This paper presents a probabilistic failure analysis of leakage of the oil and gas in a subsea production system using fault tree analysis(FTA).A fault tree was constructed by considering four major areas where the le...This paper presents a probabilistic failure analysis of leakage of the oil and gas in a subsea production system using fault tree analysis(FTA).A fault tree was constructed by considering four major areas where the leakages can be initiated.These are:gas and oil wells,pipelines,key facilities and third party damage.Conventional FTA requires precise values for the probability of failure of the basic events.However,since the failure data are uncertain,a fuzzy approach to these data is taken which leads to the so-called fuzzy fault tree analysis(FFTA),a method that employs expert elicitation and fuzzy set theories to calculate the failure probabilities of the intermediate events and the top event through identification of the minimal cut sets of the fault tree.A number of importance measures for minimal cut sets and the basic events have been obtained which helps to identify the nature of dependence of the top event on the basic events and thereby can identify the weakest links that may cause leakage in the subsea production system.展开更多
With a successful and rapid development of offshore wind industry and increased research activities on wave energy conversion in recent years,there is an interest in investigating the technological and economic feasib...With a successful and rapid development of offshore wind industry and increased research activities on wave energy conversion in recent years,there is an interest in investigating the technological and economic feasibility of combining offshore wind turbines(WTs)with wave energy converters(WECs).In the EU FP7 MARINA Platform project,three floating combined concepts,namely the spar torus combination(STC),the semi-submersible flap combination(SFC)and the oscillating water column(OWC)array with a wind turbine,were selected and studied in detail by numerical and experimental methods.This paper summarizes the numerical modeling and analysis of the two concepts:STC and SFC,the model tests at a 1:50 scale under simultaneous wave and wind excitation,as well as the comparison between the numerical and experimental results.Both operational and survival wind and wave conditions were considered.The numerical analysis was based on a time-domain global model using potential flow theory for hydrodynamics and blade element momentum theory(for SFC)or simplified thrust force model(for STC)for aerodynamics.Different techniques for model testing of combined wind and wave concepts were discussed with focus on modeling of wind turbines by disk or redesigned small-scale rotor and modeling of power take-off(PTO)system for wave energy conversion by pneumatic damper or hydraulic rotary damper.In order to reduce the uncertainty due to scaling,the numerical analysis was performed at model scale and both the numerical and experimental results were then up-scaled to full scale for comparison.The comparison shows that the current numerical model can well predict the responses(motions,PTO forces,power production)of the combined concepts for most of the cases.However,the linear hydrodynamic model is not adequate for the STC concept in extreme wave conditions with the torus fixed to the spar at the mean water level for which the wave slamming on the torus occurs and this requires further investigation.Moreover,based on a preliminary comparison of展开更多
When fuel efficiency is at stake,along with the reduction of the environmental foot print of air pollution,a need is presented to estimate a ship’s fuel consumption for a forthcoming voyage,and means for decision mak...When fuel efficiency is at stake,along with the reduction of the environmental foot print of air pollution,a need is presented to estimate a ship’s fuel consumption for a forthcoming voyage,and means for decision making and for cost saving.This paper suggests an operational approach for obtaining an accurate fuel consumption and speed curve,on the basis of major factors affecting it,namely,ship’s draft and displacement,weather force and direction,hull and propeller roughness.A statistical analysis on 418 noon reports of a Pure Car and Truck Carrier case ship is carried out and the influence of the above factors is calculated.As expected,stronger wind and head weather increases the fuel consumption,and the difference between several weather conditions could be quantified.A simple and accurate algorithm is proposed in order for ship owners,managers and operators to be in a position to apply the suggested method on their fleet.Finally,applications of the structured algorithm are introduced with examples,in estimating the fuel consumption of the case ship for a future voyage,and also the same for a sister ship.Furthermore,voyage planning in several scenarios is proposed in order to assist the stakeholders with decision making aimed to fuel saving and environmental friendliness of their ships.展开更多
The key purpose of the present research is to derive the exact solutions of nonlinear water wave equations(NLWWEs)in oceans through the invariant subspace scheme(ISS).In this respect,the NLWWEs which describe specific...The key purpose of the present research is to derive the exact solutions of nonlinear water wave equations(NLWWEs)in oceans through the invariant subspace scheme(ISS).In this respect,the NLWWEs which describe specific nonlinear waves are converted to a number of systems of ordinary differential equations(ODEs)such that the resulting systems can be efficiently handled by computer algebra systems.As an accomplishment,the performance of the well-designed ISS in extracting a group of exact solutions is formally confirmed.In the end,the stability analysis for the NLWWE is investigated through the linear stability scheme.展开更多
