The road to fully integrated DC-DC conversion via the switched-capacitor approach

This paper provides a perspective on progress toward realization of efficient, fully integrated dc-dc conversion and regulation functionality in CMOS platforms. In providing a comparative assessment between the inductor-based and switched-capacitor approaches, the presentation reviews the salient features in effectiveness in utilization of switch technology and in use and implementation of passives. The analytical conclusions point toward the strong advantages of the switched-capacitor (SC) approach with respect to both switch utilization and much higher energy densities of capacitors versus inductors. The analysis is substantiated with a review of recently developed and published integrated dc-dc converters of both the inductor-based and SC types. © 2012 IEEE

Per-Core DVFS with Switched-Capacitor Converters for Energy Efficiency in Manycore Processors

Integrating multiple power converters on-chip improves energy efficiency of manycore architectures. Switched-capacitor (SC) dc-dc converters are compatible with conventional CMOS processes, but traditional implementations suffer from limited conversion efficiency. We propose a dynamic voltage and frequency scaling scheme with SC converters that achieves high converter efficiency by allowing the output voltage to ripple and having the processor core frequency track the ripple. Minimum core energy is achieved by hopping between different converter modes and tuning body-bias voltages. A multicore processor model based on a 28-nm technology shows conversion efficiencies of 90% along with over 25% improvement in the overall chip energy efficiency

Discrete R-symmetries and Anomaly Universality in Heterotic Orbifolds

We study discrete R-symmetries, which appear in 4D low energy effective field theory derived from hetetoric orbifold models. We derive the R-symmetries directly from geometrical symmetries of orbifolds. In particular, we obtain the corresponding R-charges by requiring that the couplings be invariant under these symmetries. This allows for a more general treatment than the explicit computations of correlation functions made previously by the authors, including models with discrete Wilson lines, and orbifold symmetries beyond plane-by-plane rotational invariance. Surprisingly, for the cases covered by earlier explicit computations, the R-charges differ from the previous result. We study the anomalies associated with these R-symmetries, and comment on the results.Comment: 21 pages, 2 figures. Minor changes, typos corrected. Matches JHEP published versio

A Method to Improve the Early Stages of the Robotic Process Automation Lifecycle

The robotic automation of processes is of much interest to organizations. A common use case is to automate the repetitive manual tasks (or processes) that are currently done by back-office staff through some information system (IS). The lifecycle of any Robotic Process Automation (RPA) project starts with the analysis of the process to automate. This is a very time-consuming phase, which in practical settings often relies on the study of process documentation. Such documentation is typically incomplete or inaccurate, e.g., some documented cases never occur, occurring cases are not documented, or documented cases differ from reality. To deploy robots in a production environment that are designed on such a shaky basis entails a high risk. This paper describes and evaluates a new proposal for the early stages of an RPA project: the analysis of a process and its subsequent design. The idea is to leverage the knowledge of back-office staff, which starts by monitoring them in a non-invasive manner. This is done through a screen-mousekey- logger, i.e., a sequence of images, mouse actions, and key actions are stored along with their timestamps. The log which is obtained in this way is transformed into a UI log through image-analysis techniques (e.g., fingerprinting or OCR) and then transformed into a process model by the use of process discovery algorithms. We evaluated this method for two real-life, industrial cases. The evaluation shows clear and substantial benefits in terms of accuracy and speed. This paper presents the method, along with a number of limitations that need to be addressed such that it can be applied in wider contexts.Ministerio de Economía y Competitividad TIN2016-76956-C3-2-

Une course sans répit : l’évolution des paramètres des candidats à la résidence en oto-rhino-laryngologie – chirurgie cervico-faciale au fil du temps

Background: There has been an increasing number of Canadian medical graduates who have gone unmatched in the residency selection process. Medical students have been engaging in extracurricular activities outside the formal curriculum which may help to distinguish themselves from their peers in the selection process. To understand how competitiveness in residency selection shapes applicant demographic characteristics and behaviours, this study set out to explore the demographic characteristics and prevalence of reported extra-curricular activities by applicants to Canadian Otolaryngology – Head & Neck Surgery (OTL-HNS) residency across time. Methods: A retrospective, descriptive study reviewed specific sections of the curriculum vitae (CV) of applicants to OTL-HNS programs in Canada.  These sections were self-reported, and included research productivity, involvement in volunteer and leadership activities, membership in associations, and honours or awards granted.  Data was quantified and analyzed descriptively. Results: Between 2013 to 2017, a total of 267 applicants reported a median of 12.6 research publications, 9.6 volunteer activities, six leadership activities, six association memberships and 9.8 honours/awards. Applicants were younger over time, with proportions of applicants over 30 years old decreasing from 56% in 2013 to 9% in 2017. Conclusion: Applicants to Canadian OTL-HNS residency programs are reporting consistently high numbers of extracurricular activities and were of increasingly younger ages. Medical students are investing significant time and energy to pursue these activities which are above and beyond the formal curriculum, possibly contributing to decreased diversity in applicants for competitive residencies, increasing the likelihood of misrepresentation in residency applications, and likely contributing to medical student burnout.Contexte : De plus en plus de diplômés en médecine canadiens demeurent non jumelés à l’issue du processus de sélection des résidents. Certains font des activités hors programme afin de se distinguer de leurs pairs dans le processus de sélection. Pour comprendre comment la compétition dans la sélection de résidents influence les caractéristiques démographiques et les comportements des candidats, cette étude visait à explorer l’évolution des caractéristiques démographiques et la prévalence d’activités hors programme déclarées par les candidats à la résidence en oto-rhino-laryngologie – chirurgie cervico-faciale (ORL-CCF) à travers le temps. Méthodes : Dans le cadre d’une étude rétrospective et descriptive, nous avons parcouru des sections pertinentes du curriculum vitae (CV) des candidats aux programmes d'oto-rhino-laryngologie et chirurgie cervico-faciale au Canada. Ces sections étaient auto-déclarées et comprenaient les activités de recherche, la participation à des activités de bénévolat et de leadership, l'appartenance à des associations et les prix et distinctions obtenus. Les données ont été quantifiées et analysées de manière descriptive. Résultats : Entre 2013 et 2017, un total de 267 candidats ont déclaré une médiane de 12,6 publications de recherche, 9,6 activités de bénévolat, 6 activités de leadership, 6 adhésions à des associations et 9,8 prix et distinctions. Au fil du temps, on observe que les candidats sont de plus en plus jeunes ; ainsi, la proportion de candidats âgés de 30 ans et plus a diminué de 56 % en 2013 à 9 % en 2017. Conclusion : Les candidats aux programmes de résidence en ORL-CCF au Canada déclarent d’une année à l’autre un nombre élevé d'activités hors programme et sont de plus en plus jeunes. Les étudiants en médecine investissent beaucoup de temps et d'énergie dans ces activités qui vont au-delà du programme d'études officiel. Cela pourrait nuire à la diversité des candidats aux programmes de résidence fortement contingentés, augmenter la probabilité de fausses déclarations dans les demandes de résidence et probablement contribuer à l'épuisement professionnel des étudiants en médecin

