Interoperability Among Unmanned Maritime Vehicles: Review and First In-field Experimentation

Complex maritime missions, both above and below the surface, have traditionally been carried out by manned surface ships and submarines equipped with advanced sensor systems. Unmanned Maritime Vehicles (UMVs) are increasingly demonstrating their potential for improving existing naval capabilities due to their rapid deployability, easy scalability, and high reconfigurability, offering a reduction in both operational time and cost. In addition, they mitigate the risk to personnel by leaving the man far-from-the-risk but in-the-loop of decision making. In the long-term, a clear interoperability framework between unmanned systems, human operators, and legacy platforms will be crucial for effective joint operations planning and execution. However, the present multi-vendor multi-protocol solutions in multi-domain UMVs activities are hard to interoperate without common mission control interfaces and communication protocol schemes. Furthermore, the underwater domain presents significant challenges that cannot be satisfied with the solutions developed for terrestrial networks. In this paper, the interoperability topic is discussed blending a review of the technological growth from 2000 onwards with recent authors' in-field experience; finally, important research directions for the future are given. Within the broad framework of interoperability in general, the paper focuses on the aspect of interoperability among UMVs not neglecting the role of the human operator in the loop. The picture emerging from the review demonstrates that interoperability is currently receiving a high level of attention with a great and diverse deal of effort. Besides, the manuscript describes the experience from a sea trial exercise, where interoperability has been demonstrated by integrating heterogeneous autonomous UMVs into the NATO Centre for Maritime Research and Experimentation (CMRE) network, using different robotic middlewares and acoustic modem technologies to implement a multistatic active sonar system. A perspective for the interoperability in marine robotics missions emerges in the paper, through a discussion of current capabilities, in-field experience and future advanced technologies unique to UMVs. Nonetheless, their application spread is slowed down by the lack of human confidence. In fact, an interoperable system-of-systems of autonomous UMVs will require operators involved only at a supervisory level. As trust develops, endorsed by stable and mature interoperability, human monitoring will be diminished to exploit the tremendous potential of fully autonomous UMVs

Risk factors associated with adverse fetal outcomes in pregnancies affected by Coronavirus disease 2019 (COVID-19): a secondary analysis of the WAPM study on COVID-19.

Objectives To evaluate the strength of association between maternal and pregnancy characteristics and the risk of adverse perinatal outcomes in pregnancies with laboratory confirmed COVID-19. Methods Secondary analysis of a multinational, cohort study on all consecutive pregnant women with laboratory-confirmed COVID-19 from February 1, 2020 to April 30, 2020 from 73 centers from 22 different countries. A confirmed case of COVID-19 was defined as a positive result on real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay of nasal and pharyngeal swab specimens. The primary outcome was a composite adverse fetal outcome, defined as the presence of either abortion (pregnancy loss before 22 weeks of gestations), stillbirth (intrauterine fetal death after 22 weeks of gestation), neonatal death (death of a live-born infant within the first 28 days of life), and perinatal death (either stillbirth or neonatal death). Logistic regression analysis was performed to evaluate parameters independently associated with the primary outcome. Logistic regression was reported as odds ratio (OR) with 95% confidence interval (CI). Results Mean gestational age at diagnosis was 30.6+/-9.5 weeks, with 8.0% of women being diagnosed in the first, 22.2% in the second and 69.8% in the third trimester of pregnancy. There were six miscarriage (2.3%), six intrauterine device (IUD) (2.3) and 5 (2.0%) neonatal deaths, with an overall rate of perinatal death of 4.2% (11/265), thus resulting into 17 cases experiencing and 226 not experiencing composite adverse fetal outcome. Neither stillbirths nor neonatal deaths had congenital anomalies found at antenatal or postnatal evaluation. Furthermore, none of the cases experiencing IUD had signs of impending demise at arterial or venous Doppler. Neonatal deaths were all considered as prematurity-related adverse events. Of the 250 live-born neonates, one (0.4%) was found positive at RT-PCR pharyngeal swabs performed after delivery. The mother was tested positive during the third trimester of pregnancy. The newborn was asymptomatic and had negative RT-PCR test after 14 days of life. At logistic regression analysis, gestational age at diagnosis (OR: 0.85, 95% CI 0.8-0.9 per week increase; pPeer reviewe

