From electronic navigational chart data to sea-bottom models: Kriging approaches for the Bay of Pozzuoli

<p class="Abstract">Electronic Navigational Charts (ENCs), official databases created by a national hydrographic office and included in Electronic Chart Display and Information System (ECDIS), supply, among essential indications for safe navigation, data about sea-bottom morphology in terms of depth points and isolines. Those data are very useful to build bathymetric 3D models: applying interpolation methods, it is possible to produce a continuous representation of the seafloor for supporting studies concerning different aspects of a marine area, such as directions and intensity of currents, sensitivity of habitats and species, etc. Many interpolation methods are available in literature for bathymetric data modelling: among them kriging ones are extremely performing, but require deep analysis to define input parameters, i.e. semi-variogram models. This paper aims to analyze kriging approaches for depth data concerning the Bay of Pozzuoli. The attention is focused on the role of semi-variogram models for Ordinary and Universal kriging. Depth data included in two ENCs, namely IT400129 and IT400130, are processed using Geostatistical Analyst, an extension of ArcGIS 10.3.1 (ESRI). The results testify the relevance of the choice of the mathematical functions of the semi-variogram: Stable Model supplies, for this case study, the best performance in terms of depth accuracy for both Ordinary and Universal kriging.</p>

A route calculation for unmanned vessel

Рассматривается проблема определения маршрута движения безэкипажного судна с учетом жестких требований контроля положения и курса судна. Современные электронно-картографические навигационно-информационные системы в режиме управления траекторией определяют точку поворота для выхода на новый участок маршрута, что недостаточно для управления безэкипажным судном в автономном режиме. Для повышения точности предложено проводить расчет траектории движения безэкипажного судна в географических координатах c учетом движения судна по радиусу поворота между участками траектории без перевода в прямоугольную систему координат. Показано, что при движении в свободной акватории проблема может быть сведена к решению обратной геодезической задачи. Предложен универсальный алгоритм расчета траектории в виде сегментов дуг большого круга, позволяющий получить путевые точки маршрута с любой заданной точностью. В случае возникновения ограничений на движение между двумя участками по внутреннему радиусу необходимо рассчитать альтернативный маршрут обхода препятствия. Для данного случая предложен расчетный маневр, полученный на основе решения задачи Дубинса. Альтернативный маршрут формируется в виде последовательности криволинейных сегментов, соответствующих заданному радиусу поворота. Алгоритм расчета путевых точек позволяет получить траекторию обхода препятствия с любой степенью детализации. A route calculation problem for unmanned vessels is investigated according to the control position and course high requirements. Present day electronic chart display and information systems (ECDIS) operating on the track control regime provide wheel-of-point calculation to course changing. It is not enough to control unmanned ship on the route in the autonomous mode. To increase control precision a new route calculation routine is suggested. The routine provides route calculation in the geodesic coordinates without Cartesian reference system mapping. It is shown that in the empty water the routine can be reduced to an inverse survey computation. A universal route calculation algorithm providing great circle arc segmentation with any given accuracy is suggested. In the case of course changing restricted area, it is needed to calculate an alternate route for obstacle or collision avoidance. The algorithm of alternate route calculation based on Dubins problem solution is applied. The route is found as a sequence of great circle arcs according to the ship turn radius. The shown algorithm allows finding avoidance route waypoints with any given resolution.

Development of Fuel Calculation Applications Android Based for Ship Operations

This study aims to develop an android-based application to calculate the amount of fuel adjusted to the distance and speed of the ship based on the trajectory (way point). The calculation of distance in this application uses the concept of a spherical triangle which is used in voyage navigation. This development adopts the Waterfall model with the stages of Requirement Engineering, Design and implementation, Testing, Release and Maintenance. At the product review stage, it involves software experts (to provide criticism and suggestions for improvement), then testing is carried out by comparing the results of calculations using applications with manual calculations and ECDIS (electronic Chart Display Information System). The test results show that there is no significant difference between the results of calculations using the application with manual calculations and ECDIS. Thus, this application can be used to calculate the amount of fuel needed according to the distance traveled and the speed of the ship based on the selected trajectory.

