Abstract: A novel multi-attribute decision-making approach which combines gray relational grade and the technique for order preference by similarity to an ideal solution(TOPSIS) is presented to solve the multiple attribute decisionmaking problem in which an attribute is a Vague valueFirst,it was necessary to establish the criteria for score function of the ideal solution and the negative ideal solution,this was determined based on the characteristics of Vague setsThen the gray relational grades of the ideal solution and the negative ideal solution in every alternative were calculatedNext,the relative closeness of every alternative was calculated based on TOPSIS and alternatives were ranked according to their values of relative closenessFinally,a numerical example was given to prove the approach to be more efficient and advantageous

Abstract: A new anthropomorphic robot with a five-finger dexterous hand-named HIT/DLR Hand Ⅱ-was developed to make hand appearance and structural functions more anthropomorphic.The hand is composed of an independent palm and five identical modular fingers,and each finger has three degrees of freedom(DOF) and four joints.To meet the mechatronic idea,all actuators,drivers,and electronics were integrated in the fingers and the palm.By using a steel coupling mechanism,the distal phalanx transmission ratio was kept exactly 1:1 over the whole movement range.The packing mechanism which was implemented in the fingers and palm not only reduces the size of whole hand but also makes it more anthropomorphic.The finger size is about one third of the former finger in this innovative design.In additional,the newly designed force/torque and position sensors are well integrated with the hand.It was verified by experiments that the dexterous hand not only met design goals,but also exhibits great grasping capacity.

Abstract: In recent years,proof of the environmental adaptability of warship designs has been highly regarded by some maritime powers and so large-scale model tests in real ocean environments were adopted for research.The research on environmental adaptability of ships in China is in its initial stages.The characteristics of offshore waves were analyzed by large-scale model tests in a real oceanic environment,and a method for predicting the nonlinear motion of ships using the harmonic probing method,which itself is based on the nonlinear auto regressive moving average exogenous inputs(NARMAX) model was also put forward.By comparing the results of this test with those done in tanks,it was shown that this method is feasible,and it provides a new and effective means for researching the environmental adaptability of ships.

Abstract: This paper describes a method that can be used to extrapolate the static electric field of ships.It is based on in-depth research on the mechanisms of generation and the properties of the static electric fields of ships.The method is based on a model simulating shipboard electrical fields.It can be used in both deep and shallow water,and can realize the extrapolation of the components of the static electric field and the underwater electric potential from somewhere to deeper seawater.Extrapolation of underwater electric potential was conducted in a laboratory using a physical scale model of a ship.The extrapolated results have the same distribution characteristics and order of magnitude as experimental results.The research results show that this method is feasible and of significance to the study of the distribution of electric fields of actual ships.

Abstract: The safety factor for a rock slope experiencing seismic activity is a function that changes with time.Assessments of the potential instability of a rock slope under seismic stress have been based on a time history of a rock slope's safety factor.This is a difficult engineering problem that remains unresolved.Based on the explicit finite element method,a new method of calculating the dynamic safety factor was proposed.To enhance reliability theory,a new concept,a dynamic stability evaluation index,more accurately called a dynamic safety factor of reliability,was proposed,and a method for calculating it was developed.The proposed dynamic safety factor of reliability of rock slope equals to the difference that the mean value of time history of dynamic safety factor of rock slope subtracts the product of standard error of time history of safety factor and risk level accepted by engineering.This compactly integrates stability evaluation of slope with an evaluation of acceptable levels of risk.The proposed method was used to calculate the safety factor for a rock slope,and the result was compared to that derived using the pseudo-static method.The comparison indicates that the proposed method is reliable,and can be used directly in engineering.

Abstract: A novel mathematic model of a dual three-phase permanent magnet synchronous motor(PMSM) was proposed to study electrical propulsion systems for ships.First the dual three-phase windings were transformed to equivalent dual two-phase windings with the same magnetomotive force and power,and then the dual two-phase windings were transformed to equivalent two-phase windings.After the above transformations,dual three-phase windings were equivalently transformed to two-phase orthogonal windings.With the mature mathematical model of the electrical machine in the two-phase rotary reference frame,the model of a dual three-phase PMSM was established.A mathematical model of 6-pole,2.2 kW dual three-phase PMSM in the dq coordinate system was built and simulated by Matlab/Simulink.Comparing the simulation results with corresponding test results,the maximum error was less than 5%.So this double winding transformation and modeling method is valid and correct.