Risk Factors Associated with Adverse Fetal Outcomes in Pregnancies Affected by Coronavirus Disease 2019 (COVID-19): A Secondary Analysis of the WAPM study on COVID-19

To evaluate the strength of association between maternal and pregnancy characteristics and the risk of adverse perinatal outcomes in pregnancies with laboratory confirmed COVID-19. Secondary analysis of a multinational, cohort study on all consecutive pregnant women with laboratory-confirmed COVID-19 from February 1, 2020 to April 30, 2020 from 73 centers from 22 different countries. A confirmed case of COVID-19 was defined as a positive result on real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay of nasal and pharyngeal swab specimens. The primary outcome was a composite adverse fetal outcome, defined as the presence of either abortion (pregnancy loss before 22 weeks of gestations), stillbirth (intrauterine fetal death after 22 weeks of gestation), neonatal death (death of a live-born infant within the first 28 days of life), and perinatal death (either stillbirth or neonatal death). Logistic regression analysis was performed to evaluate parameters independently associated with the primary outcome. Logistic regression was reported as odds ratio (OR) with 95% confidence interval (CI). Mean gestational age at diagnosis was 30.6\ub19.5 weeks, with 8.0% of women being diagnosed in the first, 22.2% in the second and 69.8% in the third trimester of pregnancy. There were six miscarriage (2.3%), six intrauterine device (IUD) (2.3) and 5 (2.0%) neonatal deaths, with an overall rate of perinatal death of 4.2% (11/265), thus resulting into 17 cases experiencing and 226 not experiencing composite adverse fetal outcome. Neither stillbirths nor neonatal deaths had congenital anomalies found at antenatal or postnatal evaluation. Furthermore, none of the cases experiencing IUD had signs of impending demise at arterial or venous Doppler. Neonatal deaths were all considered as prematurity-related adverse events. Of the 250 live-born neonates, one (0.4%) was found positive at RT-PCR pharyngeal swabs performed after delivery. The mother was tested positive during the third trimester of pregnancy. The newborn was asymptomatic and had negative RT-PCR test after 14 days of life. At logistic regression analysis, gestational age at diagnosis (OR: 0.85, 95% CI 0.8-0.9 per week increase; p<0.001), birthweight (OR: 1.17, 95% CI 1.09-1.12.7 per 100 g decrease; p=0.012) and maternal ventilatory support, including either need for oxygen or CPAP (OR: 4.12, 95% CI 2.3-7.9; p=0.001) were independently associated with composite adverse fetal outcome. Early gestational age at infection, maternal ventilatory supports and low birthweight are the main determinants of adverse perinatal outcomes in fetuses with maternal COVID-19 infection. Conversely, the risk of vertical transmission seems negligible

A Simplified Approach for Stormwater Drainage Networks Sizing

In this work, a modification and a generalization of the “Italian-Storage method” (ISM), a renowned method for sizing rainstorm drainage systems, are proposed and applied. The approach adopts a steady non-linear rainfall-runoff transformation probabilistic model within a “variational” or “maximizing” procedure. In this model, the transformation of rainfall in “excess (or effective) rainfall” is accomplished by means of the Rational Method, while the travel time is neglected. The flow within each link of the system, induced by a rectangular shaped discharge hydrograph for any rainfall duration, is assumed to be unsteady but locally uniform (Kinematic modeling). Combining the hydrological and hydraulic sub-models, and considering different couples of rainfall heights-durations, consistent with the local IDF curve, a “critical duration” is evaluated. Once the critical duration has been obtained, a maximum of maxima instantaneous flow discharges is evaluated for such duration, and subsequently, with such a discharge each link of the storm water drainage system can be designed

