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A Time-Domain Numerical Simulation for Free Motion Responses of Two Ships Advancing in Head Waves

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China Ocean Engineering 2024年第3期38卷 519-530页

作者： pan su-yong CHENG Yong School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China

The constant panel method within the framework of potential flow theory in the time domain is developed for solving the hydrodynamic interactions between two parallel ships with forward *** solving problems within a time domain framework,the free water surface needs to simultaneously satisfy both the kinematic and dynamic boundary conditions of the free water *** provides conditions for adding artificial damping *** the Runge−Kutta method to solve equations related to *** upwind differential scheme is used in the present method to deal with the convection terms on the free surface to prevent waves *** the comparison with the available experimental data and other numerical methods,the present method is proved to have good mesh convergence,and satisfactory results can be *** constant panel method is applied to calculate the hydrodynamic interaction responses of two parallel ships advancing in head *** simulations are conducted on the effects of forward speed,different longitudinal and lateral distances on the motion response of two modified Wigley ships in head *** further investigations are conducted on the effects of different ship types on the motion response.

关键词： ship motions time domain simulation forward speed different distances wave loads

Service Migration Algorithm Based on Markov Decision Process with Multiple Service Types and Multiple System Factors

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Chinese Journal of Electronics 2024年第6期33卷 1515-1525页

作者： Anhua MA su pan Weiwei ZHOU Broadband Wireless Communication College Nanjing University of Posts and Telecommunications School of Computer Science and Technology Nanjing Tech University

This paper proposes a Markov decision process based service migration algorithm to satisfy quality of service(QoS) requirements when the terminals leave the original server. Services were divided into real-time services and non-real-time services, each type of them has different requirements on transmission bandwidth and latency,which were considered in the revenue function. Different values were assigned to the weight coefficients of QoS parameters for different service types in the revenue and cost functions so as to distinguish the differences between the two service types. The overall revenue was used for migration decisions, rather than fixed threshold or instant *** Markov decision process was used to maximize the overall revenue of the system. Simulation results show that the proposed algorithm obtained more revenue compared with the existing works.

关键词： Energy consumption Costs Markov decision processes Simulation Quality of service Market research Cost function Real-time systems Energy efficiency Servers

Time-Domain Higher-Order Boundary Element Method for Simulating High Forward-Speed Ship Motions in Waves

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China Ocean Engineering 2024年第5期38卷 904-914页

作者： ZHOU Xiao-guo CHENG Yong pan su-yong School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China

The hydrodynamic performance of a high forward-speed ship in obliquely propagating waves is numerically examined to assess both free motions and wave field in comparison with a low forward-speed *** numerical model is based on the time-domain potential flow theory and higher-order boundary element method,where an analytical expression is completely expanded to determine the base-unsteady coupling flow imposed on the moving condition of the *** ship in the numerical model may possess different advancing speeds,***,low speed,and high *** role of the water depth,wave height,wave period,and incident wave angle is analyzed by means of the accurate numerical *** is found that the resonant motions of the high forward-speed ship are triggered by comparison with the stationary *** specifically,a higher forward speed generates a V-shaped wave region with a larger elevation,which induces stronger resonant motions corresponding to larger wave *** shoaling effect is adverse to the motion of the low-speed ship,but is beneficial to the resonant motion of the high-speed *** waves obliquely propagate toward the ship,the V-shaped wave region would be broken due to the coupling effect between roll and pitch *** is also demonstrated that the maximum heave motion occurs in beam seas for stationary cases but occurs in head waves for high ***,the variation of the pitch motion with period is hardly affected by wave incident angles.

关键词： high forward speed oblique incident waves ship motion higher-order boundary element method time domain wave field

Cross-layer resource allocation based on equivalent bandwidth in OFDMA systems

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Journal of Systems Engineering and Electronics 2016年第4期27卷 754-762页

作者： su pan Cheng Li Sheng Zhang Danwei Chen Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts & Telecommunications

A quality of service（QoS） guaranteed cross-layer resource allocation algorithm with physical layer, medium access control（MAC） layer and call admission control（CAC） considered simultaneously is proposed for the full IP orthogonal frequency division multiple access（OFDMA） communication system, which can ensure the quality of multimedia services in full IP *** algorithm converts the physical layer resources such as subcarriers, transmission power, and the QoS metrics into equivalent bandwidth which can be distributed by the base station in all three layers. By this means, the QoS requirements in terms of bit error rate（BER）, transmission delay and dropping probability can be guaranteed by the cross-layer optimal equivalent bandwidth allocation. The numerical results show that the proposed algorithm has higher spectrum efficiency compared to the existing systems.

关键词： resource allocation equivalent bandwidth crosslayer optimization orthogonal frequency division multiple access(OFDMA)

A New Isogeometric Finite Element Method for Analyzing Structures

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Computer Modeling in Engineering & Sciences 2024年第11期141卷 1883-1905页

作者： pan su Jiaxing Chen Ronggang Yang Jiawei Xiang College of Power Engineering Naval University of EngineeringWuhan430033China College of Mechanical and Electrical Engineering Wenzhou UniversityWenzhou325035China