In Underwater Wireless Sensor Networks(UWSNs),the most important challenging issues are propagation delay,high error probability,high latency,high communication cost,limited bandwidth,limited memory,low packet deliver...In Underwater Wireless Sensor Networks(UWSNs),the most important challenging issues are propagation delay,high error probability,high latency,high communication cost,limited bandwidth,limited memory,low packet delivery ratio,and transmission loss.In our proposed work,the various efforts are taken to minimize the propagation delay and transmission loss during data transmission in an underwater environment.A hybrid mechanism is implemented to improve energy efficiency for faster data transmission in underwater WSN.In the underwater environment of acoustic channel condition,propagation delay and transmission loss lead to high complexity in accessing the information and also it is difficult to obtain the Channel Status Information(CSI).To address this problem,Ant Colony Optimization(ACO)routing with Markov Chain Monte Carlo(MCMC)algorithm is used and to capture the transmission loss in the MCMC approach,CSI Forecast Prediction(FP)algorithm is used.The experimental simulations are evaluated by utilizing the performance evaluation metrics such as Transmission Loss,Probability Density Function,Average Delay and Throughput.From the simulation results it is evident that the proposed algorithm,ACO-MCMC has recorded the minimum transmission loss,increase in probability density function,minimum average delay and maximum throughput of the network when compared to the existing algorithms.展开更多
In this paper,we find the solutions for fractional potential Korteweg-de Vries(p-KdV)and Benjamin equations using q-homotopy analysis transform method(q-HATM).The considered method is the mixture of q-homotopy analysi...In this paper,we find the solutions for fractional potential Korteweg-de Vries(p-KdV)and Benjamin equations using q-homotopy analysis transform method(q-HATM).The considered method is the mixture of q-homotopy analysis method and Laplace transform,and the Caputo fractional operator is considered in the present investigation.The projected solution procedure manipulates and controls the obtained results in a large admissible domain.Further,it offers a simple algorithm to adjust the convergence province of the obtained solution.To validate the q-HATM is accurate and reliable,the numerical simulations have been conducted for both equations and the outcomes are revealed through the plots and tables.Comparison between the obtained solutions with the exact solutions exhibits that,the considered method is efficient and effective in solving nonlinear problems associated with science and technology.展开更多
In this article,the(1/G')-expansion method,the Bernoulli sub-ordinary differential equation method and the modified Kudryashov method are implemented to construct a variety of novel analytical solutions to the(3+1...In this article,the(1/G')-expansion method,the Bernoulli sub-ordinary differential equation method and the modified Kudryashov method are implemented to construct a variety of novel analytical solutions to the(3+1)-dimensional Boiti-Leon-Manna-Pempinelli model representing the wave propagation through incompressible fluids.The linearization of the wave structure in shallow water necessitates more critical wave capacity conditions than it does in deep water,and the strong nonlinear properties are perceptible.Some novel travelling wave solutions have been observed including solitons,kink,periodic and rational solutions with the aid of the latest computing tools such as Mathematica or Maple.The physical and analytical properties of several families of closed-form solutions or exact solutions and rational form function solutions to the(3+1)-dimensional Boiti-Leon-Manna-Pempinelli model problem are examined using Mathematica.展开更多
A new fractional 6D chaotic model is constructed in this paper.The new fractional 6D chaotic model has six positive parameters plus the fractional order with eight nonlinear terms.The complicated chaotic dy-namics of ...A new fractional 6D chaotic model is constructed in this paper.The new fractional 6D chaotic model has six positive parameters plus the fractional order with eight nonlinear terms.The complicated chaotic dy-namics of the new fractional 6D model is presented and analyzed.The basic properties of this model are studied and its chaotic attractors,dissipative feature,symmetry,equilibrium points,Lyapunov Exponents are investigated.The new dynamics of the 6D fractional model is numerically simulated using Matlab software.In addition,utilizing the graph theory tools certain structural characteristics are calculated.An electrical circuit is built to implement the new 5.4 fractional order 6D model.Finally,an active fractional order controller is proposed to control the new model at different fractional orders.The chaos of the new model is very useful and can be used to produce random keys for data encryption.展开更多
The nonlinear evolution equations have a wide range of applications,more precisely in physics,biology,chemistry and engineering fields.This domain serves as a point of interest to a large extent in the world’s mathem...The nonlinear evolution equations have a wide range of applications,more precisely in physics,biology,chemistry and engineering fields.This domain serves as a point of interest to a large extent in the world’s mathematical community.Thus,this paper purveys an analytical study of a generalized extended(2+1)-dimensional quantum Zakharov-Kuznetsov equation with power-law nonlinearity in oceanography and ocean engineering.The Lie group theory of differential equations is utilized to compute an optimal system of one dimension for the Lie algebra of the model.We further reduce the equation using the subalgebras obtained.Besides,more general solutions of the underlying equation are secured for some special cases of n with the use of extended Jacobi function expansion technique.Consequently,we secure new bounded and unbounded solutions of interest for the equation in various solitonic structures including bright,dark,periodic(cnoidal and snoidal),compact-type as well as singular solitons.The applications of cnoidal and snoidal waves of the model in oceanography and ocean engineering for the first time,are outlined with suitable diagrams.This can be of interest to oceanographers and ocean engineers for future analysis.Furthermore,to visualize the dynamics of the results found,we present the graphic display of each of the solutions.Conclusively,we construct conservation laws of the understudy equation via the application of Noether’s theorem.展开更多
