3,148 research outputs found

    Probably Approximately Correct Nash Equilibrium Learning

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    We consider a multi-agent noncooperative game with agents' objective functions being affected by uncertainty. Following a data driven paradigm, we represent uncertainty by means of scenarios and seek a robust Nash equilibrium solution. We treat the Nash equilibrium computation problem within the realm of probably approximately correct (PAC) learning. Building upon recent developments in scenario-based optimization, we accompany the computed Nash equilibrium with a priori and a posteriori probabilistic robustness certificates, providing confidence that the computed equilibrium remains unaffected (in probabilistic terms) when a new uncertainty realization is encountered. For a wide class of games, we also show that the computation of the so called compression set - a key concept in scenario-based optimization - can be directly obtained as a byproduct of the proposed solution methodology. Finally, we illustrate how to overcome differentiability issues, arising due to the introduction of scenarios, and compute a Nash equilibrium solution in a decentralized manner. We demonstrate the efficacy of the proposed approach on an electric vehicle charging control problem.Comment: Preprint submitted to IEEE Transactions on Automatic Contro

    P.L.E.A.T.-Preventing Lymphocele Ensuring Absorption Transperitoneally: A Robotic Technique

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    OBJECTIVE: To reduce the risk of symptomatic lymphocele after robotic pelvic lymph node dissection (PLND), we present a novel technique, preventing lymphocele ensuring absorption transperitoneally (P.L.E.A.T.), where the peritoneum is "pleated" along its midline, leaving 2 lateral openings and allowing lymphatic fluid to drain away from the pelvis and into the abdomen. MATERIALS AND METHODS: We analyzed a single-surgeon series of PLNDs during robotic radical prostatectomy, comparing 195 "standard" PLNDs (in which the peritoneum was "re-approximated" or left completely open) with 176 cases in which P.L.E.A.T. was performed. RESULTS: In the group without P.L.E.A.T., 8 cases of symptomatic (grade 653, according to the Clavien-Dindo Classification) lymphoceles (4.1%) were recorded. Only 1 patient in the P.L.E.A.T. group complained of symptoms because of a lymphocele (P\u2009=\u2009.039). No patient reported complications because of the procedure. CONCLUSION: The P.L.E.A.T. technique is a fast, easy-to-perform, and safe method of reducing the risk of symptomatic lymphocele after transperitoneal robotic PLND

    The Green Economy and Job Creation: Inclusion of People with Disabilities

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    The percentage of total employment associated with green goods and services has increased in the United States over the past several years, presenting employment opportunities in a number of related emerging fields. As employment options arise to provide green goods and services, people with disabilities should have equitable employment opportunities in this growth sector of the American economy. A focused strategy to train and engage people with disabilities in the green economy can provide a talented and largely untapped segment of the U.S. workforce, a greater opportunity to participate in this growing employment sector than previously realized

    New instruments and technologies for Cultural Heritage survey: full integration between point clouds and digital photogrammetry

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    In the last years the Geomatic Research Group of the Politecnico di Torino faced some new research topics about new instruments for point cloud generation (e.g. Time of Flight cameras) and strong integration between multi-image matching techniques and 3D Point Cloud information in order to solve the ambiguities of the already known matching algorithms. ToF cameras can be a good low cost alternative to LiDAR instruments for the generation of precise and accurate point clouds: up to now the application range is still limited but in a near future they will be able to satisfy the most part of the Cultural Heritage metric survey requirements. On the other hand multi-image matching techniques with a correct and deep integration of the point cloud information can give the correct solution for an "intelligent" survey of the geometric object break-lines, which are the correct starting point for a complete survey. These two research topics are strictly connected to a modern Cultural Heritage 3D survey approach. In this paper after a short analysis of the achieved results, an alternative possible scenario for the development of the metric survey approach inside the wider topic of Cultural Heritage Documentation is reporte

