Research on the railway construction process quality model based on the state space method

In the ISO9000"input-output"process model,the concept of process quality is difficult to get the correct interpretation. From the"white box"theory of process,this paper puts forward the scientific meaning of the concept of process quality and the process quality model by taking the basic operating unit of 6M1E in the railway construction project for example. The basic operating unit system consists of technological natural process,operation process and management process;the process quality of the basic operating unit system depends on the interrelation and interaction among those three sub-processes,and also subjects to the impact of the external disturbance input factors. Finally,the cast-in-situ prestressed concrete continuous box girder construction process is utilized to elaborate the specific application of this theory in the quality management of the railway construction project.

Pressure-induced phase transition of B-type Y_2O_3

The synthesized monoclinic（B-type） phase of Y2O3 has been investigated by in situ angle-dispersive x-ray diffraction in a diamond anvil cell up to 44 GPa at room temperature. A phase transition occurs from monoclinic（B-type） to hexagonal（A-type） phase at 23.5 GPa and these two phases coexist even at the highest pressure. Parameters of isothermal equation of state are V0= 69.0（1）A3, K0= 159（3） GPa, K0= 4（fixed） for the B-type phase and V0= 67.8（2） A3, K0= 156（3） GPa,K＇0= 4fixed for the A-type phase. The structural anisotropy increases with increasing pressure for both phases.

An efficient method for parallel CRC automatic generation

The State Transition Equation (STE) based method to automatically generate the parallel CRC circuits for any generator polynomial or required amount of parallelism is presented. The parallel CRC circuit so generated is partially optimized before being fed to synthesis tools and works properly in our LAN transceiv-er. Compared with the cascading method, the proposed method gives better timing results and significantly re-duces the synthesis time, in particular.

Dynamic State Estimation for Integrated Electricity-gas Systems Based on Kalman Filter

In recent years, integrated electricity-gas systems(IEGSs) have attracted widespread attention. The unifiedscheduling and control of the IEGS depends on high-precisionoperating data. To this end, it is necessary to establish anappropriate state estimation (SE) model for IEGS to filter theraw measured data. Considering that power systems and naturalgas systems have different time scales and sampling periods, thispaper proposes a dynamic state estimation (DSE) method basedon a Kalman filter that can consider the dynamic characteristicsof natural gas pipelines. First, the standardized state transitionequations for the gas system are developed by applying the finitedifference method to the partial differential equations (PDEs) ofthe gas system;then the DSE model for IEGS is formulatedbased on a Kalman filter;also, the measurements from theelectricity system and the gas system with different samplingperiods are fused to ensure the observability of DSE by using theinterpolation method. The IEEE 39-bus electricity system and the18-nodes Belgium gas system are integrated as the test systems.Simulation results verify the proposed method’s accuracy andcalculation efficiency.