The system of(1+1)-coupled Drinfel’d-Sokolov-Wilson equations describes the surface gravity waves travelling horizontally on the seabed.The objective of the present research is to construct a new variety of analytica...The system of(1+1)-coupled Drinfel’d-Sokolov-Wilson equations describes the surface gravity waves travelling horizontally on the seabed.The objective of the present research is to construct a new variety of analytical solutions for the system.The invariants are derived with the aid of Killing form by using the optimal algebra classification via Lie symmetry approach.The invariant solutions involve time,space variables,and arbitrary constants.Imposing adequate constraints on arbitrary constants,solutions are represented graphically to make them more applicable in designing sea models.The behavior of solutions shows asymptotic,bell-shaped,bright and dark soliton,bright soliton,parabolic,bright and kink,kink,and periodic nature.The constructed results are novel as the reported results[26,28,29,30,33,38,42,49]can be deduced from the results derived in this study.The remaining solutions derived in this study,are absolutely different from the earlier findings.In this study,the physical character of analytical solutions of the system could aid coastal engineers in creating models of beaches and ports.展开更多
In this paper,the(3+1)-dimensional nonlinear evolution equation is studied analytically.The bilinear form of given model is achieved by using the Hirota bilinear method.As a result,the lump waves and col-lisions betwe...In this paper,the(3+1)-dimensional nonlinear evolution equation is studied analytically.The bilinear form of given model is achieved by using the Hirota bilinear method.As a result,the lump waves and col-lisions between lumps and periodic waves,the collision among lump wave and single,double-kink soliton solutions as well as the collision between lump,periodic,and single,double-kink soliton solutions for the given model are constructed.Furthermore,some new traveling wave solutions are developed by applying the exp(−φ(ξ))expansion method.The 3D,2D and contours plots are drawn to demonstrate the nature of the nonlinear model for setting appropriate set of parameters.As a result,a collection of bright,dark,periodic,rational function and elliptic function solutions are established.The applied strategies appear to be more powerful and efficient approaches to construct some new traveling wave structures for various contemporary models of recent era.展开更多
A soliton is a packet of self-reinforcing waves that maintains its structure when moving at a constant speed.Solitons are caused by the cancellation of the medium’s nonlinear and dispersive effects.In plas-mas,the bi...A soliton is a packet of self-reinforcing waves that maintains its structure when moving at a constant speed.Solitons are caused by the cancellation of the medium’s nonlinear and dispersive effects.In plas-mas,the bilinear form of Hirota will be utilized to investigate the(2+1)-dimensional Korteweg-de Vries equation with electrostatic wave potential.Solutions for complexiton lump interaction have been devel-oped.To throw further light on the physical qualities of the recorded data,certain 3-dimensional and contour plots are presented to illustrate the interaction elements of these solutions.展开更多
In this research article,the(3+1)-dimensional nonlinear Gardner-Kadomtsov-Petviashvili(Gardner-KP)equation which depicts the nonlinear modulation of periodic waves,is analyzed through the Lie group-theoretic technique...In this research article,the(3+1)-dimensional nonlinear Gardner-Kadomtsov-Petviashvili(Gardner-KP)equation which depicts the nonlinear modulation of periodic waves,is analyzed through the Lie group-theoretic technique.Considering the Lie invariance condition,we find the symmetry generators.The pro-posed model yields eight-dimensional Lie algebra.Moreover,an optimal system of sub-algebras is com-puted,and similarity reductions are made.The considered nonlinear partial differential equation is re-duced into ordinary differential equations(ODEs)by utilizing the similarity transformation method(STM),which has the benefit of yielding a large number of accurate traveling wave solutions.These ODEs are further solved to get closed-form solutions of the Gardner-KP equation in some cases,while in other cases,we use the new auxiliary equation method to get its soliton solutions.The evolution profiles of the obtained solutions are examined graphically under the appropriate selection of arbitrary parameters.展开更多
New analytical solutions are derived to estimate the interaction of surface and groundwater in a stream-aquifer system.The analytical model consists of an unconfined sloping aquifer of semi-infinite extant,interacting...New analytical solutions are derived to estimate the interaction of surface and groundwater in a stream-aquifer system.The analytical model consists of an unconfined sloping aquifer of semi-infinite extant,interacting with a stream of varying water level in the presence of a thin vertical sedimentary layer of lesser hydraulic conductivity.Flow of subsurface seepage is characterized by a nonlinear Boussinesq equation subjected to mixed boundary conditions,including a nonlinear Cauchy boundary condition to approximate the flow through the sedimentary layer.Closed form analytical expressions for water head,discharge rate and volumetric exchange are derived by solving the linearized Boussinesq equation using Laplace transform technique.Asymptotic cases such as zero slope,absence of vertical clogging layer and abrupt change in stream-stage can be derived from the main results by taming one or more parameters.Analytical solutions of the linearized Boussinesq equation are compared with numerical solution of corresponding nonlinear equation to assess the validity of the linearization.Advantages of using a nonlinear Robin boundary condition,and combined effects of aquifer parameters on the bank storage characteristic of the aquifer are illustrated with a numerical example.展开更多
