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AbstractThe rise in natural disasters and climate-induced events, such as wildfires, hurricanes, and flooding, has significantly affected urban life. These events can disrupt daily activity and flows of individuals and goods on road and transit networks. To enhance urban resilience against disasters, it’s crucial to study and understand road network vulnerability, utilizing data-driven insights to inform planning and preparedness efforts. The aim of this paper is to develop a data-driven exploratory approach to assess vulnerability in road networks in response to a disruption. To accomplish this, we compare the centrality of road segments before, during, and after disaster, considering the network topological structure and movement activity as it is observed through large tracking data of cellphone traces on the network. The novelty of our approach lies in inferring the impact from movement data, instead of manually removing links from the network. The results obtained from this study suggest that incorporating movement data into the assessment of network functionality provides a more realistic estimation of the road network vulnerability in response to a disruption, compared to solely using network topology. [ABSTRACT FROM AUTHOR]

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]

Abstract: Homokinetic motion transmission between two shafts with axes intersecting at right angles is a recurrent problem; the term quasi-homokinetic indicates that a constant 1:1 velocity ratio between the input and output is the design target, even though this cannot be fully met with a four-bar linkage. A four-bar spherical linkage is optimally designed, which performs “homokinetically” with minimum error through a 120° rotation of its input link, large enough for one specific robotics application. This is done via: (i) minimizing the root-mean-square value of the design error, i.e., the residual of the synthesis equations at the prescribed set of input values; and (ii) directly minimizing the structural error, i.e., the deviation of the generated output angles from the prescribed set. The novelty of the first method lies in that it provides all stationary points, and hence, the global minimum; finding a continuum of minima leaves ample room for maximizing the transmission quality. Further, the effect of data-set cardinality on the structural error is analyzed, which is then minimized directly. A new mechanism is thus obtained with a minimum structural error, but with a slightly compromised transmission quality. [Copyright &y& Elsevier]