Unscented Kalman filtering in the additive noise case

The unscented Kalman filter(UKF) has four implementations in the additive noise case,according to whether the state is augmented with noise vectors and whether a new set of sigma points is redrawn from the predicted state(which is so-called resampling) for the observation prediction.This paper concerns the differences of performances for those implementations,such as accuracy,adaptability,computational complexity,etc.The conditionally equivalent relationships between the augmented and non-augmented unscente...     

Reduced-order filtering for networks with Markovian jumping parameters and missing measurements

The problem of reduced-order H _∞ filters design for Markovian jumping complex networks with polytopic time-varying transition probability matrices is first addressed in this paper, where the dynamic of each node is described by the sector-bounded nonlinearity. For the measurements, both quantisation and packet dropouts are considered, where each node has its own packet dropout rate. By using the mode- and transition probability-dependent Lyapunov function approach, two sufficient conditions are provided to ensure the stochastic stability and the disturbance attenuation performance of the resulting filtering error system. Then, the mode-independent reduced-order filters design method is proposed, and the filter parameters are given explicitly by linear matrix inequality method. Finally, the effectiveness of the theoretic results presented is illustrated via a numerical example which contains performance comparison of different mode-independent reduced-order filters.     

Structural studies of a mixed-valence state in the incommensurate composite crystal Sr1.261CoO3

Abstract

The incommensurate modulated crystal structure of the hexagonal cobalt oxide Sr_1.261CoO₃ has been studied using a four-dimensional (4D) superspace profile analysis of neutron powder diffraction data. Sr_1.261CoO₃ is a composite crystal that consists of the [CoO₃] and [2Sr] subsystems. The [CoO₃] subsystem forms 1D chains that run parallel to the c-axis and consist of face-sharing CoO₆ polyhedra with octahedral (Oh) and trigonal prismatic (TP) coordinations. The structure analysis reveals that the [CoO₃] chains contain 73.9% Oh and 26.1% TP sites, and that the TP sites have longer Co–O bonds than the Oh sites: d_av. =2.039(4) Å (TP) and 1.895(3) Å (Oh). The averaged Co bond valences are Co^3.56(3)+ in the Oh sites and Co^2.45(3)+ in the TP sites, suggesting that a considerable amount of Co³⁺ ions are mixed with Co⁴⁺ions in the Oh sites and with Co²⁺ ions in the TP sites. The observed magnetic susceptibility can be well explained assuming that the compound has the Co mixed-valence state with the spin configurations of S=0 low-spin state for Co³⁺(dε⁶), S=1/2 low-spin state for Co⁴⁺(dε⁵) and S=3/2 high-spin state for Co²⁺(dε⁵dγ²). The Weiss temperature, approximately 0.8 K, implies that Sr_1.261CoO₃ naturally assumes a Curie paramagnetic state, probably owing to the obstruction of the intrachain magnetic interaction by the nonmagnetic Co³⁺ ions. These results suggest that the nonmagnetic Co³⁺ ions play an essential role in the magnetism of Sr_2γCoO₃ systems.     

Pulse-jet filtration: An effective way to control industrial pollution Part I: Theory,selection and design of pulse-jet filter

Pulse-jet filtration is described as one of the most efficient technologies in controlling industrial pollution across the world. The monograph provides the fundamental concept of design and development of pulse-jet filters under varied siutations. For successful running of a filter unit, a comprehensive knowledge base as regards a selection of design and development of filter media is essential; thus, this is incorporated in the monograph. I also discuss technical and commerically attractive solutions for successful operation of industries integrated with pollution control equipment maintaining clean air requirements.     

RE模型和AEG模型估值研究

对剩余收益模型（RE）和异常收益模型（AEG）在我国证券市场上的适用性进行了研究。首先对这两个模型进行了比较分析，然后根据分析师对北京银行的财务预测，用模型对其流通股价值进行了评估，并做了敏感性分析。在不考虑未来出现相关新信息的假设下，得出其在不同情景下的价值区间和相应的杠杆远期市盈率和杠杆市净率。     

A Correlation for Prediction of the Required Minimum External Surface Area of Gas Cartridge Filters in the Petroleum Industry

Abstract

A correlation has been derived from analytical solution of mass and momentum balance equations for accurate and rapid estimation of the required minimum external surface area of gas cartridge filters in the petroleum industry. The proposed correlation is especially important for preliminary design of these units regarding gas injection projects and underground storage of natural gas. High replacement costs associated with gas cartridge filters and numerous applications of these units are the most important justifications of the present work. Predicted results and fabricator's recommended data regarding the required minimum external surface area of gas cartridge filters are in good agreement with an average absolute deviation (AAD) of 2.4%.     

基于MSP430的硬件可控滤波电路设计

针对采用软件FFT算法实现的谐波检测占用CPU内存空间大、容易影响系统实时性的问题,提出了基于BPF硬件电路谐波检测的方法。根据实际应用中对定性分析和实时性的要求,对所需要的有源带通滤波器(BPF)和控制电路进行了反复测试,实现了对输入信号中部分奇次谐波的可控检测,提高了检测速度,保证了系统的稳定工作。     

Experimental and density functional theory studies on PtPb/C bimetallic electrocatalysts for methanol electrooxidation reaction in alkaline media

Carbon-supported bimetallic Pt_mPb₁ (m = 1, 2, 3) electrocatalysts with different Pt/Pb atomic ratios were synthesized by a polyol method. The X-ray diffraction results reveal that a PtPb alloy formed in the Pt_mPb₁/C electrocatalysts. TEM images show that the PtPb nanoparticles distribute uniformly on the carbon support, and are about 4–5 nm in size. The Pt_mPb₁/C bimetallic catalysts show superior activities toward methanol electrooxidation reaction (MOR) than the Pt/C in alkaline media. Both CO stripping measurements and density functional theory studies reveal that CO adsorption decreased significantly on the Pt_mPb₁/C bimetallic catalysts compared with on pure Pt, which may offer an explanation for the enhanced MOR activity of the Pt_mPb₁/C bimetallic catalysts.     

Optimized Backflushing Process for Fibrous Media in Engine Oil Filtration and Enhancement by Ultrasound

Filter media that are made of metal fiber fleece have been qualified as a very suitable method to clean engine oils from fine particles in large diesel application. However, regeneration by backflushing of these densely packed depth filtration media is a great challenge. In experimental studies, the principles of successful hydrodynamic backflushing could be identified. Furthermore, the auxiliary effects of medium‐ and high‐power ultrasound on this process were investigated and could be qualified. Ideal process parameters for the general aim of freeing filter media from clogging particle fractions whilst using minimized amounts of flushing medium can be derived. This generates input parameters for an optimized apparatus design in real‐scale application.