In the present paper,we build the new analytical exact solutions of a nonlinear differential equation,specifically,coupled Boussinesq-Burgers equations by means of Exp-function method.Then,we analyze the results by pl...In the present paper,we build the new analytical exact solutions of a nonlinear differential equation,specifically,coupled Boussinesq-Burgers equations by means of Exp-function method.Then,we analyze the results by plotting the three dimensional soliton graphs for each case,which exhibit the simplicity and effectiveness of the proposed method.The primary purpose of this paper is to employ a new approach,which allows us victorious and efficient derivation of the new analytical exact solutions for the coupled Boussinesq-Burgers equations.展开更多
The water impact and subsequent entry of three rigid axisymmetric bodies,a sphere and two cones,in the early phase are simulated using CFD utilizing a VOF scheme to track the free surface and the results compared with...The water impact and subsequent entry of three rigid axisymmetric bodies,a sphere and two cones,in the early phase are simulated using CFD utilizing a VOF scheme to track the free surface and the results compared with the recent experimental results available in the literature.The penetration depth,vertical velocity and vertical acceleration time histories have been reproduced well by CFD with a wide choice of mesh density,whereas the peak pressure on impact required a much finer mesh and appropriate choice of the time step.Delineating an interaction region around the trajectory of the body with fine mesh and an adaptive time stepping strategy has worked well to capture the peak impact pressure accurately with reasonable computational effort.The‘full’motion of the sphere,which is buoyant,has also been simulated using CFD allowing its 6-dof motion for several cycles of entry and exit phases.The features of the behavior,especially the loss of symmetry of the trajectory,are discussed.展开更多
In the organizational context of marine engineering,employee individual often prefers to concentrate herself to the day-to-day routine job,but to shirk the responsibilities of the Information Security Policies(ISPs)co...In the organizational context of marine engineering,employee individual often prefers to concentrate herself to the day-to-day routine job,but to shirk the responsibilities of the Information Security Policies(ISPs)compliance,after she has been delegated by the employer to perform the two different tasks in the same time period.This would lead to negative influences on the security of marine information systems and the employee’s routine job performance.In view of the task structures of employee’s routine job and marine ISPs compliance,the variables of emphasis on scheduling are incorporated into a multi-task principal-agent model to explore the optimal incentive scheme to motivate and control the employees to select appropriate effort levels for conducting the two highly structured tasks.The role of emphasis on scheduling on the incentive intensities for the two tasks have been clarified through modeling and simulation,and the corresponding incentive tactics are suggested.The new two-task incentive scheme is expected to provide useful insight for understanding and controlling marine engineering employee’s routine job and ISPs compliance behavior.展开更多
In the organizational setting of marine engineering,a significant number of information security incidents have been arised from the employees’failure to comply with the information security policies(ISPs).This may b...In the organizational setting of marine engineering,a significant number of information security incidents have been arised from the employees’failure to comply with the information security policies(ISPs).This may be treated as a principal-agent problem with moral hazard between the employer and the employee for the practical compliance effort of an employee is not observable without high cost-.On the other hand,according to the deterrence theory,the employer and the employee are inherently self-interested beings.It is worth examining to what extent the employee is self-interested in the marine ISPs compliance context.Moreover,it is important to clarify the proper degree of severity of punishment in terms of the deterrent effect.In this study,a marine ISPs compliance game model has been proposed to evaluate the deterrence effect of punishment on the non-compliance behavior of employee individuals.It is found that in a non-punishment contract,the employee will decline to comply with the marine ISPs;but in a punishment contract,appropriate punishment will lead her to select the marine ISPs compliance effort level expected by the employer,and cause no potential backfire effect.展开更多
The Kortewegde Vries(KdV)equation represents the propagation of long waves in dispersive media,whereas the cubic nonlinear Schrödinger(CNLS)equation depicts the dynamics of narrow-bandwidth wave packets consistin...The Kortewegde Vries(KdV)equation represents the propagation of long waves in dispersive media,whereas the cubic nonlinear Schrödinger(CNLS)equation depicts the dynamics of narrow-bandwidth wave packets consisting of short dispersive waves.A model that couples these two equations seems in-triguing for simulating the interaction of long and short waves,which is important in many domains of applied sciences and engineering,and such a system has been investigated in recent decades.This work uses a modified Sardar sub-equation procedure to secure the soliton-type solutions of the generalized cubic nonlinear Schrödinger-Korteweg-de Vries system of equations.For various selections of arbitrary parameters in these solutions,the dynamic properties of some acquired solutions are represented graph-ically and analyzed.In particular,the dynamics of the bright solitons,dark solitons,mixed bright-dark solitons,W-shaped solitons,M-shaped solitons,periodic waves,and other soliton-type solutions.Our re-sults demonstrated that the proposed technique is highly efficient and effective for the aforementioned problems,as well as other nonlinear problems that may arise in the fields of mathematical physics and engineering.展开更多
