In order to explore the fishery, oil and gas, and tourism resources in the ocean, Very Large Floating Structures (VLFS) can be deployed near islands and reefs as a logistic base with various functions such as a floating harbor, accommodation, fishery processing, oil and gas exploration, environment surveillance, airplane landing and taking off, etc. However, in addition to the complicated hydroelastic coupling effects between the hydrodynamic loads and structural dynamic responses, when tackling the hydroelastic problems of floating structures deployed near islands and reefs, several other environmental effects and numerical techniques should be taken into account: 1) The influences of the non-uniform incident waves (multi-directions, different wave frequencies); 2) Complex seabed profile and its impact on the incident waves; 3) Nonlinear second order wave exciting forces in the complex mooring system, shallow water and coral reef geological conditions; 4) Parallel computing technology and fast solving methods for the large scale linear equations, accounting for the influence of dramatic increase of number of meshes to the computation efforts and efficiency. In the present paper the theoretical investigation on the hydroelastic responses of VLFS deployed near islands and reefs has been presented. In addition, based on the pulsating source Green function, the high performance parallel fast computing techniques and other numerical methods, in solving large scale linear equations, have been introduced in the three-dimensional hydroelastic analysis package THAFTS. The motions, wave loads, distortions and stresses can be calculated using the present theoretical model and the results can be used in the design and safety assessment of VLFS.
As the source of power line project, line design is a key part of life cycle management. The safety and reliability of line design can provide necessary support for construction, operation and maintenance. This paper proposes a risk-based approach for safety management in line design, decomposing risks into two dimensions, the probability and the consequence. Based on factors, such as risk assessment, number of historical incidents, consequence of historical incidents, qualification of proofreading and auditing, this approach in line design can predict risk status in real time, provide scientific basis for risk control, and minimize safety hazards.
Using guided wave dispersion characteristics, a procedure based on articial neural network (ANN) is presented to inversely determine the elastic constants of orthotropic plate. The Legendre polynomial method is employed as the forward solver to calculate the dispersion curves of SH wave for orthotropic plates. The group velocities of lowest modes at five lower frequencies are used as the inputs for the ANN model. The outputs of the ANN are the elastic constants of orthotropic plates. This procedure is examined for an actual orthotropic plate. The results indicate that the identified elastic constants are sufficiently close to the original one. The developed inverse procedure is concluded to be robust and efficient.
Three-dimensional multistatic imaging is a powerful noninvasive examination tool for many military and civilian applications. Recently, the sparsity-regularized optimization has been used as a popular imaging technique to enhance the image quality. However, it suffers from the expensive computational cost, since its solution is obtained by a time-consuming iterative scheme, which is typically computationally prohibitive for large-scale imaging problems. To overcome this difficulty, this challenging imaging problem is converted into an image processing problem in this letter, which can be performed over small-scale overlapping patches and be efficiently solved in a parallel or distributed manner. In this way, the proposed qualitative scheme could be utilized to solve large-scale imaging problems. Exemplary simulation results are provided to demonstrate the efficiency of the proposed methodology.
Based on linear magneto-electro-elasticity, the circumferential SH wave equation of transversely isotropy piezoelectricity-piezomagnetic functionally graded cylindrical curved plate is obtained. The Legendre orthogonal polynomial series expansion approach is employed to derive its asymptotic solution. The dispersion curves, electric potential and magnetic potential distributions are calculated. The influence of the piezoelectricity and piezomagnetism on the circumferential SH wave is investigated and the influential factors are analyzed. Finally, the influence of the gradient field and the ratio of the radius to thickness on the piezoelectric effect and piezomagnetic effect are illustrated.
Family control system of further development information can use fully existing power net resource,which makes the system build reduce cost substantially,and it is shortcut and convenient.This paper discusses on the key technology of the smart home,X-10 carrier technology,and presents the application of smart home in contemporary life,for example,intelligent household alarm system and remote control system.
The technical characteristics of cloud computing and internet of things is introduced,and how to use the two techniques in supply chain management is elaborateed.Finally the problems which need to be aware when apply the technology and the values it brings when realize the technology are pointed out.
The zero-sequence directional protection on parallel lines will mal-operate for zero-sequence mutual inductance. An inductance model for an internal fault is established and a model error function is defined on model recognition theory by analyzing the fault equivalent circuit. The model error is small for an internal fault while large and oscillating for an external fault. To solve the problem caused by the high-frequency components in the transient waveform on the set threshold value of the proposed method, the power frequency component is used for the model error function in this paper. A new phasor extracting method named fast phasor extracting algorithm is introduced to extract the power frequency component during the transient period. Simulation results from EMTP prove the high quality of the improved zero-sequence directional element and its validity to pick up speed to remove the fault.
Traffic accidents are caused by a variety of factors, while major accident inducements are different for specific districts. Effective activities can be done to reduce potential traffic risk by studying the mechanisms of accident formation for a particular area. This paper applies a biochemical factorial experiment method to traffic accidents' inducement analysis, and describes the processes of modeling and data processing in detail. Causes and their additive effects that significantly affect the accident quantity of a specific district can be distinguished in this manner, while the traditional statistical method only provides some simple percentages. Strengths and weaknesses of this new idea are both discussed based on a simple illustration. Data processing is mostly done by SPSS in this paper.
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