Chemical and Physical Activation Using a Microwave to Increase the Ability of Activated Carbon to Adsorb Dye Waste

This study aims to develop an android-based application to calculate the amount of fuel adjusted to the distance and speed of the ship based on the trajectory (way point). The calculation of distance in this application uses the concept of a spherical triangle which is used in voyage navigation. This development adopts the Waterfall model with the stages of Requirement Engineering, Design and implementation, Testing, Release and Maintenance. At the product review stage, it involves software experts (to provide criticism and suggestions for improvement), then testing is carried out by comparing the results of calculations using applications with manual calculations and ECDIS (electronic Chart Display Information System). The test results show that there is no significant difference between the results of calculations using the application with manual calculations and ECDIS. Thus, this application can be used to calculate the amount of fuel needed according to the distance traveled and the speed of the ship based on the selected trajectory.

Multi-Criteria Selection of Surface Units for SAR Operations at Sea Supported by AIS Data

The authors discuss currently conducted research aimed at improving the planning and performance of search and rescue (SAR) operations at sea. The focus is on the selection of surface units in areas of high traffic density. A large number of ships in the area of distress can make the process of selection of best suited vessels longer. An analysis of features which may render a vessel unsuitable for the job, depending on the area and type of operation, has been conducted. Criteria of assessment and selection of ships have been described, preceded by an expert analysis. The selection process has been made using Multi-Criteria Decision Analysis (MCDA). The authors propose to apply officially available data from the Automatic Identification System (AIS)—a sensor for the ECDIS and other electronic chart systems—in the analysis of the availability of ships. Algorithms filtering available units have been built and applied in a simulation, using real AIS data, of one of the most common types of SAR operations. The method is proposed as an enhancement of decision support systems in maritime rescue services.

Solusi Akses ENC S-63 Pushidrosal Untuk Kapal Angkatan Laut, Pangkalan Dan Marinir

PLI (Peta Laut Indonesia) dan ENC (Electronic Nautical Chart) adalah produk utama Pushidrosal sebagai lembaga hidrogafi yang dipergunakan untuk keselamatan navigasi. Konvensi SOLAS (Safety of Life at Sea) mengatur bahwa peta navigasi laut yang legal adalah produk dari lembaga hidrografi yang menjadi perwakilan negara di IHO (International Hydrographic Organization). IMO (International Maritime Organization) telah mewajibkan program ECDIS (Electronic Chart Display Information System) mandatory terutama bagi kapal – kapal yang digunakan untuk pelayaran internasional. Hal tersebut mendorong semakin berkembangnya ENC (Electronic Nautical Chart) sebagai produk utama lembaga hidrografi. Pushidrosal mendistribusikan ENC dengan standar S-63. Standar ENC S-63 menjamin keamanan data melalui metode enkripsi. KAL (Kapal Angkatan Laut), Pangkalan Angkatan Laut dan Marinir memerlukan peta laut yang di-update secara periodik sebagai data referensi wilayahnya. Idealnya unit – unit tersebut mempunyai ECDIS agar dapat mengakses ENC S-63 sebagai produk yang update setiap bulan, namun terkendala oleh biaya yang mahal. Hambatan tersebut kini dapat diatasi dengan adanya software ECS (Electronic Charting System) OpenCPN yang dilengkapi dengan S-63 plugin. Dengan kemampuan tersebut, OpenCPN memberikan solusi bagi KAL, Pangkalan dan Marinir untuk dapat mengakses dan memanfaatkan produk ENC S-63, sehingga peta laut yang menjadi referensi adalah peta digital yang selalu dapat di-update secara periodik dengan mudah.

A Real-Time Collision Avoidance Framework of MASS Based on B-Spline and Optimal Decoupling Control

Real-time collision-avoidance navigation of autonomous ships is required by many application scenarios, such as carriage of goods by sea, search, and rescue. The collision avoidance algorithm is the core of autonomous navigation for Maritime autonomous surface ships (MASS). In order to realize real-time and free-collision under the condition of multi-ship encounter in an uncertain environment, a real-time collision avoidance framework is proposed using B-spline and optimal decoupling control. This framework takes advantage to handle the uncertain environment with limited sensing MASS which plans dynamically feasible, highly reliable, and safe feasible collision avoidance. First, owing to the collision risk assessment, a B-spline-based collision avoidance trajectory search (BCATS) algorithm is proposed to generate free-collision trajectories effectively. Second, a waypoint-based collision avoidance trajectory optimization is proposed with the path-speed decoupling control. Two benefits, a reduction of control cost and an improvement in the smoothness of the collision avoidance trajectory, are delivered. Finally, we conducted an experiment using the Electronic Chart System (ECS). The results reveal the robustness and real-time collision avoidance trajectory planned by the proposed collision avoidance system.