A RISC-V Vector Processor With Simultaneous-Switching Switched-Capacitor DC-DC Converters in 28 nm FDSOI

This work demonstrates a RISC-V vector microprocessor implemented in 28 nm FDSOI with fully integrated simultaneous-switching switched-capacitor DC-DC (SC DC-DC) converters and adaptive clocking that generates four on-chip voltages between 0.45 and 1 V using only 1.0 V core and 1.8 V IO voltage inputs. The converters achieve high efficiency at the system level by switching simultaneously to avoid charge-sharing losses and by using an adaptive clock to maximize performance for the resulting voltage ripple. Details about the implementation of the DC-DC switches, DC-DC controller, and adaptive clock are provided, and the sources of conversion loss are analyzed based on measured results. This system pushes the capabilities of dynamic voltage scaling by enabling fast transitions (20 ns), simple packaging (no off-chip passives), low area overhead (16%), high conversion efficiency (80%-86%), and high energy efficiency (26.2 DP GFLOPS/W) for mobile devices

Thermal production of axino Dark Matter

We reconsider thermal production of axinos in the early universe, adding: a) missed terms in the axino interaction; b) production via gluon decays kinematically allowed by thermal masses; c) a precise modeling of reheating. We find an axino abunance a few times larger than previous computations.Comment: 6 pages, 2 figures. Final version, to appear on JHE

Fragments of the earliest land plants

The earliest fossil evidence for land plants comes from microscopic dispersed spores. These microfossils are abundant and widely distributed in sediments, and the earliest generally accepted reports are from rocks of mid-Ordovician age (Llanvirn, 475 million years ago). Although distribution, morphology and ultrastructure of the spores indicate that they are derived from terrestrial plants, possibly early relatives of the bryophytes, this interpretation remains controversial as there is little in the way of direct evidence for the parent plants. An additional complicating factor is that there is a significant hiatus between the appearance of the first dispersed spores and fossils of relatively complete land plants (megafossils): spores predate the earliest megafossils (Late Silurian, 425 million year ago) by some 50 million years. Here we report the description of spore-containing plant fragments from Ordovician rocks of Oman. These fossils provide direct evidence for the nature of the spore-producing plants. They confirm that the earliest spores developed in large numbers within sporangia, providing strong evidence that they are the fossilized remains of bona fide land plants. Furthermore, analysis of spore wall ultrastructure supports liverwort affinities

Assessment of potential cardiotoxic side effects of mitoxantrone in patients with multiple sclerosis

Previous studies showed that mitoxantrone can reduce disability progression in patients with multiple sclerosis (MS). There is, however, concern that it may cause irreversible cardiomyopathy with reduced left ventricular (LV) ejection fraction (EF) and congestive heart failure. The aim of this prospective study was to investigate cardiac side effects of mitoxantrone by repetitive cardiac monitoring in MS patients. The treatment protocol called for ten courses of a combined mitoxantrone (10 mg/m(2) body surface) and methylprednisolone therapy. Before each course, a transthoracic echocardiogram was performed to determine the LV end-diastolic diameter, the end-systolic diameter and the fractional shortening; the LV-EF was calculated. Seventy-three patients participated (32 males; age 48 +/- 12 years, range 20-75 years; 25 with primary progressive, 47 with secondary progressive and 1 with relapsing-remitting MS) who received at least four courses of mitoxantrone. Three of the 73 patients were excluded during the study (2 patients discontinued therapy; 1 patient with a previous history of ischemic heart disease developed atrial fibrillation after the second course of mitoxantrone). The mean cumulative dose of mitoxantrone was 114.0 +/- 33.8 mg. The mean follow-up time was 23.4 months (range 10-57 months). So far, there has been no significant change in any of the determined parameters (end-diastolic diameter, end-systolic diameter, fractional shortening, EF) over time during all follow-up investigations. Mitoxantrone did not cause signs of congestive heart failure in any of the patients. Further cardiac monitoring is, however, needed to determine the safety of mitoxantrone after longer follow-up times and at higher cumulative doses. Copyright (C) 2005 S. Karger AG, Basel