To realize the application of the floating offshore wind turbine(FOWT)from deep to relatively shallow waters,a new concept of multi-column floating wind turbine platform with low center of gravity(CG)is designed and v...To realize the application of the floating offshore wind turbine(FOWT)from deep to relatively shallow waters,a new concept of multi-column floating wind turbine platform with low center of gravity(CG)is designed and validated.The multi-column low CG platform is designed to support a 6MW wind turbine class and operated at a water depth of 50m in the South China Sea.The frequency domain software WADAM and time domain software NREL-FAST are used to simulate coupled dynamic responses of the floating wind turbine system with second-order wave loads considering.The dynamic behaviors of multi-column low CG FOWT system under normal operation and parked conditions are presented.The influence of second-order wave force on the motion responses of the multi-column platform,fore-aft force and moment of the tower base and mooring force are researched respectively.The results demonstrate that the coupled dynamic responses at rated operating condition and extreme condition meet the normal operating requirements and extreme survival requirements of FOWT system in the shallow water(50m)of South China Sea.In addition,it is found that,the wave frequency response gradually replaces the second-order low frequency response as the main influencing factor of the coupled dynamic response of the FOWT system with the increasing severity of the sea states.However,in general,the magnitude of second-order low frequency response increases with the increasing severity of the design load case.Thus,in the subsequent design of the shallow water FOWT system,the second-order effects should be paid enough attention.展开更多
文摘This paper presents a probabilistic failure analysis of leakage of the oil and gas in a subsea production system using fault tree analysis(FTA).A fault tree was constructed by considering four major areas where the leakages can be initiated.These are:gas and oil wells,pipelines,key facilities and third party damage.Conventional FTA requires precise values for the probability of failure of the basic events.However,since the failure data are uncertain,a fuzzy approach to these data is taken which leads to the so-called fuzzy fault tree analysis(FFTA),a method that employs expert elicitation and fuzzy set theories to calculate the failure probabilities of the intermediate events and the top event through identification of the minimal cut sets of the fault tree.A number of importance measures for minimal cut sets and the basic events have been obtained which helps to identify the nature of dependence of the top event on the basic events and thereby can identify the weakest links that may cause leakage in the subsea production system.
文摘With a successful and rapid development of offshore wind industry and increased research activities on wave energy conversion in recent years,there is an interest in investigating the technological and economic feasibility of combining offshore wind turbines(WTs)with wave energy converters(WECs).In the EU FP7 MARINA Platform project,three floating combined concepts,namely the spar torus combination(STC),the semi-submersible flap combination(SFC)and the oscillating water column(OWC)array with a wind turbine,were selected and studied in detail by numerical and experimental methods.This paper summarizes the numerical modeling and analysis of the two concepts:STC and SFC,the model tests at a 1:50 scale under simultaneous wave and wind excitation,as well as the comparison between the numerical and experimental results.Both operational and survival wind and wave conditions were considered.The numerical analysis was based on a time-domain global model using potential flow theory for hydrodynamics and blade element momentum theory(for SFC)or simplified thrust force model(for STC)for aerodynamics.Different techniques for model testing of combined wind and wave concepts were discussed with focus on modeling of wind turbines by disk or redesigned small-scale rotor and modeling of power take-off(PTO)system for wave energy conversion by pneumatic damper or hydraulic rotary damper.In order to reduce the uncertainty due to scaling,the numerical analysis was performed at model scale and both the numerical and experimental results were then up-scaled to full scale for comparison.The comparison shows that the current numerical model can well predict the responses(motions,PTO forces,power production)of the combined concepts for most of the cases.However,the linear hydrodynamic model is not adequate for the STC concept in extreme wave conditions with the torus fixed to the spar at the mean water level for which the wave slamming on the torus occurs and this requires further investigation.Moreover,based on a preliminary comparison of
文摘When fuel efficiency is at stake,along with the reduction of the environmental foot print of air pollution,a need is presented to estimate a ship’s fuel consumption for a forthcoming voyage,and means for decision making and for cost saving.This paper suggests an operational approach for obtaining an accurate fuel consumption and speed curve,on the basis of major factors affecting it,namely,ship’s draft and displacement,weather force and direction,hull and propeller roughness.A statistical analysis on 418 noon reports of a Pure Car and Truck Carrier case ship is carried out and the influence of the above factors is calculated.As expected,stronger wind and head weather increases the fuel consumption,and the difference between several weather conditions could be quantified.A simple and accurate algorithm is proposed in order for ship owners,managers and operators to be in a position to apply the suggested method on their fleet.Finally,applications of the structured algorithm are introduced with examples,in estimating the fuel consumption of the case ship for a future voyage,and also the same for a sister ship.Furthermore,voyage planning in several scenarios is proposed in order to assist the stakeholders with decision making aimed to fuel saving and environmental friendliness of their ships.
