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

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

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 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. © 2005 IEEE.published_or_final_versio

Prenatal Diagnosis of Pulmonary Sequestration by Ultrasound and Magnetic Resonance Imaging

A 36-year-old multigravida, G2P1, underwent routine ultrasound scan at 22+1 weeks of gestation, which revealed a single normally growing fetus with left intrathoracic mass and left displacement of the cardiac apex. The left intrathoracic wedge-shaped hyperechogenic mass, measuring 32 × 25 mm in size, was situated at the lower portion of the left lung. A combination of color and power Doppler ultrasound allowed visualization of a vessel arising from the descending aorta, which supplied the mass. The diagnosis of extralobar pulmonary sequestration was made. Magnetic resonance imaging (MRI) was also performed and revealed a well-defined mass with homogeneous high-signal intensity when compared with normal lung tissue in the left upper lung field, which was compatible with pulmonary sequestration. The pulmonary mass was followed up by color and power Doppler every 2 weeks. The peak velocity of 11.85 cm/sec and the diameter of the feeding artery of 1.19 mm gradually decreased and disappeared 8 weeks later. The intrathoracic mass disappeared 10 weeks later at 32+1 gestational weeks. Repeat MRI also revealed spontaneous regression of the mass in favor of resorption of sequestration. The fetus was delivered at 38+1 gestational weeks. A male newborn weighing 2,520 g was spontaneously delivered with an Apgar score of 8 at 1 minute and 9 at 5 minutes. In our patient, it is suggested that progressive decreases in the peak velocity of the feeding vessel heralded the spontaneous regression of pulmonary sequestration not associated with hydrops/hydrothorax

Manipulation of magnetic nanoparticle retention and hemodynamic consequences in microcirculation: assessment by laser speckle imaging

Magnetic nanoparticles (MNPs) have been proposed for targeted or embolization therapeutics. How MNP retention occurs in circulation may critically determine local hemodynamics, tissue distribution of MNPs, and the therapeutic effects. We attempted to establish a microcirculation model to study the magnetic capture of MNPs in small vessels and to determine the factors affecting MNP retention. Two-dimensional hemodynamic changes in response to magnet-induced MNP retention in the microvessels of the cremaster muscle in vivo were observed in a real-time manner using a laser speckle imaging technique. Changes in tissue perfusion of the cremaster muscle appeared to be closely correlated with the location of the magnet placement underneath the muscle in response to intra-arterial administration of dextran-coated MNPs. Magnet-related retention was observed along the edge of the magnet, as corroborated by the results of histology analysis and microcomputed tomography. In these preparations, tissue iron content almost doubled, as revealed by inductively coupled plasma optical emission spectroscopy. In addition, MNP retention was associated with reduced downstream flow in a dose-dependent manner. Dissipation of MNPs (5 mg/kg) occurred shortly after removal of the magnet, which was associated with significant recovery of tissue flow. However, MNP dissipation did not easily occur after administration of a higher MNP dose (10 mg/kg) or prolonged exposure to the magnetic field. An ultrasound after removal of the magnet may induce the partial dispersion of MNPs and thus partially improve hemodynamics. In conclusion, our results revealed the important correlation of local MNP retention and hemodynamic changes in microcirculation, which can be crucial in the application of MNPs for effective targeted therapeutics

Archaeobotanical evidence of plant cultivation from the Sanbaopi site in south-western Taiwan during the Late Neolithic and Metal Age

Despite decades of lively debate about Taiwan’s role in the spread of early agriculture, crops and cultivation practices to the Indo-Pacific region, there is little archaeobotanical data from the island. Here we present the first directly dated and systematically analysed macrobotanical records from Taiwan obtained by flotation at the archaeological site Sanbaopi 5 (23°07′03′′N, 120°15′32′′E), representing the Dahu (1400 BCE–100 CE) and Niaosong (100–1400 CE) culture periods. The results suggest that Middle Dahu (900–100 BCE) communities in the study area practiced rainfed crop cultivation with mainly foxtail (Setaria italica) and broomcorn (Panicum miliaceum) millet and rice (Oryza sativa). Pulses (Vigna angularis, Glycine soja/max) were also part of the subsistence of local farmers and used as supplementary food and/or green manure. The archaeobotanical record together with archaeological site data for prehistoric China substantiates evidence that the Dahu culture originates in the Lower Yellow River region and migrated to Taiwan along the East China Sea coast. The emergence of the Dahu culture coincided with the spread of mixed millet-rice farming to the Korean Peninsula and Japan and was possibly related to enhanced economic and political expansion of the Shang and Western Zhou dynasties and the long-term weakening of summer monsoon precipitation. Pigeon pea (Cajanus cajan) and mung bean (V. radiata var. radiata) assemblages from the sixth century CE Niaosong period highlight the influx of goods, crops, knowledge and people from South and Southeast Asia via southern routes in the context of enhanced exchange across the South China Sea region

Two decades of change in cultural values and economic development in eight East Asian and Pacific Island nations

In a 1982 publication, Ng et al. surveyed the cultural values of select East Asian and Pacific Island nations. In 2002, this study repeated their work, using the same sampling frame, questionnaire, and collaborators, where possible. The authors also reclassified the 1982 and 2002 survey results using Schwartz's cultural-level value dimensions. Submission versus Dionysian values that differentiated the nations in 1982 continued to do so in 2002. Furthermore, nations that endorsed Mastery (and rejected Harmony) in 1982 experienced greater subsequent economic growth than did the other countries. Moreover, economic development in 1982 predicted ensuing changes in Submission versus Dionysian and Hierarchy versus Egalitarianism values. Richer nations tended to endorse Dionysian, Autonomy, and Egalitarianism, whereas poorer nations tended toward Submission, Embeddedness, and Hierarchy values. Overall, the results support both economic and cultural determinism and imply two opposing directions of cultural change

Robust H∞ finite-horizon filtering with randomly occurred nonlinearities and quantization effects

The official published version of this article can be found at the link below.In this paper, the robust H∞ finite-horizon filtering problem is investigated for discrete time-varying stochastic systems with polytopic uncertainties, randomly occurred nonlinearities as well as quantization effects. The randomly occurred nonlinearity, which describes the phenomena of a nonlinear disturbance appearing in a random way, is modeled by a Bernoulli distributed white sequence with a known conditional probability. A new robust H∞ filtering technique is developed for the addressed Itô-type discrete time-varying stochastic systems. Such a technique relies on the forward solution to a set of recursive linear matrix inequalities and is therefore suitable for on-line computation. It is worth mentioning that, in the filtering process, the information of both the current measurement and the previous state estimate is employed to estimate the current state. Finally, a simulation example is exploited to show the effectiveness of the method proposed in this paper.This work was supported in part by the Engineering and Physical Sciences Research Council (EPSRC) of the UK under Grant GR/S27658/01, the Royal Society of the UK, the National 973 Program of China under Grant 2009CB320600, the National Natural Science Foundation of China under Grant 60974030, the Shanghai Natural Science Foundation of China under Grant 10ZR1421200, and the Alexander von Humboldt Foundation of Germany