Abstract: To understand the problem of snap tension in mooring lines in the taut-slack process,the factors affecting snap tension were studied by the experimental method.The investigation measured respectively;tension in the line;motion of the end point,including the amplitude and frequency of motion;characteristics of the marine line itself,including its length,stiffness and material.The results showed that,with the same pre-tension and excitation frequency,snap tension increases with increasing excitation amplitude;with the same excitation amplitude,the snap tension in the line increases with increasing excitation frequency.With the same excitation amplitude and frequency,the tension increases with increasing excitation amplitude,stiffness,and modulus.Snap tension decreases with increases in the length of the line.The results should provide a reference for theoretical analysis and engineering design.

Abstract: To better locate targets when the target's transmitting power changes,characteristics of wireless channel attenuation were analyzed.Extraction of features of signal strength differences unrelated with the target's transmitting power was also examined.A novel target localization method was proposed for wireless sensor networks(WSN) combining information exchange and processing,and based on least squares support vector regression(LSSVR) modeling of signal strength differences.With this method,mean received signal strength differences between different sensors were used to compose the initial feature vector.Then LSSVR models were obtained by LSSVR modeling;they represented mappings of relationships between a feature vector and a target's coordinates.Moreover,targets were located by inputting the feature vector composed of the measured signal strength differences among sensors into LSSVR models.The target localization experiment was performed using a WSN experimental platform using Texas Instruments CC2430 chipsets.It was proven that the root mean square error of the target localization-LSSVR Modeling Received Signal Strength Difference(TL-LMRSSD) method's maximum likelihood estimation(MLE) error reduced from 29% to 37%.Furthermore,the processing time for the TL-LMSD method was about 0.4s when LSSVR modeling was needed and about 0.04s when LSSVR modeling was not needed.This showed that the TL-LMSD method improved target localization accuracy by significantly reducing the influence of signal strength variations on target localization results.In addition,it showed good real-time performance.

Abstract: A meshing force model for misaligned gear couplings was derived,and a dynamic equation of the rotor system was established based on finite element analysis,while considering the influence of misaligned gear couplingsInfluence rules for meshing force on a rotor-gear coupling system were studied using simulations based on the numerical integral methodTheoretical analysis and simulation results showed: meshing force on gear couplings is related to structural parameters of the coupling,transfer torque,static misalignment,dynamic vibration displacement,etc;stiffness of the coupling,which is not a constant,relates to dynamic vibration displacement and depends on static misalignmentDynamic behavior of rotor-gear coupling systems reveals that 1X-rotational speed is the main response of system when there is no misalignment,while 2X,3X,4X-rotational speeds appear with some misalignments;moreover,when misalignment increases,the amplitudes of all frequencies become larger,and the vibrations of the system get more complexThese research results can provide important criteria for trouble shooting rotor systems connected by gear couplings

Abstract: Based on pressure sinkage laws and shear stress-displacement relationships in terramechanics,a mathematical model was developed to describe the motion performance of a drum type wheel.This should improve design,motion control,and vehicle simulation for the lunar rover.After establishing quantitative relationships between motion performance,soil properties and wheel dimensions,the drum wheel was divided into many slim cylindrical wheels.When analyzing radial and tangential stress distributions under the wheel-soil interface,it was found that maximum radial stress occurs in front of bottom-dead-centre and shifts forward when increasing slip is taken into account.On the basis of parameter measurements of loose sandy soil,the relationship between shear modulus and contact pressure was introduced.For theoretical analysis,the value of shear modulus which corresponds to load exerted on the experiment wheel was obtained by defining the area of drum wheel-soil contact.Experimental results from a single-wheel testbed operated in loose sandy soil shows that this model for predicting drum wheel performance is reliable.

Abstract: Seawater is a kind of conducting mediaAs a result steel watercraft emit electrical currents and these propagate through seawater and thus form an electrical fieldDetecting the electrical field of watercraft can be used to either locate underwater objects or for a long-distance maritime early-warning systemBy using the Maxwell equation under continuous boundary conditions of field potential and a normal component of current density,the authors made a quantitative analysis and computation of the changes in the electrical field generated by the constant static electric field in the vicinity of underwater objects such as underwater weaponry,electrical field measuring devices,etcTheoretical analysis and computations indicated that the influence of these changes is related to the distance between the watercraft and the measuring device,the measuring device's material,the seawater's resistivity ratio,and the size of the measuring deviceThe closer to the electrical field and the larger the device is,the greater the influenceExperiments in a nonmagnetic seawater tank validated the analysis and computations

Abstract: A problem in adaptive tracking control was considered for a class of highly nonlinear multi-input multi-output(MIMO) systems with both unknown system nonlinearities and unknown virtual control gain nonlinearities.By employing a radial basis function(RBF) neural network(NN) to approximate uncertain functions,and a nonlinear damping item to compensate for both external disturbances and modeling errors,a robust adaptive neural network control algorithm was developed based on dynamic surface control(DSC) and the Nussbaum gain approach.The proposed algorithm not only both solves problems of unknown control direction and possible controller singularity,but also solves the problem of "explosion of complexity" in the conventional backstepping method,reducing the computational load of the algorithm and making it convenient to implement in applications.In addition,the algorithm has good robustness,guaranteeing stability in a closed-loop system.Simulation results validated its effectiveness and performance.

