Past,present, and future of the satellite-based automatic identification system: areas of applications (2004–2016)

In 2016, the world shipping fleet grew by 3.5%. Even if the annual growth rate remains at its lowest since 2013, the global situation is still in overcapacity (UNCTAD 2016). Ninety percent of global trade, by volume, is done by sea. Monitoring this fleet helps with vessel navigation, informing to help avoid critical situations such as collisions, accidents leading to oil pollution, grounding, or ships in distress, but also because traffic management in congested areas is essential. For system wide management, in regions such as MPAs (marine protected areas), conservation is the key factor, and movements can be monitored and analyzed in order to determine illegal or suspicious activities, or in order to limit and/or divert traffic, to mitigate the risks to species subject to protection. It is among these efforts that the automatic identification system (AIS) can play a key role. Since 2004, this VHF transceiver-based reporting system, imposed by the International Maritime Organization (IMO), has shifted from a traditional vessel identification device to a tool used in a wide variety of applications. The most common uses are safety and security; these issues are quite visible in the media and may touch more people on a global scale (e.g., piracy, oil spills). Over the years, AIS has become, especially with the emergence of the satellite-based capture of the signal in 2011, a widely used tool for developing applications such as fisheries monitoring, marine conservation, air pollution forecasting and modeling, ballast water monitoring, invasive species transport, and many more. In this paper, we propose to review the peer-reviewed publications related to the uses and applications of the AIS.     

运用周期性边界条件预报螺旋桨的敞水性能

Mathematical models of propellers were created that investigate the influence of periodic boundary conditions on predictions of a propeller’s performance. Thrust and torque coefficients corresponding to different advance coefficients of DTMB 4119, 4382, and 4384 propellers were calculated. The pressure coefficient distribution of the DTMB 4119 propeller at different sections was also physically tested. Comparisons indicated good agreement between the results of experiments and the simulation. It showed that the periodic boundary condition can be used to rationally predict the open water performance of a propeller. By analyzing the three established modes for the computation, it was shown that using the spline curve method to divide the grids can meet the calculation’s demands for precision better than using the rake cutting method.     

FPSO与油轮串靠外输时的系泊时域分析

Problems experienced during Floating Production, Storage and Offloading (FPSO) tandem offloading operations were investigated. The aim of this research was to improve the reliability of such systems, and it needed a means to assess them. Time-domain simulation and analysis of offloading systems was performed using the multi-body mooring software ARIANE 7.0. Hydrodynamic interaction between the vessels was considered. The responses of the offloading system in different loading cases, different parameters of offloading hawsers and the effects of challenging environmental conditions were calculated. There was a focus on the problems of relative motion between the two bodies and its effects on the intensity of hawser forces. Minimum relative distance, maximum relative headings and maximum tension in the hawsers of offloading systems were obtained by time-domain analysis. The time-domain analysis was effective and comparative study can be used to optimize parameters of the system and extend operating limits.     

Construction of eukaryotic recombinant vector of renalase and its expression as a eukaryotic protein

Renalase is a secreted amine oxidase that metabolizes catecholamines. It has been proposed to modulate blood pressure and heart rate and its downregulation might result in hypertension. Despite its potential relevance for human health, the biochemical characterization of renalase is still scarce. The aim of this study is to synthesize the human renalase eukaryotic protein by genetic engineering. The human renalase gene was amplified by polymerase chian reaction (PCR). After digestion by BamH I and Xho I enzymes, the DNA fragments were cloned into the transfer vector, pFastBacHTb-Fc, to generate the pFastBacHTb-renalase expression vector. The ligation products were transformed into E. coli DH10Bac to obtain recombinant transposon rBacmid-renalase. The recombinant transposon was further transferred into insect high-V cells, and the recombinant human renalase eukaryotic protein was expressed successfully.     

Numeric-based XML labeling schema by generalized dynamic method

Most efficient indeces and query techniques over XML (extensible markup language) data are based on a certain labeling scheme, which can quickly determine ancestor-descendant and parent-child relationship between two nodes. The current basic labeling schemes such as containment scheme and prefix scheme cannot avoid relabeling when XML documents are updated. After analyzing the essence of existing dynamic XML labels such as compact dynamic binary string (CDBS) and vector encoding, this paper gives a common unifying framework for the numeric-based generalized dynamic label, which can be implemented into a variety of dynamic labels according to the different user-defined value comparison methods. This paper also proposes a novel dynamic labeling scheme called radical sign label. Extensive experiments show that the radical sign label performs well for the initialization, insertion and query operations, and especially for skewed insertion where the storage cost of the radical sign label is better than that of former methods.     

Nonlinear feedforward and feedback control design for autonomous underwater glider

Underwater gliders are highly efficient, buoyancy-driven, and winged autonomous underwater vehicles. Their dynamics are multivariable nonlinear systems with unstable internal dynamics and thus their motion control is a significant challenge. To improve the inherent efficiency and enhance the behavior of the underwater glider over a wide operating regime, a nonlinear feedforward and feedback controller was developed. The nonlinear feedforward control design is based on a new stable inversion technique which determines a causal and bounded solution for the unstable internal dynamics. The feedback control law was designed by a quadratic optimal control method. Simulation results show that the derived control system is able to deal with nonminimum phase system and successfully achieves the tracking of planned output trajectories from initial to final conditions. Furthermore, the control effort is very low, which means the glider with limited power storage has longer range and higher endurance.     

Numerical analysis of material properties in deformation of near hemispherical shells

In this paper, the effects of hardening exponent, yield strength and elastic modulus on the deformability of near hemispherical shells are investigated by means of finite element method and orthogonal experiment design. The largest eccentric angle during the deformation process and thickness reduction after the deformation are introduced to estimate the deformability quantitatively according to the deformation characteristics of near hemispherical shells. The results indicate that the hardening exponent is the most influential parameter, followed by elastic modulus and yield strength. The shell exhibits good deformability when the hardening exponent and elastic modulus are in the range of 0.1–0.125 and 70–108 GPa, respectively.     

Dynamic investigation on floating raft with elastic limiters

In this paper, we consider a floating raft isolation system with elastic limiters. The limiters might be “contact” or “no contact”, thus forming a unilateral system generating possible contacts. In order to avoid the large displacement of the floating raft under shock, limiters might be adopted but good limiters design requires the values of the gaps. Based on the contact dynamics, the multi-degree-freedom dynamic model of floating raft isolation system with elastic limiters is established. The artificial neural network has been developed to dingtinguish the contact state of elastic limiters at each step. The example analysis shows that the algorithm of neural network for contact can shorten the time of caclaution. From the example analysis, we get some interesting results that may be useful to the ship engineering.     

Upper limb musculo-skeletal model for biomechanical investigation of elbow flexion movement

A biomechanical musculo-skeletal model of upper limb is presented in this paper, which can provide accurate representations of muscles and joints, and capture important interactions between joints. The upper limb model is made up of seven segments: ribs, sternum, clavicle, scapular, humerus, radius and ulna, considered as a single rigid body respectively and includes 22 muscles. The individual muscle forces can be calculated by using an electromyography (EMG) assisted method, which is verified by comparing the simulation results with other researches of an elbow flexion motion. These comparisons show that the muscle forces and the estimated joint moment match well with previous literatures.