Notes from Rome 2018-19

This is the author accepted manuscript. The final version is available from Cambridge University Press via the DOI in this recordThis gazette presents to the reader outside Rome news of recent archaeological activity (in the second half of 2018 and the first half of 2019) gleaned from public lectures, conferences, exhibitions, and newspaper reports.Questa gazetta ha lo scopo di presentare ad un lettore fuori Roma notizie della recente attività archeologica (per la seconda metà del 2018 e la prima metà del 2019), tratte da conferenze, convegni, mostre e relazioni su giornali

Geometric Aspects of Composite Pulses

Unitary operations acting on a quantum system must be robust against systematic errors in control parameters for reliable quantum computing. Composite pulse technique in nuclear magnetic resonance (NMR) realises such a robust operation by employing a sequence of possibly poor quality pulses. In this article, we demonstrate that two kinds of composite pulses, one compensates for a pulse length error in a one-qubit system and the other compensates for a J-coupling error in a twoqubit system, have vanishing dynamical phase and thereby can be seen as geometric quantum gates, which implement unitary gates by the holonomy associated with dynamics of cyclic vectors defined in the text.Comment: 20 pages, 4 figures. Accepted for publication in Philosophical Transactions of the Royal Society

Bridging the Gap Between Commissioning Measures and Large Scale Retrofits in Existing Buildings

Most often commissioning of existing buildings seeks to reduce a building’s energy consumption by implementation of operational changes via the existing equipment. In contrast, large scale capital retrofits seek to make major changes to the systems installed in the building to reach the same goal. The purpose of the investigations presented here is to find energy-saving measures which economically fall between the retro-commissioning measures which typically have very short paybacks and the large scale capital retrofits which typically have significantly longer paybacks. Based on a simulation analysis of three previously retro-commissioned university buildings, it was determined that all three are currently consuming more energy than would be expected under ideal operating conditions. The simulation estimated annual savings potential for the three buildings range from 28-44% of whole building energy consumption. A research level assessment of each has been conducted to identify the reasons why the subject buildings are not operating as efficiently as possible and energy saving measures are presented to bring the buildings as close to ideal operation as possible. This work seeks to determine if an on-site assessment can identify commissioning measures that realize a substantial portion of the indicated savings potential or whether it appears that there are reasons that would preclude commissioning measures from achieving significant savings. If it is not practical to implement commissioning measures due to antiquated controls, missing sensors, or other reasons, these investigations identify rapid payback retrofit measures that achieve as much of the projected savings as possible. The analysis indicates that 30-100% of the estimated savings potential can be realized in the three subject buildings with estimated paybacks of less than 3 years

Designing Robust Unitary Gates: Application to Concatenated Composite Pulse

We propose a simple formalism to design unitary gates robust against given systematic errors. This formalism generalizes our previous observation [Y. Kondo and M. Bando, J. Phys. Soc. Jpn. 80, 054002 (2011)] that vanishing dynamical phase in some composite gates is essential to suppress amplitude errors. By employing our formalism, we naturally derive a new composite unitary gate which can be seen as a concatenation of two known composite unitary operations. The obtained unitary gate has high fidelity over a wider range of the error strengths compared to existing composite gates.Comment: 7 pages, 4 figures. Major revision: improved presentation in Sec. 3, references and appendix adde

Potential Operation and Maintenance (O&M) Savings in the John Sealy North Building at UTMB

The LoanSTAR Monitoring and Analysis Group, Energy Systems Laboratory at Texas A&M University, was requested by University of Texas Medical Branch at Galveston to investigate O&M measures in their five LoanSTAR program buildings. This report describes the suggested O&Ms in John Sealy North Building, a surgical building of 54,494 ft2,which currently spends 502,100 per year on electricity, steam and chilled water. The suggested O&Ms include optimizing the outside air treatment cold deck reset schedule, the cold deck reset schedule and the hot deck reset schedule. These optimized HVAC operation schedules were determined using an analysis involving a simplified HVAC model, which was calibrated against daily data measured by the LoanSTAR program. It is estimated that annual savings of 67,000, or 13% of the annual costs, can be realized using the optimized operation schedules which can be implemented without additional costs. Our analysis indicates that the room comfort levels will not be degraded by these measures

Quantitative analysis of multi-spectral fundus images

We have developed a new technique for extracting histological parameters from multi-spectral images of the ocular fundus. The new method uses a Monte Carlo simulation of the reflectance of the fundus to model how the spectral reflectance of the tissue varies with differing tissue histology. The model is parameterised by the concentrations of the five main absorbers found in the fundus: retinal haemoglobins, choroidal haemoglobins, choroidal melanin, RPE melanin and macular pigment. These parameters are shown to give rise to distinct variations in the tissue colouration. We use the results of the Monte Carlo simulations to construct an inverse model which maps tissue colouration onto the model parameters. This allows the concentration and distribution of the five main absorbers to be determined from suitable multi-spectral images. We propose the use of "image quotients" to allow this information to be extracted from uncalibrated image data. The filters used to acquire the images are selected to ensure a one-to-one mapping between model parameters and image quotients. To recover five model parameters uniquely, images must be acquired in six distinct spectral bands. Theoretical investigations suggest that retinal haemoglobins and macular pigment can be recovered with RMS errors of less than 10%. We present parametric maps showing the variation of these parameters across the posterior pole of the fundus. The results are in agreement with known tissue histology for normal healthy subjects. We also present an early result which suggests that, with further development, the technique could be used to successfully detect retinal haemorrhages

Modelling of edge profiles in pigmented skin lesions

The sharpness of the lesion boundary and the contrast between the lesion and the surrounding skin provide important diagnostic information in the assessment of pigmented skin lesions. This paper presents a new method for computing these parameters by employing an edge model based on a sigmoid function. For each radial profile of the lesion, optimal parameters are found by using an iterative least-squares method. The level and nature of variability of these parameters along the boundary will be correlated with lesion diagnosis in a future study. The method also returns the location equivalent to “zero-crossing” for each profile, thus producing a lesion outline. Additionally, the spread of the pigment beyond the zero-crossing point is computed, thus showing the lesion extent