In this work, we present the design and implementation of an ultra-low latency Deep Reinforcement Learning (DRL) FPGA based accelerator for addressing hard real-time Mixed Integer Programming ...problems. The accelerator exhibits ultra-low latency performance for both training and inference operations, enabled by training-inference parallelism, pipelined training, on-chip weights and replay memory, multi-level replication-based parallelism and DRL algorithmic modifications such as distribution of training over time. The design principles can be extended to support hardware acceleration for other relevant DRL algorithms (embedding the experience replay technique) with hard real time constraints. We evaluate the accuracy of the accelerator in a task offloading and resource allocation problem stemming from a Mobile Edge Computing (MEC/5G) scenario. The design has been implemented on a Xilinx Zynq Ultrascale+ MPSoC ZCU104 evaluation kit using High Level Synthesis. The accelerator achieves near optimal performance and exhibits a 10-fold decrease in training-inference execution latency when compared to a high-end CPU-based implementation.
Smart grid technology is the next step to the evolution of classical power grids, providing robustness, reliability, and security throughout the network, enabling real-time management and control. To ...achieve these goals, distributed computing (microgrid concept) and intelligent control algorithms, tailored to the nature and needs of the network under study, are necessary. To deal with the vast diversity of power grids, being able to capture the dynamics of any given network, and create tools for network analysis, apparatus testing, and power grid management, an automatic design framework for real-time power system simulators is needed. In this article, a prototype of this approach is presented, employing Field Programmable Gate Array (FPGA) platforms due to their reconfigurability that enables low-power, low-latency, and high-performance designs, as a first attempt towards an open source platform, compatible with the majority of hardware design suites. It comprises two major parts: (i) a user-oriented section, built in Matlab/Simulink; and (ii) a hardware-oriented section, written in Matlab and Very High Speed Integrated Circuit (VHSIC)-Hardware Description Language (VHDL) code. To verify its functionality, two test power networks were given in a schematic format, analyzed through Matlab code and turned into dedicated hardware simulators with the aid of the VHDL template. Then, simulation results from Simulink and the prototype were compared for error estimation. The results show the prototype’s successful implementation with minimal resources utilization, high performance and low latency in the order of nanoseconds in Xilinx 6- and 7-series FPGAs, therefore proving its modularity and efficient use in many different scenarios, meeting low-latency/real-time requirements while enabling further smart grid research.
Edge Cloud is providing unprecedented opportunities for IoT and WAMS (Wide Area Monitoring Systems) in electrical grid operation. It is an orchestrated environment able to address low latency events ...through appropriate edge-cloud computing configurations.Transient State Estimation (TSE) is a key monitoring tool for capturing a reliable knowledge of the Smart Grid status in real-time, given the impediments introduced by the increasing penetration of Distributed Energy Resources in the energy mix. Frequency response anomalies, large scale transients, and voltage swings can be captured by TSE for real time or post failure data analytics. This work presents a cloud edge framework for the efficient calculation of TSE which, albeit its benefits, demands high computational resources at the edge (close to the measurement units) along with ultra low latency communications. The framework enables TSE as a service through the coordination of Virtual Machines (VMs) running on virtualized infrastructure and other non-virtualized physical nodes. In order to support the stringent time requirements, part of the TSE is offloaded to dedicated hardware acceleration units (FPGA). The proposed TSE framework is validated using an IEEE 30-bus, and the results show a significant superiority in terms of total latency compared to conventional cloud and edge deployments.
Metafruticicola is a diverse land snail genus inhabiting the north-eastern Mediterranean region from S Albania to Israel. In this study, we describe Metafruticicola kavafis sp. nov., a new species ...for science from Kasos Island. We also focus on the reproductive system of steno-endemic species and subspecies of the genus from small islands of the Aegean Archipelago, whose anatomy was previously completely unknown. These species are M. crassicosta, M. pieperi, M. coartata gemina and M. nicosiana conciliatrix. For the latter subspecies, only the outlines of the genitalia were previously given. Additionally, we investigated in detail for the first time the genital anatomy of M. nicosiana nicosiana from Cyprus. Hitherto, information on the genital apparatus of this subspecies was based on sparse data derived from sexually immature specimens. These new anatomical data contribute to a plethora of controversies concerning the subgeneric division of Metafruticicola, which was based solely on conchological features and especially the microsculpture of the teleoconch. We suggest that the current subgeneric division of the genus should be abandoned.
Tetralogy of Fallot (ToF) is one of the most common cyanotic congenital heart defects. We sought to summarize all available data regarding the epidemiology and perioperative outcomes of syndromic ToF ...patients. A PRISMA-compliant systematic literature review of PubMed and Cochrane Library was performed. Twelve original studies were included. The incidence of syndromic ToF was 15.3% (
n
= 549/3597). The most prevalent genetic syndromes were 22q11.2 deletion (47.8%; 95% CI 43.4–52.2) and trisomy 21 (41.9%; 95% CI 37.7–46.3). Complete surgical repair was performed in 75.2% of the patients (
n
= 161/214; 95% CI 69.0–80.1) and staged repair in 24.8% (
n
= 53/214; 95 CI 19.4–30.9). Relief of RVOT obstruction was performed with transannular patch in 64.7% (
n
= 79/122; 95% CI 55.9–72.7) of the patients, pulmonary valve-sparing technique in 17.2% (
n
= 21/122; 95% CI 11.5–24.9), and RV-PA conduit in 18.0% (
n
= 22/122; 95% CI 12.1–25.9). Pleural effusions were the most common postoperative complications (
n
= 28/549; 5.1%; 95% CI 3.5–7.3). Reoperations were performed in 4.4% (
n
= 24/549; 95% CI 2.9–6.4) of the patients. All-cause mortality rate was 9.8% (
n
= 51/521; 95% CI 7.5–12.7). Genetic syndromes are seen in approximately 15% of ToF patients. Long-term survival exceeds 90%, suggesting that surgical management should be dictated by anatomy regardless of genetics.