    Archaeological site monitoring: UAV photogrammetry can be an answer

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    During archaeological excavations it is important to monitor the new excavated areas and findings day by day in order to be able to plan future excavation activities. At present, this daily activity is usually performed by using total stations, which survey the changes of the archaeological site: the surveyors are asked to produce day by day draft plans and sections which allow archaeologists to plan their future activities. The survey is realized during the excavations or just at the end of every working day and drawings have to be produced as soon as possible in order to allow the comprehension of the work done and to plan the activities for the following day. By using this technique, all the measurements, even those not necessary for the day after, have to be acquired in order to avoid a ‘loss of memory'. A possible alternative to this traditional approach is aerial photogrammetry, if the images can be acquired quickly and at a taken distance able to guarantee the necessary accuracy of a few centimeters. Today the use of UAVs (Unmanned Aerial Vehicles) can be considered a proven technology able to acquire images at distances ranging from 4 m up to 20 m: and therefore as a possible monitoring system to provide the necessary information to the archaeologists day by day. The control network, usually present at each archaeological site, can give the stable control points useful for orienting a photogrammetric block acquired by using an UAV equipped with a calibrated digital camera and a navigation control system able to drive the aircraft following a pre-planned flight scheme. Modern digital photogrammetric software can solve for the block orientation and generate a DSM automatically, allowing rapid orthophoto generation and the possibility of producing sections and plans. The present paper describes a low cost UAV system realized by the research group of the Politecnico di Torino and tested on a Roman villa archaeological site located in Aquileia (Italy), a well-known UNESCO WHL site. The results of automatic orientation and orthophoto production are described in terms of their accuracy and the completeness of information guaranteed for archaeological site excavation managemen

    Malaria eradication in Mexico: Some historico-parasitological views oncold war, deadly fevers by Marcos Cueto, Ph.D

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    This review of Professor Marcos Cueto's Cold War Deadly Fevers: Malaria Eradication in Mexico, 1955–1975 discusses some of the historical, sociological, political and parasitological topics included in Dr. Cueto's superbly well-informed volume. The reviewer, a parasitologist, follows the trail illuminated by Dr. Cueto through the foundations of the malaria eradication campaign; the release in Mexico of the first postage stamp in the world dedicated to malaria control; epidemiological facts on malarial morbidity and mortality in Mexico when the campaign began; the emergence of problem areas that impeded eradication; considerations on mosquitoes and malaria transmission in Mexico; the role of business and society in malaria eradication; the results of the campaign; the relationship between malaria and poverty; and the parasitological lessons to be learned from the history of malaria eradication campaigns. Dr. Cueto's excellent and well-informed exploration of malaria – not merely as a disease but as a social, economic and human problem – makes this book required reading

    Frailty and elderly in urology: Is there an impact on post-operative complications?

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    INTRODUCTION: Frailty used as predictive tool is still not carried out in daily practice, although many studies confirm the great clinical importance of the frailty syndrome in surgical outcomes. There is no standardized method of measuring the physiological reserves of older surgical patients. The aim of this study was to analyze a cohort of older urological patients according to various frailty indices, in order to evaluate whether they are predictors of post-operative complications after urological procedures. MATERIAL AND METHODS: This is a prospective observational study on 78 consecutive older ( 6570 years) patients, subjected to major urological (both endoscopic and 'open surgical') procedures. Frailty was defined according to the Edmonton Frail Scale. Several risk models and biochemical parameters were evaluated. Post-operative outcomes were surgical and medical complications, mortality and rehospitalisation within 3 months. RESULTS: An overall prevalence of frailty of 21.8% was found. Patients with complications were frailer than those without complications (univariate analysis), considering both total patients (p = 0.002) and endoscopic (p = 0.04) and 'open surgical' patients (p = 0.013). However, in multivariate analysis, a significant correlation was not found between all frailty indices tested and the risk of major complications. Limitation of the study: the small sample size (lack of statistical power), although this is a prospective study focused on older urological patients. CONCLUSIONS: New urology-tailored pre-operative assessment tools may prove beneficial when calculating the risks/benefits of urological procedures, so that objective data can guide surgical decision- making and patient counselling. Further large clinical studies specifically focusing on elderly in urology will be needed
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