Mixed H2/H∞ filtering for uncertain systems with regional pole assignment

Copyright [2005] IEEE. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.The mixed H2/H∞ filtering problem for uncertain linear continuous-time systems with regional pole assignment is considered. The purpose of the problem is to design an uncertainty-independent filter such that, for all admissible parameter uncertainties, the following filtering requirements are simultaneously satisfied: 1) the filtering process is asymptotically stable; 2) the poles of the filtering matrix are located inside a prescribed region that compasses the vertical strips, horizontal strips, disks, or conic sectors; 3) both the H2 norm and the H∞ norm on the respective transfer functions are not more than the specified upper bound constraints. We establish a general framework to solve the addressed multiobjective filtering problem completely. In particular, we derive necessary and sufficient conditions for the solvability of the problem in terms of a set of feasible linear matrix inequalities (LMIs). An illustrative example is given to illustrate the design procedures and performances of the proposed method

Random Shapley Forests: Cooperative Game Based Random Forests with Consistency

The original random forests algorithm has been widely used and has achieved excellent performance for the classification and regression tasks. However, the research on the theory of random forests lags far behind its applications. In this paper, to narrow the gap between the applications and theory of random forests, we propose a new random forests algorithm, called random Shapley forests (RSFs), based on the Shapley value. The Shapley value is one of the well-known solutions in the cooperative game, which can fairly assess the power of each player in a game. In the construction of RSFs, RSFs uses the Shapley value to evaluate the importance of each feature at each tree node by computing the dependency among the possible feature coalitions. In particular, inspired by the existing consistency theory, we have proved the consistency of the proposed random forests algorithm. Moreover, to verify the effectiveness of the proposed algorithm, experiments on eight UCI benchmark datasets and four real-world datasets have been conducted. The results show that RSFs perform better than or at least comparable with the existing consistent random forests, the original random forests and a classic classifier, support vector machines

SUMO Modification Stabilizes Enterovirus 71 Polymerase 3D To Facilitate Viral Replication.

Accumulating evidence suggests that viruses hijack cellular proteins to circumvent the host immune system. Ubiquitination and SUMOylation are extensively studied posttranslational modifications (PTMs) that play critical roles in diverse biological processes. Cross talk between ubiquitination and SUMOylation of both host and viral proteins has been reported to result in distinct functional consequences. Enterovirus 71 (EV71), an RNA virus belonging to the family Picornaviridae, is a common cause of hand, foot, and mouth disease. Little is known concerning how host PTM systems interact with enteroviruses. Here, we demonstrate that the 3D protein, an RNA-dependent RNA polymerase (RdRp) of EV71, is modified by small ubiquitin-like modifier 1 (SUMO-1) both during infection and in vitro Residues K159 and L150/D151/L152 were responsible for 3D SUMOylation as determined by bioinformatics prediction combined with site-directed mutagenesis. Also, primer-dependent polymerase assays indicated that mutation of SUMOylation sites impaired 3D polymerase activity and virus replication. Moreover, 3D is ubiquitinated in a SUMO-dependent manner, and SUMOylation is crucial for 3D stability, which may be due to the interplay between the two PTMs. Importantly, increasing the level of SUMO-1 in EV71-infected cells augmented the SUMOylation and ubiquitination levels of 3D, leading to enhanced replication of EV71. These results together suggested that SUMO and ubiquitin cooperatively regulated EV71 infection, either by SUMO-ubiquitin hybrid chains or by ubiquitin conjugating to the exposed lysine residue through SUMOylation. Our study provides new insight into how a virus utilizes cellular pathways to facilitate its replication. IMPORTANCE: Infection with enterovirus 71 (EV71) often causes neurological diseases in children, and EV71 is responsible for the majority of fatalities. Based on a better understanding of interplay between virus and host cell, antiviral drugs against enteroviruses may be developed. As a dynamic cellular process of posttranslational modification, SUMOylation regulates global cellular protein localization, interaction, stability, and enzymatic activity. However, little is known concerning how SUMOylation directly influences virus replication by targeting viral polymerase. Here, we found that EV71 polymerase 3D was SUMOylated during EV71 infection and in vitro Moreover, the SUMOylation sites were determined, and in vitro polymerase assays indicated that mutations at SUMOylation sites could impair polymerase synthesis. Importantly, 3D is ubiquitinated in a SUMOylation-dependent manner that enhances the stability of the viral polymerase. Our findings indicate that the two modifications likely cooperatively enhance virus replication. Our study may offer a new therapeutic strategy against virus replication

Assess the effect of different degrees of urbanization on land surface temperature using remote sensing images

AbstractUrbanization is a human-dominated process and has greatly impacted biodiversity, ecosystem processes, and regional climate. In this study we assess the effect of different degrees of urbanization on land surface temperature using remote sensing images. Landsat TM images were used for land surface temperature retrieval using the algorithm proposed by Artis and Carnahan. ALOS multispectral images were used for landcover classification using classification trees in three study areas, namely Xicheng district(A), Haidian district(B), Shijingshan district(C), of different degrees of urbanization in Beijing. Landcover-specific surface temperatures were estimated through an inversion alorithm. At the different degrees of urbanization, reducing the within-pixel coverage ratio of vegetations will result in an land surface temperature rise. Quantitative assessment of the relationship between different degrees of urbanization and land surface temperature was simulated by an urbanization index which integrates the coverage ratio of built-up landcover type and the cell-average NDVI. Urbanization indices of the Xicheng district, Haidian district, Shijingshan district were calculated to be 0.91, 0.72, and, 0.55 respectively. Such results are consistent with the trend of evaluation using quantitative estimation land surface temperature

The influence law of process parammeters on end concavity of hexahedral blank cross wedge rolling (CWR)

In order to expand the range of the cross wedge rolling (CWR) product, realize CWR of hexahedral blank. In this paper, the three-dimensional Finite element model (FEM) of hexahedral blank CWR is established by DEFORM finite element software. The influence of forming angle, spreading angle and section shrinkage on the length of concavity is analyzed, compared with the round billet rolling results under the same parameters, the concavity length of the hexahedral blank is slightly larger than that of round billet, and the influence of process parameters on the concavity is basically the same. The research results provide theoretical guidance for the rational determination of process parameters for CWR of hexahedral blank

The influence law of process parammeters on end concavity of hexahedral blank cross wedge rolling (CWR)

In order to expand the range of the cross wedge rolling (CWR) product, realize CWR of hexahedral blank. In this paper, the three-dimensional Finite element model (FEM) of hexahedral blank CWR is established by DEFORM finite element software. The influence of forming angle, spreading angle and section shrinkage on the length of concavity is analyzed, compared with the round billet rolling results under the same parameters, the concavity length of the hexahedral blank is slightly larger than that of round billet, and the influence of process parameters on the concavity is basically the same. The research results provide theoretical guidance for the rational determination of process parameters for CWR of hexahedral blank