Abstract: This paper presents the ESPRIT algorithm based on a high-order cumulant for direction of arrival(DOA) estimation using a single vector hydrophone that overcomes limitations of the autocorrelation algorithm.This method forms a temporal invariance via two time-delayed data sets collected from one vector hydrophone and constructs two sub-arrays with the same array shape.The ESPRIT algorithm based on a high-order cumulant was formulated by applying the orthogonality of high-resolution signal subspace and noise subspace and signal subspace rotation invariance to the cumulant domain.Simulation results show that the influence of white Gaussian noise is fully suppressed with the aid of the high-order cumulant and the method can provide high-precision,high-resolution asymptotically unbiased bearing estimates at an SNR of 6dB in Gaussian colored noise.

Abstract: The authors analyzed the influence of traffic composition on the behavior of traffic clearing intersections and queuing at lights on urban mixed use transport arteries.The influence of vehicle flow rates and other factors influencing the time required for vehicles to clear an intersection were determined.A fuzzy control model for signals controlling mixed traffic was established according to traffic characteristics.The time for green lights was prolonged for every cycle and changes to the regular phases were calculated by a fuzzy control algorithm according to the type of the lead vehicle,mix of vehicles present,characteristics of the main and secondary traffic routes and queue lengths.A simulation was run using the software VISSIM.A comparison with conventional methods showed that the optimized method reduced vehicle delays by an average of 3.6s,proving the feasibility and validity of this scheme.

Abstract: Based on grey characteristics of ship movements,this paper puts forward a method for modeling ship pitching using an improved GM(1,1) model.The improved GM(1,1) model assumes the sequence of movements is analogous to the non-uniform exponential law,breaking the restricted zone of the traditional GM(1,1) model with an approximate exponential law.First,the differential equation of the improved GM(1,1) model and the accurate discrete model were given and the initial point's effect on the model was discussed,establishing the optimized grey model.The model can improve precision of simulations.It offers a novel method for the prediction of ship pitching.Test results imply that the method is better than the standard GM(1,1) model.

Abstract: Effective prediction of potential construction quality failures for marine drilling platforms can result in improved construction quality and construction techniquesBased on descriptions of equipment and detailed requirements of quality inspection,a general regression neural network(GRNN) was used to provide predictionsTaking a particular jack up rig as an example,construction errors were predicted with 15 years' quality inspection dataIn order to show the effectiveness of this method for construction quality prediction,a comparison was made with predictions by a back-propagation neural network(BPNN)The result shows that GRNN is a useful prediction method which is more precise than BPNNOn the basis of the predictions,countermeasures were put forward to increase construction quality

Abstract: Maneuverability is one of the most important submarine craft performance factorsIn order to predict maneuverability,it is necessary to derive the craft's hydrodynamic qualities in advanceNumerical simulations using the planar motion mechanism(PMM) along with computational fluid dynamics(CFD) and moving mesh techniques were used to calculate the hydrodynamic derivatives of an ellipsoidThe acceleration coefficient was then compared with the theoretical valueThe flow field solution was based on Reynolds averaged Navier-Stokes(RANS) equations and the renormalization group(RNG) k-epsilon turbulence modelThe moving mesh was disposed of by the approach proposed by Hrvoje Jasak and Zeljko Tukovic,and the velocity and pressure decoupled by the PIMPLEmethodThe control equations for the flow and moving mesh were solved by the finite volume method and finite element method respectivelyEach cell was decomposed by cell-and-face splitComparing partial results from this method with theoretical results gives confidence that this approach will be useful to some degree for calculating hydrodynamic derivatives of objects with more complex geometry

Abstract: Material properties of composite panels and woodwork are greatly influenced by surface or inner defects.It is necessary to use nondestructive testing methods during the detection process.Artificial defects were made on surfaces and inside panels to simulate real defects.The electronic shearography speckle pattern interferometry method was used for nondestructive testing of pine wood samples.Different shearing values were evaluated during the process.When detecting surface defects,the pixel calibration method was used to get defect information for defects of 6mm,5mm,and 3mm diameters.Also the thermal loading method and the phase shifting technique were adopted to provide a detection process for inner,invisible defects.The defects which were close to the surface could be quickly and easily quantitatively detected.The whole detection set-up was easy and ran in real time.The results agreed well with actual defects.Therefore the proposed method is feasible.