文摘The key purpose of the present research is to derive the exact solutions of nonlinear water wave equations(NLWWEs)in oceans through the invariant subspace scheme(ISS).In this respect,the NLWWEs which describe specific nonlinear waves are converted to a number of systems of ordinary differential equations(ODEs)such that the resulting systems can be efficiently handled by computer algebra systems.As an accomplishment,the performance of the well-designed ISS in extracting a group of exact solutions is formally confirmed.In the end,the stability analysis for the NLWWE is investigated through the linear stability scheme.
文摘In Underwater Wireless Sensor Networks(UWSNs),the most important challenging issues are propagation delay,high error probability,high latency,high communication cost,limited bandwidth,limited memory,low packet delivery ratio,and transmission loss.In our proposed work,the various efforts are taken to minimize the propagation delay and transmission loss during data transmission in an underwater environment.A hybrid mechanism is implemented to improve energy efficiency for faster data transmission in underwater WSN.In the underwater environment of acoustic channel condition,propagation delay and transmission loss lead to high complexity in accessing the information and also it is difficult to obtain the Channel Status Information(CSI).To address this problem,Ant Colony Optimization(ACO)routing with Markov Chain Monte Carlo(MCMC)algorithm is used and to capture the transmission loss in the MCMC approach,CSI Forecast Prediction(FP)algorithm is used.The experimental simulations are evaluated by utilizing the performance evaluation metrics such as Transmission Loss,Probability Density Function,Average Delay and Throughput.From the simulation results it is evident that the proposed algorithm,ACO-MCMC has recorded the minimum transmission loss,increase in probability density function,minimum average delay and maximum throughput of the network when compared to the existing algorithms.
文摘In this paper,we find the solutions for fractional potential Korteweg-de Vries(p-KdV)and Benjamin equations using q-homotopy analysis transform method(q-HATM).The considered method is the mixture of q-homotopy analysis method and Laplace transform,and the Caputo fractional operator is considered in the present investigation.The projected solution procedure manipulates and controls the obtained results in a large admissible domain.Further,it offers a simple algorithm to adjust the convergence province of the obtained solution.To validate the q-HATM is accurate and reliable,the numerical simulations have been conducted for both equations and the outcomes are revealed through the plots and tables.Comparison between the obtained solutions with the exact solutions exhibits that,the considered method is efficient and effective in solving nonlinear problems associated with science and technology.
文摘In this article,the(1/G')-expansion method,the Bernoulli sub-ordinary differential equation method and the modified Kudryashov method are implemented to construct a variety of novel analytical solutions to the(3+1)-dimensional Boiti-Leon-Manna-Pempinelli model representing the wave propagation through incompressible fluids.The linearization of the wave structure in shallow water necessitates more critical wave capacity conditions than it does in deep water,and the strong nonlinear properties are perceptible.Some novel travelling wave solutions have been observed including solitons,kink,periodic and rational solutions with the aid of the latest computing tools such as Mathematica or Maple.The physical and analytical properties of several families of closed-form solutions or exact solutions and rational form function solutions to the(3+1)-dimensional Boiti-Leon-Manna-Pempinelli model problem are examined using Mathematica.
基金support and funding of Research Center for Advanced Material Science(RCAMS)at King Khalid Uni-versity through Grant No.RCAMS/KKU/009-21.
文摘A new fractional 6D chaotic model is constructed in this paper.The new fractional 6D chaotic model has six positive parameters plus the fractional order with eight nonlinear terms.The complicated chaotic dy-namics of the new fractional 6D model is presented and analyzed.The basic properties of this model are studied and its chaotic attractors,dissipative feature,symmetry,equilibrium points,Lyapunov Exponents are investigated.The new dynamics of the 6D fractional model is numerically simulated using Matlab software.In addition,utilizing the graph theory tools certain structural characteristics are calculated.An electrical circuit is built to implement the new 5.4 fractional order 6D model.Finally,an active fractional order controller is proposed to control the new model at different fractional orders.The chaos of the new model is very useful and can be used to produce random keys for data encryption.
文摘The nonlinear evolution equations have a wide range of applications,more precisely in physics,biology,chemistry and engineering fields.This domain serves as a point of interest to a large extent in the world’s mathematical community.Thus,this paper purveys an analytical study of a generalized extended(2+1)-dimensional quantum Zakharov-Kuznetsov equation with power-law nonlinearity in oceanography and ocean engineering.The Lie group theory of differential equations is utilized to compute an optimal system of one dimension for the Lie algebra of the model.We further reduce the equation using the subalgebras obtained.Besides,more general solutions of the underlying equation are secured for some special cases of n with the use of extended Jacobi function expansion technique.Consequently,we secure new bounded and unbounded solutions of interest for the equation in various solitonic structures including bright,dark,periodic(cnoidal and snoidal),compact-type as well as singular solitons.The applications of cnoidal and snoidal waves of the model in oceanography and ocean engineering for the first time,are outlined with suitable diagrams.This can be of interest to oceanographers and ocean engineers for future analysis.Furthermore,to visualize the dynamics of the results found,we present the graphic display of each of the solutions.Conclusively,we construct conservation laws of the understudy equation via the application of Noether’s theorem.