Abstract
Background
The traditional technique of gastrointestinal reconstruction of the esophagus after esophagectomy presents plenty of complications. Hence, tissue engineering has been introduced ...as an effective artificial alternative with potentially fewer complications. Three types of esophageal scaffolds have been used in experimental studies so far. The aim of our meta-analysis is to present the postoperative outcomes after esophageal replacement with artificial scaffolds and the investigation of possible factors that affect these outcomes.
Methods
The present proportional meta-analysis was designed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and A MeaSurement Tool to Assess systematic Reviews guidelines. We searched Medline, Scopus, Clinicaltrials.gov, EMBASE, Cochrane Central Register of Controlled Trials CENTRAL, and Google Scholar databases from inception until February 2020.
Results
Overall, 32 studies were included that recruited 587 animals. The pooled morbidity after esophageal scaffold implantation was 53.4% (95% CI = 36.6–70.0%). The pooled survival interval was 111.1 days (95% CI = 65.5–156.8 days). Graft stenosis (46%), postoperative dysphagia (15%), and anastomotic leak (12%) were the most common complications after esophageal scaffold implantation. Animals that underwent an implantation of an artificial scaffold in the thoracic part of their esophagus presented higher survival rates than animals that underwent scaffold implantation in the cervical or abdominal part of their esophagus (P < 0.001 and P = 0.011, respectively).
Conclusion
Tissue engineering seems to offer an effective alternative for the repair of esophageal defects in animal models. Nevertheless, issues like graft stenosis and lack of motility of the esophageal scaffolds need to be addressed in future experimental studies before scaffolds can be tested in human trials.
Diffuse esophageal leiomyomatosis (DEL) is a rare disorder characterized by benign hypertrophy of esophageal smooth muscle cells. No rigorous summary of available evidence on how to best manage these ...patients exists.
To define the clinical features and outcomes of pediatric patients with DEL.
A systematic literature search of the PubMed and Cochrane databases was performed with respect to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement (end-of-search date: October 6, 2018). The algorithm: "esophageal leiomyomatosis AND (children OR pediatric*)" was implemented.
Thirty-five studies including a total of 58 patients were analyzed. The female:male ratio was 1.45:1. Mean patient age was 8.54 ± 4.67 years. The most common disease manifestations were dysphagia and gastrointestinal symptoms (90.0%, 95% confidence interval CI: 78.2-96.1), followed by failure to thrive (57.9%, 95% CI: 36.2-76.9) and pulmonary symptoms (56.4%, 95% CI: 41.0-70.7). Alport syndrome (AS) was seen in 57.7% (95% CI: 44.2-70.1) of the patients. The most commonly implemented procedure was esophagectomy (85.2%;
= 46/54; 95% CI: 73.1-92.6) with gastric transposition (37.8%;
= 17/45; 95% CI: 25.1-52.4). Postoperative complications developed in 33.3% (
= 15/45; 95% CI: 21.3-48) of the patients. All-cause mortality was 7.0% (95% CI: 2.3-17.2) and disease-specific mortality was 3.5% (95% CI: 0.3-12.6).
DEL is an uncommon condition that typically occurs in the setting of AS. Esophagectomy with gastric transposition is the mainstay of treatment. Although complications develop in one-third of the patients, mortality rates are low.
Acute esophageal necrosis (AEN) is a rare entity with multifactorial etiology, usually presenting with signs of upper gastrointestinal bleeding.
To systematically review all available data on ...demographics, clinical features, outcomes and management of this medical condition.
A systematic literature search was performed with respect to the PRISMA statement (end-of-search date: October 24, 2018). Data on the study design, interventions, participants and outcomes were extracted by two independent reviewers.
Seventy-nine studies were included in this review. Overall, 114 patients with AEN were identified, of whom 83 were males and 31 females. Mean patient age was 62.1 ± 16.1. The most common presenting symptoms were melena, hematemesis or other manifestations of gastric bleeding (85%). The lower esophagus was most commonly involved (92.9%). The most widely implemented treatment modality was conservative treatment (75.4%), while surgical or endoscopic intervention was required in 24.6% of the cases. Mean overall follow-up was 66.2 ± 101.8 d. Overall 29.9% of patients died either during the initial hospital stay or during the follow-up period. Gastrointestinal symptoms on presentation Odds ratio 3.50 (1.09-11.30),
= 0.03 and need for surgical or endoscopic treatment surgical: Odds ratio 1.25 (1.03-1.51),
= 0.02; endoscopic: Odds ratio 1.4 (1.17-1.66),
< 0.01 were associated with increased odds of complications. A sub-analysis separating early versus late cases (after 2006) revealed a significantly increased frequency of surgical or endoscopic intervention (9.7 %
30.1% respectively,
= 0.04).
AEN is a rare condition with controversial pathogenesis and unclear optimal management. Although the frequency of surgical and endoscopic intervention has increased in recent years, outcomes have remained the same. Therefore, further research work is needed to better understand how to best treat this potentially lethal disease.
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