Machine Learning Algorithm Using Electronic Chart-Derived Data to Predict Delirium After Elderly Hip Fracture Surgeries: A Retrospective Case-Control Study

Background: Elderly patients undergoing hip fracture repair surgery are at increased risk of delirium due to aging, comorbidities, and frailty. But current methods for identifying the high risk of delirium among hospitalized patients have moderate accuracy and require extra questionnaires. Artificial intelligence makes it possible to establish machine learning models that predict incident delirium risk based on electronic health data.Methods: We conducted a retrospective case-control study on elderly patients (≥65 years of age) who received orthopedic repair with hip fracture under spinal or general anesthesia between June 1, 2018, and May 31, 2019. Anesthesia records and medical charts were reviewed to collect demographic, surgical, anesthetic features, and frailty index to explore potential risk factors for postoperative delirium. Delirium was assessed by trained nurses using the Confusion Assessment Method (CAM) every 12 h during the hospital stay. Four machine learning risk models were constructed to predict the incidence of postoperative delirium: random forest, eXtreme Gradient Boosting (XGBoosting), support vector machine (SVM), and multilayer perception (MLP). K-fold cross-validation was deployed to accomplish internal validation and performance evaluation.Results: About 245 patients were included and postoperative delirium affected 12.2% (30/245) of the patients. Multiple logistic regression revealed that dementia/history of stroke [OR 3.063, 95% CI (1.231, 7.624)], blood transfusion [OR 2.631, 95% CI (1.055, 6.559)], and preparation time [OR 1.476, 95% CI (1.170, 1.862)] were associated with postoperative delirium, achieving an area under receiver operating curve (AUC) of 0.779, 95% CI (0.703, 0.856).The accuracy of machine learning models for predicting the occurrence of postoperative delirium ranged from 83.67 to 87.75%. Machine learning methods detected 16 risk factors contributing to the development of delirium. Preparation time, frailty index uses of vasopressors during the surgery, dementia/history of stroke, duration of surgery, and anesthesia were the six most important risk factors of delirium.Conclusion: Electronic chart-derived machine learning models could generate hospital-specific delirium prediction models and calculate the contribution of risk factors to the occurrence of delirium. Further research is needed to evaluate the significance and applicability of electronic chart-derived machine learning models for the detection risk of delirium in elderly patients undergoing hip fracture repair surgeries.

Lidocaine for dinutuximab associated pain? A multicenter retrospective observational cohort study

Dinutuximab, an immune-mediated therapy used in the treatment of high-risk neuroblastoma targets the protein disialoganglioside (GD2) present on neuroblastoma cells, neurons, and peripheral nerve fibers. Off target effects could lead to severe nerve pain. Pain regimens including continuous infusion opioids are required during the first treatment course. Our institution utilizes a combination of intravenous (IV) lidocaine infusions and morphine for the treatment of dinutuximab-associated neuropathic pain. The primary outcome of this study was to compare morphine equivalents for cycle one of dinutuximab at an institution that uses IV lidocaine (primary) versus those that do not (comparison). Secondary outcomes included both dinutuximab infusion time and safety of IV lidocaine. A retrospective, multi-centered, electronic chart review was performed at three tertiary academic medical centers. Patients between 0-18 years of age during their first course of dinutuximab were included to evaluate the primary outcome of adjuvant morphine equivalents needed. Total morphine equivalents at the primary institution were 1.87 mg/kg vs 1.79 mg/kg at the comparison institutions (p=0.413). Dinutuximab infusion time was significantly lower at the primary institution: 610.5 minutes vs 676.23 minutes (p=0.046). Only one patient at the primary institution experienced nausea, vomiting and paresthesias. This study did not find a statistically significant difference in morphine equivalents between patients who received IV lidocaine and those who did not. However, we did find that use of IV lidocaine resulted in a statistically significant lower dinutuximab infusion time and that it is a safe adjuvant medication in the treatment of dinutuximab-associated neuropathic pain.