文摘The system of(1+1)-coupled Drinfel’d-Sokolov-Wilson equations describes the surface gravity waves travelling horizontally on the seabed.The objective of the present research is to construct a new variety of analytical solutions for the system.The invariants are derived with the aid of Killing form by using the optimal algebra classification via Lie symmetry approach.The invariant solutions involve time,space variables,and arbitrary constants.Imposing adequate constraints on arbitrary constants,solutions are represented graphically to make them more applicable in designing sea models.The behavior of solutions shows asymptotic,bell-shaped,bright and dark soliton,bright soliton,parabolic,bright and kink,kink,and periodic nature.The constructed results are novel as the reported results[26,28,29,30,33,38,42,49]can be deduced from the results derived in this study.The remaining solutions derived in this study,are absolutely different from the earlier findings.In this study,the physical character of analytical solutions of the system could aid coastal engineers in creating models of beaches and ports.
文摘In this paper,the(3+1)-dimensional nonlinear evolution equation is studied analytically.The bilinear form of given model is achieved by using the Hirota bilinear method.As a result,the lump waves and col-lisions between lumps and periodic waves,the collision among lump wave and single,double-kink soliton solutions as well as the collision between lump,periodic,and single,double-kink soliton solutions for the given model are constructed.Furthermore,some new traveling wave solutions are developed by applying the exp(−φ(ξ))expansion method.The 3D,2D and contours plots are drawn to demonstrate the nature of the nonlinear model for setting appropriate set of parameters.As a result,a collection of bright,dark,periodic,rational function and elliptic function solutions are established.The applied strategies appear to be more powerful and efficient approaches to construct some new traveling wave structures for various contemporary models of recent era.
文摘A soliton is a packet of self-reinforcing waves that maintains its structure when moving at a constant speed.Solitons are caused by the cancellation of the medium’s nonlinear and dispersive effects.In plas-mas,the bilinear form of Hirota will be utilized to investigate the(2+1)-dimensional Korteweg-de Vries equation with electrostatic wave potential.Solutions for complexiton lump interaction have been devel-oped.To throw further light on the physical qualities of the recorded data,certain 3-dimensional and contour plots are presented to illustrate the interaction elements of these solutions.
基金The authors would like to thank the Deanship of Scientific Research at Majmaah University for supporting this work under Project R-2022-178.
文摘In this research article,the(3+1)-dimensional nonlinear Gardner-Kadomtsov-Petviashvili(Gardner-KP)equation which depicts the nonlinear modulation of periodic waves,is analyzed through the Lie group-theoretic technique.Considering the Lie invariance condition,we find the symmetry generators.The pro-posed model yields eight-dimensional Lie algebra.Moreover,an optimal system of sub-algebras is com-puted,and similarity reductions are made.The considered nonlinear partial differential equation is re-duced into ordinary differential equations(ODEs)by utilizing the similarity transformation method(STM),which has the benefit of yielding a large number of accurate traveling wave solutions.These ODEs are further solved to get closed-form solutions of the Gardner-KP equation in some cases,while in other cases,we use the new auxiliary equation method to get its soliton solutions.The evolution profiles of the obtained solutions are examined graphically under the appropriate selection of arbitrary parameters.
文摘New analytical solutions are derived to estimate the interaction of surface and groundwater in a stream-aquifer system.The analytical model consists of an unconfined sloping aquifer of semi-infinite extant,interacting with a stream of varying water level in the presence of a thin vertical sedimentary layer of lesser hydraulic conductivity.Flow of subsurface seepage is characterized by a nonlinear Boussinesq equation subjected to mixed boundary conditions,including a nonlinear Cauchy boundary condition to approximate the flow through the sedimentary layer.Closed form analytical expressions for water head,discharge rate and volumetric exchange are derived by solving the linearized Boussinesq equation using Laplace transform technique.Asymptotic cases such as zero slope,absence of vertical clogging layer and abrupt change in stream-stage can be derived from the main results by taming one or more parameters.Analytical solutions of the linearized Boussinesq equation are compared with numerical solution of corresponding nonlinear equation to assess the validity of the linearization.Advantages of using a nonlinear Robin boundary condition,and combined effects of aquifer parameters on the bank storage characteristic of the aquifer are illustrated with a numerical example.
文摘In the present paper,we build the new analytical exact solutions of a nonlinear differential equation,specifically,coupled Boussinesq-Burgers equations by means of Exp-function method.Then,we analyze the results by plotting the three dimensional soliton graphs for each case,which exhibit the simplicity and effectiveness of the proposed method.The primary purpose of this paper is to employ a new approach,which allows us victorious and efficient derivation of the new analytical exact solutions for the coupled Boussinesq-Burgers equations.