Exact solution of the dam-break problem for constrictions and obstructions in constant width rectangular channels

In hydraulic engineering, it is common to find geometric transitions where the channel is not prismatic. Among the other geometric transitions, the constrictions and the obstructions are channel reaches where a cross-section contraction is followed by an expansion. These non-prismatic reaches are important because they induce rapid variations of the flow conditions. In the literature, the characteristics of the geometric transitions are well studied for the case of steady state flow, while less attention has been dedicated to the unsteady flow conditions. The present paper focuses on the exact solution of the dam-break problem in horizontal frictionless channels where constrictions and obstructions are present. In order to find this solution, the geometric transition is assumed to be short with respect to the channel length, and a stationary solution of the Shallow Water Equations is used to describe the flow through the non-prismatic reach. The mathematical analysis, carried out with the elementary theory of the non-linear hyperbolic systems of partial differential equations, shows that the dam-break solution always exists and it is unique for given initial conditions and geometric characteristics of the problem. The one-dimensional mathematical model proves to be successful in capturing the main characteristics of the flow immediately outside of the geometric transition when compared with a two-dimensional numerical model. The exact solution is then used to reproduce a set of experimental dam-break results, showing that the one-dimensional mathematical theory agrees with the laboratory data when the flow conditions through the constriction are smooth. The exact solutions presented here allow to construct a class of benchmarks for the one-dimensional numerical models that simulate the flow propagation in channels with internal boundary condition

Exact Solution of the Dam-Break Problem for Constrictions and Obstructions in Constant Width Rectangular Channels

In hydraulic engineering, it is common to find geometric transitions where a channel is not prismatic. Among these geometric transitions, constrictions and obstructions are channel reaches in which a cross-section contraction is followed by an expansion. These nonprismatic reaches are significant because they induce rapid variations of the flow conditions. In the literature, the characteristics of the geometric transitions have been well studied for the case of the steady-state flow, but less attention has been dedicated to the unsteady flow conditions. The present paper focuses on the exact solution of the dam-break problem in horizontal frictionless channels where constrictions and obstructions are present. In order to find this solution, the geometric transition is assumed to be short with respect to the channel length, and a stationary solution of the shallow water equations is used to describe the flow through the nonprismatic reach. The mathematical analysis, carried out with the elementary theory of the nonlinear hyperbolic systems of partial differential equations, shows that the dam-break solution always exists and that it is unique for the given initial conditions and geometric characteristics of the problem. The one-dimensional mathematical model proves to be successful in capturing the main characteristics of the flow immediately outside the geometric transition, in comparison with a two-dimensional numerical model. The exact solution is then used to reproduce a set of experimental dam-break results, showing that the one-dimensional mathematical theory agrees with the laboratory data when the flow conditions through the constriction are smooth. The exact solutions presented here allow the construction of a class of benchmarks for the one-dimensional numerical models that simulate the flow propagation in channels with internal boundary conditions

At-sea NATO operational experimentation with interoperable underwater assets using different robotic middlewares

Autonomous Underwater Vehicles (AUVs) are offering new capabilities for a wide range of military and civilian applications. The interoperability of heterogeneous AUVs with different skills is critical to accomplish such complex tasks. Indeed, the proliferation of AUVs with their own mission control interface and communications protocol makes it difficult to operate them within operational experimentations, which requires joint management and coordination. This problem was approached in the preparation of the ASW-ODC17 (Anti Submarine Warfare-Operational Deployment of Concepts) sea trial, which, among its objectives, aimed to demonstrate the interoperability of an external AUV (the Folaga WAVE) within the CMRE heterogeneous robotic network during a NATO operational exercise in ASW. The different hardware and software architectures were integrated by configuring an asset of the CMRE network (a gateway buoy) to act as a bridge between the two robotic systems. All the AUVs were successfully operated during the joint NATO exercise through the same mission control station, unconcerned by differences in acoustic modems and robotic middleware

