Informed trading,heterogeneity investment,liquidity shocks and the valuation of credit default swaps

This paper explores the effect of informed trading, heterogeneity investment and liquidity shocks on the valuation of credit default swaps (CDSs). Under the condition of asymmetric information, the informed trading plays an important role in the valuation of CDS. Instruction order flow has a significant influence on CDS price. And the scope of influence changes in accordance with different time interval, company status and the size of bid-ask spread. Heterogeneity of investors seriously affects the market liquidity and subsequently affects the CDS price. The bigger heterogeneity of the investment philosophy, investment habits, investment preference and so on is the bigger risk for market liquidity, and the higher price for CDS shall be. On the contrary, the conclusion is also consistent. The effectiveness of liquidity, whether it is before or after the financial crisis, dominates the fluctuation of CDS price. The premium of liquidity accounts for 36% to 50% of the CDS price.     

Wind turbine gearbox reliability analysis based on the system level stress-strength model

In order to estimate the reliability of wind turbine gearbox based on the system level, a generalized stress-strength model is introduced. Considering that the system works properly under a variety of random stresses which affect every component, the total stress on the system is given by a known linear combination of the stresses of all components. Then the strength of the system can be viewed as a linear combination of the strengths of relative components. In this model, stress and strength are independent of each other. Reliability of the system is the probability that strength exceeds stress. Finally, the reliability of wind turbine gearbox is estimated by the multivariable reliability calculation method. The corresponding result is compared with the results of reliability in the extreme cases(completely dependent and completely independent) by the traditional evaluation method.     

A novel de-noising method based on discrete cosine transform and its application in the fault feature extraction of hydraulic pump

Aiming at the existing problems of discrete cosine transform (DCT) de-noising method, we introduce the idea of wavelet neighboring coefficients (WNC) de-noising method, and propose the cosine neighboring coefficients (CNC) de-noising method. Based on DCT, a novel method for the fault feature extraction of hydraulic pump is analyzed. The vibration signal of pump is de-noised with CNC de-noising method, and the fault feature is extracted by performing Hilbert-Huang transform (HHT) to the output signal. The analysis results of the simulation signal and the actual one demonstrate that the proposed CNC de-noising method and the fault feature extraction method have more superior ability than the traditional ones.     

Combustion optimization model for NO<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> reduction with an improved particle swarm optimization

Abstract: This paper focuses on the combustion optimization to cut down NO _x emission with a new strategy. Firstly, orthogonal experimental design (OED) and chaotic sequences are introduced to improve the performance of particle swarm optimization (PSO). Then, a predicting model for NO _x emission is established on support vector machine (SVM) whose parameters are optimized by the improved PSO. Afterwards, a new optimization model considering coal quantity and air quantity along with the traditional optimization variables is established. At last, the operating parameters are optimized by the improved PSO to cut down the NO _x emission. An application on 600MW unit shows that the new optimization model can cut down NO _x emission effectively and maintain the load balance well. The NO _x emission optimized by the improved PSO is lowest among some state-of-the-art intelligent algorithms. This study can provide important guides for the low NO _x combustion in the power plant.     

Robust principal component analysis via truncated nuclear norm minimization

Robust principal component analysis(PCA) is widely used in many applications, such as image processing, data mining and bioinformatics. The existing methods for solving the robust PCA are mostly based on nuclear norm minimization. Those methods simultaneously minimize all the singular values, and thus the rank cannot be well approximated in practice. We extend the idea of truncated nuclear norm regularization(TNNR) to the robust PCA and consider truncated nuclear norm minimization(TNNM) instead of nuclear norm minimization(NNM). This method only minimizes the smallest N-r singular values to preserve the low-rank components, where N is the number of singular values and r is the matrix rank. Moreover, we propose an effective way to determine r via the shrinkage operator. Then we develop an effective iterative algorithm based on the alternating direction method to solve this optimization problem. Experimental results demonstrate the efficiency and accuracy of the TNNM method. Moreover, this method is much more robust in terms of the rank of the reconstructed matrix and the sparsity of the error.     

Research on vane end face of cam-rotor vane servo motor based on disturbing torque

Cam-rotor vane motor (CRVM) is one of the new continuous hydraulic servo motors with the characteristics of no pulsation of instantaneous flow rate and output torque, small volume and rotating inertia. It is one of the appropriate actuators for hydraulic servo system which has good dynamic and steady-state performance requirements. The ideal output torque of CRVM is pulseless, but the actual output torque of CRVM is pulsating. This is caused by the disturbing torque of contact components, especially the friction between vane and cam-rotor. In order to get better performance of CRVM, which means more stable output torque and smaller disturbing torque, we discuss four kinds of vane end faces (VEFs). Analytic formulae of the normal contact force and the disturbing torque caused by the vane are derived from systematical force analysis. The normal contact force and the disturbing torque vary through a period under different VEF, and the reduced oil pressure is simulated in this paper. The simulation shows that the VEF with the proper round and reduced oil pressure can significantly decrease the disturbing torque and get better servo performance. The experiment results verify the correctness of the theoretical analysis and simulation.     

Construction of rate-compatible (RC) low-density parity-check (LDPC) convolutional codes based on RC-LDPC block codes

In this paper, a family of rate-compatible (RC) low-density parity-check (LDPC) convolutional codes can be obtained from RC-LDPC block codes by graph extension method. The resulted RC-LDPC convolutional codes, which are derived by permuting the matrices of the corresponding RC-LDPC block codes, are systematic and have maximum encoding memory. Simulation results show that the proposed RC-LDPC convolutional codes with belief propagation (BP) decoding collectively offer a steady improvement on performance compared with the block counterparts over the binary-input additive white Gaussian noise channels (BI-AWGNCs).     

Evolutionary game on oil and gas companies’ pollution treatment

This paper presents a dynamic model of pollution treatment strategies, driven by the bargaining relationships between governments, oil and gas companies and local residents. The results show that government plays a dominating role and government environmental policies have significant impact on other two parties’ behavior. To achieve better pollution treatment in the future, we put forward the following suggestions. An improvement in the legal system is required, and the legal enforcement needs to be strengthened. In terms of pollution treatment, responsibilities and obligations of these three parties need to be clearly defined. A wellfunctioned reward and penalties system needs to be established for minimizing the environment damage in the future.     

顶管穿越高速公路的设计与施工注意事项

该文结合工程实例简要介绍了顶管的设计、顶管的施工注意事项及顶管作业施工测量控制、顶管施工的优点及其发展潜力。     

三灰土路面底基层混合料配合比优化

结合三灰土路面底基层的施工实践,通过混合料的配合比设计和粘质土改良等措施,提出混合料不同掺配的控制方法。结果得出：适度加大混合料中粘质土的比例,降低了水泥用量,达到了降低成本的目的。