High-performance finite element research has always been a major focus of finite element method *** article introduces isogeometric analysis into the finite element method and proposes a new isogeometric finite element ***,the physical field is approximated by uniform B-spline interpolation,while geometry is represented by non-uniform rational B-spline *** introducing a transformation matrix,elements of types C^(0)and C^(1)are constructed in the isogeometric finite element ***,the corresponding calculation formats for one-dimensional bars,beams,and two-dimensional linear elasticity in the isogeometric finite element method are derived through variational principles and parameter *** proposed method combines element construction techniques of the finite element method with geometric construction techniques of isogeometric analysis,eliminating the need for mesh generation and maintaining flexibility in element *** elements with interpolation characteristics are constructed in the method so that boundary conditions and connections between elements can be processed like the finite element ***,the test results of several examples show that:(1)Under the same degree and element node numbers,the constructed elements are almost consistent with the results obtained by traditional finite element method;(2)For bar problems with large local field variations and beam problems with variable cross-sections,high-degree and multi-nodes elements constructed can achieve high computational accuracy with fewer degrees of freedom than finite element method;(3)The computational efficiency of isogeometric finite element method is higher than finite element method under similar degrees of freedom,while as degrees of freedom increase,the computational efficiency between the two is similar.

关键词： Finite element method isogeometric analysis uniform B-spline non-uniform rational B-spline beam and bar

Optimal Power Allocation with Limited Feedback of Channel State Information in Multi-User MIMO Systems

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China Communications 2020年第2期17卷 163-175页

作者： Kusi Ankrah Bonsu Weiwei Zhou su pan Yan Yan Key Lab Broadband Wireless Communication and Sensor Network Technology Ministry of EducationNanjing University of Posts and Telecommunications Nanjing 210003China Global Big Data Technologies Centre(GBDTC) University of Technology SydneySydney 2007Australia

In this paper,an expression for the user’s achievable data rate in the multi-user multiple-input multiple-output(MU-MIMO)system with limited feedback(LF)of channel state information(CSI)is *** energy efficiency(EE)is optimized through power allocation under quality of service(QoS)*** on mathematical equivalence and Lagrange multiplier approach,an energy-efficient unequal power allocation(EEUPA)with LF of CSI scheme is *** simulation results show that as the number of transmitting antennas increases,the EE also increases which is promising for the next generation wireless communication ***,it can be seen that the QoS requirement has an effect on the EE of the ***,the proposed EEUPA with LF of CSI algorithm performs better than the existing energy-efficient equal power allocation(EEEPA)with LF of CSI schemes.

关键词： energy efficiency unequal power allocation limited feedback MU-MIMO QoSguarantee and precoding

SAE-TOPSIS algorithm for vertical handoff decision in heterogeneous wireless networks

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High Technology Letters 2012年第4期18卷 382-386页

作者：刘胜美 pan su Mi Zhengkun Broadband Wireless Communication and Sensor Network Technology Key Laboratory of Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 P. R. China

An improved technique for order preference by similarity to ideal solution （TOPSIS） algorithm, SAE-TOPSIS, is proposed for the vertical handoff decision in heterogeneous wireless networks. The signal to interference plus noise ratio （SINR） effects, analytic hierarchy process （AHP） and infor- mation entropy （SAE） weight method were introduced into the algorithm. Handoff decision meeting the multi-attribute quality of service （QoS） requirement is made according to an attribute matrix and weight vector using the TOPSIS algorithm. The simulation results have shown that the proposed algo- rithm can provide satisfactory performance fitted to the characteristics of the traffic.

关键词： heterogeneous wireless networks vertical handoff technique for order preferenceby similarity to ideal solution (TOPSIS) analytic hierarchy process (AHP) entropy signal to in-terference plus noise ratio (SINR)

IMPROVING THE CAPACITY OF MULTI-CODE MULTIMEDIA CDMA SYSTEM

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Journal of Electronics(China) 2007年第4期24卷 557-559页

作者： pan su Liu Shengmei Dept of Telecommunications Engineering The Nanjing University of Posts ＆ Telecommunications Nanjing 210003 China National Mobile Communications Key Lab The Southeast University Nanjing 210096 China

A novel method for improving the capacity of multi-code multimedia Code Division Mul- tiple Access (CDMA) systems is proposed. By factitiously improving the transmission bit rate of the call, the number of the orthogonal codes used by a user is increased which leads to the decreasing of the interference. Simulation results shows that the proposed scheme results in better throughput than traditional multi-code CDMA systems.

关键词： Capacity Multimedia Code Division Multiple Access (CDMA)

Securing Patient-Centric Personal Health Records Sharing System in Cloud Computing

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China Communications 2014年第A01期11卷 121-127页

作者： CHEN Danwei CHEN Linling FAN Xiaowei HE Liwen pan su Hu Ruoxiang NanjingUniversityofPostsandTelecommunications Nanjing210003JiangsuProvinceER.China InformationSecurityCenter BeijingUniversityofPostsandTelecommunicationsBeijing100876China NationalEngineeringLaboratoryforDisasterBackupandRecovery Beijing100876China

Personal health record （PHR） enables patients to manage their own electronic medical records （EMR） in a centralized way, and it is oRen outsourced to be stored in a third-party server. In this paper we propose a novel secure and scalable system for sharing PHRs. We focus on the multiple data owner scenario, and divide the users in the system into multiple security domains that greatly reduce the key management complexity for owners and users. A high degree of patient privacy is guaranteed by exploiting hierarchical and multi- authority attribute-sets based encryption （HM- ASBE）. Our system not only supports compound attributes due to flexible attribute sets combinations, but also achieves fine-grained access control. Our scheme supports efficient on-demand user/attribute revocation and break-glass access under emergency scenarios.

关键词： personal health records attribute- based encryption data privacy fine-grained access control