Abstract: After droplets collide with a wall,they either break up,rebound,or adhesion occurs.The result depends on droplet size,incident velocity and angle,wall roughness,temperature,and so on.To study this problem,after considering the above factors,a droplet-wall collision model was constructed.Combined with the Euler-Lagrange two-phase model,the mechanics of collisions between single droplets,multiple droplets and walls were simulated.The computational results were as expected and in good agreement with experimental results,which shows the accuracy and reasonableness of the model used.

Abstract: A dynamic neural fuzzy model(DNFM) based adaptive control algorithm for ship course control was developed to overcome uncertainties arising from changes of model parameters.The DNFM identified the inverse dynamics of the Norrbin nonlinear auto regressive exogenous-inputs(NARX) ship model sufficiently,while the structure and parameters themselves were adjusted simultaneously.Well-trained DNFM was then connected with a proportional-plus-derivative(PD) controller in parallel to construct an adaptive controller for course control.The weights of the DNFM were further adjusted by an adaptive law whose independent variable was the output of the PD controller.Simulation results for course control of a standard 5446 twenty-foot equivalent unit(TEU) container vessel validated the effectiveness of the proposed algorithm.

Abstract: To study fracture performance and characteristics of concrete experiencing freeze-thaw cycles,applying the GBJ82-85 test method for frost resistance of concrete,freeze-thaw experiments were done with 72 concrete blocks which were classified into 24 groups.Four-point bending tests were used to examine the effects of water-cement ratio and air-entraining agents on fracture toughness,fracture energy and the dynamic elastic modulus of concrete subjected to 300 rapid freeze-thaw cycles.The microstructures of the concrete were also analyzed.The results showed that with increases in the number of freeze-thaw cycles,the fracture toughness of concrete,the loss of fracture energy,as well as the relative loss of dynamic elastic modulus showed a downward trend.The greater the water-cement ratio,the more severe the damage to the concrete as the number of freeze-thaw cycles increased.Air-entraining agents can significantly reduce the damage to concrete structures due to freeze-thaw cycles.The loss of fracture energy and the relative loss of dynamic elastic modulus keep a good linear relationship.

Abstract: Information entropy methods and principal component analysis(PCA) were introduced to the Hilbert-Huang transform(HHT) method to improve performance.To resolve the disadvantages of stopping criteria in the traditional empirical mode decomposition algorithm,an algorithm using Hilbert time-frequency spectrum entropy(TFSE) was proposed.Based on this,a new stopping criterion for sifting and decomposing was presented,and the algorithm for empirical mode decomposition(EMD) was improved as well.The improved algorithm for EMD gets more accurate results and to a certain extent overcomes the problems of false mode and modal mixtures in a HHT.Simulation results showed the effectiveness of this improved method using stopping criteria based TFSE and PCA.

Abstract: Gait recognition makes use of human walking patterns for biometric recognition and is a novel topic in the field.Effective segmentation using a simple method to extract silhouettes of walking figures from the background was the first step of our method;this played a key role in gait recognition.Then,morphology was used and a standardized and centralized image was obtained by geometric transformation.Afterwards gait energy image(GEI) was used as a feature extraction method——describing gait characteristics obtained using periodic sequence images according to their cyclical divisions.Following this,feature dimensionality was reduced through principal component analysis(PCA),two-dimensional principal component analysis(2DPCA),complete two-dimensional principal component analysis(C2DPCA) and weighted complete two-dimensional principal component analysis(WC2DPCA) respectively.The nearest neighbor classifier was then used to distinguish different human gaits.By balancing calculation and recognition rates,experimental results demonstrated that 2DPCA based on GEI has encouraging recognition performance with a recognition rate of about 95.43%.

Abstract: Most existing particle swarm-based feature gene selection approaches have a common problem,easily sinking into a local optimum.To solve this problem,a novel feature gene selection approach combining improved discrete particle swarm optimization and support vector machine(IDPSO-SVM) was proposed.The process began with extraction of genes with closely related classifications.Then particle swarm optimization(PSO) was used to search feature gene subsets in those extracted genes.The support vector machine(SVM) was then used as an evaluator to estimate performance of the selected feature gene subsets.The optimum feature gene subset was eventually acquired after massive iterations.It was noteworthy that the proposed algorithm uses a novel mechanism which may effectively avoid local optimums so that new optimum solutions are constantly found.Classification accuracy of the proposed algorithm on colon tumor dataset and prostate cancer dataset was respectively 96.8% and 99.0%,significantly higher than previous methods.This showed the proposed algorithm is effective and feasible.

