration to BMS monitoring. The paper also discusses the application of data analysis tools - such as "carpet plots" and "energy signatures" - to the identification of component malfunctioning, control problems, inadequate maintenance, or system schedule optimization, and to the evaluation of achieved energy saving

An empirical study of argumentation schemes in deliberative dialogue

Publisher PD

Financial market regulation in the wake of financial crises: the historical experience

The focus of the present volume - which originates from a workshop held at the Bank of Italy on 16 and 17 April 2009 - is the regulatory response given to financial crises in the past, across countries. Alongside the scholarly interest of such a review its aim is also to offer some insights that may be useful in re-designing regulation in the present time of distress. Financial crises have been examined under many perspectives, including that of regulatory failures. The studies assembled in this volume, which touch on a significant array of countries, can be viewed as part of a historical survey on this issue. The basic question is whether regulatory responses form a pattern, and more specifically, whether they tend to be biased with respect to an optimum, however defined. In the end, rather than finding one pattern of response, we were able to identify the "disturbances" which most often enter the post-crisis decisional process. The awareness of such factors, and some knowledge of their functioning, are instrumental in understanding (for academics) and in governing (for policy makers) the response to major financial crises.Financial crises, financial regulation, economic history

Monitoring Winter Flow Conditions on the Ivishak River, Alaska

The Sagavanirktok River, a braided river on the Alaska North Slope, flows adjacent to the trans-Alaska pipeline for approximately 100 miles south of Prudhoe Bay. During an unprecedented flooding event in mid-May 2015, the pipeline was exposed in an area located approximately 20 miles south of Prudhoe Bay. The Ivishak River is a main tributary of the Sagavanirktok River, but little is known about its water flow characteristics and contribution to the Sagavanirktok River, especially in winter and during spring breakup. To gather this information, we installed water level sensors on two main tributaries of the Ivishak River (Upper Ivishak and Saviukviayak rivers), early in winter season 2016–2017, in open-water channels that showed promise as locations for long-term gauging stations. Our ultimate goal was to find a location for permanent deployment of water level sensors. By February, the first sites chosen were ice covered, so two additional sensors, one on each river, were deployed in different locations. Some of the sensors were lost (i.e., carried away by the current or buried under a thick layer of sediments). Water level data gathered from the sensors showed a maximum change of 1.07 m. Winter discharge measurements indicate a 44% reduction between February and April 2017. A summer discharge measurement shows a 430% increase from winter to summer

Chromosome positioning is largely unaffected in lymphoblastoid cell lines containing emerin or A-type lamin mutations

Gene-poor human chromosomes are reproducibly found at the nuclear periphery in proliferating cells. There are a number of inner nuclear envelope proteins that may have roles in chromosome location and anchorage, e.g. emerin and A-type lamins. In the last decade, a number of diseases associated with tissue degeneration and premature aging have been linked with mutations in lamin A or emerin. These are termed laminopathies, withmutations in emerin causing Emery–Dreifuss muscular dystrophy. Despite highly aberrant nuclear distributions of A-type lamins and emerin in lymphoblastoid cell lines derived from patients with emerin or lamin A mutations, little or no change in chromosome location was detected