The Automatic Identification System (AIS) tracks vessel movement by means of electronic exchange of navigation data between vessels, with onboard transceiver, terrestrial and/or satellite base stations. The gathered data contains a wealth of information useful for maritime safety, security and efficiency. This paper surveys AIS data sources and relevant aspects of navigation in which such data is or could be exploited for safety of seafaring, namely traffic anomaly detection, route estimation, collision prediction and path planning.• Real time anomaly detection can identify potential se-1 Operating costs usually include crew, stores and lubes, maintenance and repair, insurance costs and overhead costs and are often distinguished from voyage costs such as fuel and bunkering cost.2 It should be mentioned that there are also other types of data (such as radar, video etc.) that can be used for these applications, but their corresponding algorithms and mechanisms are quite different from that of AIS based and thus are out of the scope of this paper.
using a delicate draw-spinning process such as that of spider silk is challenging. Crosslinking is one of the indispensable structural characteristics contributing to the strength and toughness of fibers. This is because the molecular chains are locked in the crosslinking network, [12] however, making it nonspinnable.Efforts have been made to spin a fiber from a linear polymer or a soluble precursor followed by an additional crosslinking step. [6,7,13] Moreover, novel spinning methods, such as wet spinning, [14,15] dry spinning, [16,17] micro fluidic spinning, [18][19][20] electro-spinning, [21,22] templating, [23] and dynamic crosslinked spinning, [24] have been developed. However, this increases the complexity of the spinning process, and controlling the hierarchical structure of the fiber becomes difficult. Consequently, so far the combination of strength and toughness of the artificial fibers still have a big gap to reach those of the spider dragline silk.The β-sheets in spidroin serve as crosslinking points, and the crosslinking network is localized inside this nanometersized globular protein. Therefore, spidroin is soluble and can be directly draw-spun to produce a hierarchical fiber via selfassembly (Figure 1a). Inspired by the spidroin structure and the spinning process, herein we prepared a soluble nanogel with an internal crosslinked network, which can be drawn-spun to form hierarchical fibers with nanoassemblies (Figure 1b). Theoretical modeling provided understanding of the fiber's spinning capacity as a function of the nanogel size. The introduction of Spider dragline silk is draw-spun from soluble, β-sheet-crosslinked spidroin in aqueous solution. This spider silk has an excellent combination of strength and toughness, which originates from the hierarchical structure containing β-sheet crosslinking points, spiral nanoassemblies, a rigid sheath, and a soft core. Inspired by the spidroin structure and spider spinning process, a soluble and crosslinked nanogel is prepared and crosslinked fibers are drew spun with spider-silk-like hierarchical structures containing cross-links, aligned nanoassemblies, and sheath-core structures. Introducing nucleation seeds in the nanogel solution, and applying prestretch and a spiral architecture in the nanogel fiber, further tunes the alignment and assembly of the polymer chains, and enhances the breaking strength (1.27 GPa) and toughness (383 MJ m −3 ) to approach those of the best dragline silk. Theoretical modeling provides understanding for the dependence of the fiber's spinning capacity on the nanogel size. This work provides a new strategy for the direct spinning of tough fiber materials.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adma.202201843.
Abstract. In recent years, maritime safety and efficiency become very important across the world. Automatic Identification System (AIS) tracks vessel movement by onboard transceiver and terrestrial and/or satellite base stations. The data collected by AIS contain broadcast kinematic information and static information. Both of them are useful for maritime anomaly detection and vessel route prediction which are key techniques in maritime intelligence. This paper is devoted to construct a standard AIS database for maritime trajectory learning, prediction and data mining. A path prediction method based on Extreme Learning Machine (ELM) is tested on this AIS database and the testing results show this database can be used as a standardized training resource for different trajectory prediction algorithms and other AIS data based mining applications.
Bioelectrical impedance phase angle has been recommended as a tool to assess nutrition state, but there are no measuring devices have been specially designed for hospital residents. In this study, a system was established for the measurement of bioelectrical impedance phase angle. The electrical composition, calculation method and measuring method of this system are presented in this paper. Experiments showed excellent performance of this system in measuring impedance made of resistors and capacitors. The designed system was also used to measure the bioelectrical impedance phase angle of both healthy subjects and patients with malnutrition, and the results demonstrated that the phase angle of patients with malnutrition is lower than that of healthy subjects (P < 0.01 for male and P < 0.05 for female). These results suggest that phase angle has the potential to be a useful tool for the quantitative assessment of nutritional status.
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