Abstract: The mercury intrusion method and the scanning electron microscopic(SEM) method were used to study the influence of electrochemical chloride extraction treatment on the distribution and microstructures of ions in concreteSamples were selected from the zone near steel reinforcement and the outer surfaces of concrete specimens with different water to cement ratios after electrochemical chloride extraction(ECE) treatmentChloride ion,potassium ion and sodium ion content,pore structure and microstructure were tested on these samplesThe results show that after the ECE treatment ion content near steel for chloride ions,potassium ions and sodium ions,are respectively 1/2,5~10 times and 8~18 times their concentrations in the outer surfaceMeanwhile,there were some discontinuous granular hydration products and a little decomposed hydration calcium silicate hydrate(CSH) gelsHowever,a great deal of potassium ions and sodium ions accumulated near the steel where there was much less concentration of chloride ions than in the outer surface of the concreteAfter the ECE treatment,the concrete near the steel presented a higher porosity with more coarse pores and a weak microstructureOn the contrary,the outer surface concrete showed a compact microstructure with smaller pores and an intact hydration product network

Abstract: To satisfy training demands for walking patients with impaired cranial nerves,a lower limb gait rehabilitation robot with a 4-DOF gait mechanism was designed and its kinematics was deduced based on the closed-loop vector method.Furthermore,by analyzing the characteristics of natural human gait,a gait planning method was proposed to generate various gaits for the robot that satisfy the requirements of training,using adjustable parameters such as gait stride,gait cycle,and the ratio of the support period or swaying period to the gait cycle.Finally,using a simulation environment in Matlab\Simulink\SiMMechanics,correction of kinematics was demonstrated,validating the proposed gait planning method.The simulation results can also be used for optimizing design of the mechanical parameters while supplying necessary data and building a theoretical foundation for subsequent research on the whole control system involving robot and patient.

Abstract: Enhancing the stability of magnesium oxychloride cement (MOC) will allow greater production and application of magnesium oxychloride cement.The formation,solution and phase change of hydration products in an MgO-MgCl2-H2O system were analyzed by the thermodynamics method.Experiments were done testing resistance of the concrete to immersion in water and examining the phase change rules for the curing of magnesium oxychloride cement at various MgO/MgCl2 molar ratios.The results showed that pH values of solutions in which MOC concrete is immersed clearly influenced phase stability of hydration products.A higher pH value led to lower solubility and better phase stability of hydration products.When the solution's pH value was higher than 10.37,the precipitation of a significant volume of Mg(OH)2 crystals decreased phase stability of hydration products.With increased MgO/MgCl2 molar ratio (lower than 6),increased MgO in the hydration products enhanced the alkalinity of the solution and phase stability was improved.However,when the MgO/MgCl2 molar ratio was higher than 6 excessive MgO existed in the hydration products.Such concrete may be damaged by the excessive crystallization stress of a great deal of Mg(OH)2 formation.

Abstract: Owing to the existence of planing forces and cavitation,modeling and control problems for supercavitating vehicles are very complicated.A model predigestion process would produce some modeling errors,while using the robust pole assignment method to control the supercavitating vehicle can overcome this defect efficiently.The authors analysed the hydrodynamic characteristics of supercavitating vehicles,focusing on analysis and integration of the dynamics of planing forces.A dynamic model of a supercavitating vehicle was then built in the longitudinal plane.Finally a controller was designed using the robust pole assignment method.Simulation results showed that the control system is both robust and stable.Moreover,when the control efficiency of various control variables was compared,it became clear that a cavitator allows better control than fins.

Abstract: In order to satisfy the need for remote monitoring of ocean-going ships by more effective methods,back propagation(BP) neural networks were applied to improve existing monitoring systems by anticipating failure and so outputting warning signals instead of failure signals.During this process,the alarm apparatus on board could be actuated while relevant failure identification codes are sent to company management ashore.Subsequently,the best method to solve the problem could be worked out between the ship's crew and engineers ashore.To analyze the application of BP neural networks to remote surveillance,changing trends in the exhaust temperature of a six cylinder main diesel engine were simulated.Making use of the learning ability of BP neural networks,a warning model was proposed for when continually rising exhaust temperature potentially leads to engine failure.Five more non-warning models were established for other conditions.The errors between the samples and the results simulated by BP neural networks were smaller than 5%,consequently BP neural networks can judge the trend of failure and improve monitoring systems by implementing failure prediction functions.