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Cellular approaches facilitate the flexible design of materials with desirable properties that may be manufactured from single polymers, metals, and, recently, fiber-reinforced composites. This paper describes cellular materials with metal and carbon fiber-reinforced plastic (CFRP) struts. Composite lattice tubular structures were automatically braided, and the effects of axial CFRP yarns on the compressive behaviors of braided lattices were studied. Metal wire-reinforced plastic and metal rods served as axial yarns when preparing hybrid triaxially braided metal-CFRP lattices. The effects of the axial yarns in polyurethane (PU) foam-filled samples were also assessed. Ten braided structures were manufactured, and their compressive behavior and energy absorption were evaluated by axial compression tests. Finite element (FE) simulations were used to investigate deformation, buckling, and damage. Addition of axial CFRP yarns improved the compressive properties; the specific absorbed energy (SAE) increased by 16%. Hybridization further enhanced the SAE by 62%. [ABSTRACT FROM AUTHOR]

A series of structurally diverse spiro 1,3-oxazines were conveniently prepared from three-component reaction of conjugated imines, dialkyl acetylenedicarboxylates (DAAD), and N,N'-disubstituted parabanic acids in dry dichloromethane without catalyst. Initially, various conjugated imines were synthesized from reaction of aniline derivatives with cinnamaldehyde. Subsequently, reaction of conjugated imines with DAAD and N,N'-substituted parabanic acids led to mixture of the corresponding spirocyclic 1,3-oxazines in high yields. The obtained diastereoisomers of the spirocyclic 1,3-oxazines were isolated and characterized by FT-IR, 1H, 13C NMR spectral data, elemental analyses and mass spectrometry. [ABSTRACT FROM AUTHOR]

Maritime traffic prediction is a crucial task for increasing the efficiency of port operations and safety, especially in congested regions. A huge amount of automatic identification system (AIS) data is constantly transmitting from vessels to receivers that contain information about vessels' movements and characteristics. These historical AIS data can be utilized in movement analyses of vessels. This paper proposes a novel point-based model for location and traffic prediction using vessels' trajectories adapted from AIS measures. The location prediction procedure is setup based on similarity analysis of historical AIS data. The model is applied to a real dataset of hundreds of vessels' trajectories in the Strait of Georgia, USA. The correlation results of 0.9976, 0.9887, and 0.9794 for the next 10, 20, and 30 minutes, respectively, imply sufficient correspondence between predicted and actual coordinates. The traffic prediction procedure considers the probability of the appearance of new vessels inside an area of interest (AoI) at different time intervals. The Sorenson similarity index (SSI) is used to measure the accuracy of the traffic prediction model. The SSIs for time intervals of 10, 20, and 30 minutes are 70%, 66%, and 59%, respectively, which show the robustness of the model to predict hot spots inside the AoI. [ABSTRACT FROM AUTHOR]

For maritime safety and security, vessels should be able to predict the trajectories of nearby vessels to avoid collision. This research proposes three novel models based on similarity search of trajectories that predict vessels' trajectories in the short and long term. The first and second prediction models are, respectively, point-based and trajectory-based models that consider constant distances between target and sample trajectories. The third prediction model is a trajectory-based model that exploits a long short-term memory approach to measure the dynamic distance between target and sample trajectories. To evaluate the performance of the proposed models, they are applied to a real automatic identification system (AIS) vessel dataset in the Strait of Georgia, USA. The models' accuracies in terms of Haversine distance between the predicted and actual positions show relative prediction error reductions of 40·85% for the second model compared with the first model and 23% for the third model compared with the second model. [ABSTRACT FROM AUTHOR]