文摘The water impact and subsequent entry of three rigid axisymmetric bodies,a sphere and two cones,in the early phase are simulated using CFD utilizing a VOF scheme to track the free surface and the results compared with the recent experimental results available in the literature.The penetration depth,vertical velocity and vertical acceleration time histories have been reproduced well by CFD with a wide choice of mesh density,whereas the peak pressure on impact required a much finer mesh and appropriate choice of the time step.Delineating an interaction region around the trajectory of the body with fine mesh and an adaptive time stepping strategy has worked well to capture the peak impact pressure accurately with reasonable computational effort.The‘full’motion of the sphere,which is buoyant,has also been simulated using CFD allowing its 6-dof motion for several cycles of entry and exit phases.The features of the behavior,especially the loss of symmetry of the trajectory,are discussed.
文摘In the organizational context of marine engineering,employee individual often prefers to concentrate herself to the day-to-day routine job,but to shirk the responsibilities of the Information Security Policies(ISPs)compliance,after she has been delegated by the employer to perform the two different tasks in the same time period.This would lead to negative influences on the security of marine information systems and the employee’s routine job performance.In view of the task structures of employee’s routine job and marine ISPs compliance,the variables of emphasis on scheduling are incorporated into a multi-task principal-agent model to explore the optimal incentive scheme to motivate and control the employees to select appropriate effort levels for conducting the two highly structured tasks.The role of emphasis on scheduling on the incentive intensities for the two tasks have been clarified through modeling and simulation,and the corresponding incentive tactics are suggested.The new two-task incentive scheme is expected to provide useful insight for understanding and controlling marine engineering employee’s routine job and ISPs compliance behavior.
基金funded in part by the National Natural Science Foundation of China (No.70972058,No.71272092 and No.71431002)。
文摘In the organizational setting of marine engineering,a significant number of information security incidents have been arised from the employees’failure to comply with the information security policies(ISPs).This may be treated as a principal-agent problem with moral hazard between the employer and the employee for the practical compliance effort of an employee is not observable without high cost-.On the other hand,according to the deterrence theory,the employer and the employee are inherently self-interested beings.It is worth examining to what extent the employee is self-interested in the marine ISPs compliance context.Moreover,it is important to clarify the proper degree of severity of punishment in terms of the deterrent effect.In this study,a marine ISPs compliance game model has been proposed to evaluate the deterrence effect of punishment on the non-compliance behavior of employee individuals.It is found that in a non-punishment contract,the employee will decline to comply with the marine ISPs;but in a punishment contract,appropriate punishment will lead her to select the marine ISPs compliance effort level expected by the employer,and cause no potential backfire effect.
文摘The Kortewegde Vries(KdV)equation represents the propagation of long waves in dispersive media,whereas the cubic nonlinear Schrödinger(CNLS)equation depicts the dynamics of narrow-bandwidth wave packets consisting of short dispersive waves.A model that couples these two equations seems in-triguing for simulating the interaction of long and short waves,which is important in many domains of applied sciences and engineering,and such a system has been investigated in recent decades.This work uses a modified Sardar sub-equation procedure to secure the soliton-type solutions of the generalized cubic nonlinear Schrödinger-Korteweg-de Vries system of equations.For various selections of arbitrary parameters in these solutions,the dynamic properties of some acquired solutions are represented graph-ically and analyzed.In particular,the dynamics of the bright solitons,dark solitons,mixed bright-dark solitons,W-shaped solitons,M-shaped solitons,periodic waves,and other soliton-type solutions.Our re-sults demonstrated that the proposed technique is highly efficient and effective for the aforementioned problems,as well as other nonlinear problems that may arise in the fields of mathematical physics and engineering.
基金support from the National Natural Science Foundation of China (No.51809170 and No.12102210)State Key Laboratory of Ocean Engi-neering (No.GKZD010081)Programfor International Coopera-tion of Shanghai Science and Technology (No.18160744000).
文摘To realize the application of the floating offshore wind turbine(FOWT)from deep to relatively shallow waters,a new concept of multi-column floating wind turbine platform with low center of gravity(CG)is designed and validated.The multi-column low CG platform is designed to support a 6MW wind turbine class and operated at a water depth of 50m in the South China Sea.The frequency domain software WADAM and time domain software NREL-FAST are used to simulate coupled dynamic responses of the floating wind turbine system with second-order wave loads considering.The dynamic behaviors of multi-column low CG FOWT system under normal operation and parked conditions are presented.The influence of second-order wave force on the motion responses of the multi-column platform,fore-aft force and moment of the tower base and mooring force are researched respectively.The results demonstrate that the coupled dynamic responses at rated operating condition and extreme condition meet the normal operating requirements and extreme survival requirements of FOWT system in the shallow water(50m)of South China Sea.In addition,it is found that,the wave frequency response gradually replaces the second-order low frequency response as the main influencing factor of the coupled dynamic response of the FOWT system with the increasing severity of the sea states.However,in general,the magnitude of second-order low frequency response increases with the increasing severity of the design load case.Thus,in the subsequent design of the shallow water FOWT system,the second-order effects should be paid enough attention.