One-dimensional Mathematical Modelling of Debris Flow Impact on Open-check Dams

The impact of debris flows on open-check dams is modeled as a Riemann problem in a rectangular cross-section channel with downstream dry state. Under the assumption that the energy is conserved through the structure, this special Riemann problem exhibits four different solution configurations. It is shown that the solution always exists, but there are ranges of the initial conditions and of the geometric characteristics for which the solution is not unique. Two different criteria for the disambiguation of the solution are proposed, and it is shown that these criteria are in agreement. The exact solutions presented can be used as internal boundary conditions in one-dimensional numerical models for the propagation of the debris-flow in river channels and narrow valleys, or as a numeric benchmark

SARS-CoV-2 Infection: A Clinical and Histopathological Study in Pregnancy

During pregnancy, SARS-CoV-2 infection is associated with several adverse outcomes, including an increased risk of pre-eclampsia, preterm delivery, hypertensive disorders, gestational diabetes, and fetal growth restriction related to the development of placenta vascular abnormalities. We analyzed human placenta from full-term, uncomplicated pregnancies with SARS-CoV-2 infection during the first, second, or third trimesters of gestation. We studied, by the immunohistochemistry technique, the expression of CD34 and podoplanin (PDPN) as markers of vasculogenesis to find any differences. As secondary outcomes, we correlated maternal symptoms with placental histological alterations, including fibrin deposits, lymphocyte infiltration in the villi, edema, and thrombi. Our results showed a PDPN expression around the villous stroma as a plexiform network around the villous nucleus of fetal vessels; significant down-regulation was observed in the villous stroma of women infected during the third trimester. CD34 showed no changes in expression levels. During SARS-CoV-2 infection, the most common maternal symptoms were fever, anosmia, ageusia and asthenia, and the majority were treated with paracetamol, corticosteroids and azithromycin. Patients that required multiple symptomatic treatments evidenced a large amount of fibrin deposition in the villi. Certainly, PDPN plays a key role in healthy placental vasculogenesis and thus in its proper physiology, and SARS-CoV-2 surely alters its normal expression. Further studies are necessary to understand what mechanisms are being altered to try to avoid possible complications for both the mother and fetus in terms of the contagions that will still occur

SARS-CoV-2 Infection: A Clinical and Histopathological Study in Pregnancy

During pregnancy, SARS-CoV-2 infection is associated with several adverse outcomes, including an increased risk of pre-eclampsia, preterm delivery, hypertensive disorders, gestational diabetes, and fetal growth restriction related to the development of placenta vascular abnormalities. We analyzed human placenta from full-term, uncomplicated pregnancies with SARS-CoV-2 infection during the first, second, or third trimesters of gestation. We studied, by the immunohistochemistry technique, the expression of CD34 and podoplanin (PDPN) as markers of vasculogenesis to find any differences. As secondary outcomes, we correlated maternal symptoms with placental histological alterations, including fibrin deposits, lymphocyte infiltration in the villi, edema, and thrombi. Our results showed a PDPN expression around the villous stroma as a plexiform network around the villous nucleus of fetal vessels; significant down-regulation was observed in the villous stroma of women infected during the third trimester. CD34 showed no changes in expression levels. During SARS-CoV-2 infection, the most common maternal symptoms were fever, anosmia, ageusia and asthenia, and the majority were treated with paracetamol, corticosteroids and azithromycin. Patients that required multiple symptomatic treatments evidenced a large amount of fibrin deposition in the villi. Certainly, PDPN plays a key role in healthy placental vasculogenesis and thus in its proper physiology, and SARS-CoV-2 surely alters its normal expression. Further studies are necessary to understand what mechanisms are being altered to try to avoid possible complications for both the mother and fetus in terms of the contagions that will still occur