Fixed-order H∞ compensator design

A method is presented for the construction of fixed-order compensators to provide H_∞ norm constraint for linear control systems with exogenous disturbances. The method is based on the celebrated bounded-real lemma that predicates the H_∞ norm constraint via a Riccati inequality. The synthesis of fixed-order controllers whose dimensions are less than the order of a given plant, is demonstrated by a set of sufficient conditions along with a numerical algorithm.     

Sheldon H. White (1928-2005).

Sheldon "Shep" Harold White, one of developmental psychology's most distinguished scholars, died on March 17, 2005, at the age of 76. He is perhaps best remembered for his sharp intellect, generous spirit, good humor, and warm compassion. Shep's principal work lay in three intermeshed areas: children's learning and cognitive development, social programs and policies, and the history of developmental psychology. Shep White is sorely missed by his family and friends, and countless children have unknowingly benefited from his research, scholarship, and contributions to public policy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the determination of boundaries to manipulator workspaces

The accumulation of two independent, broadly applicable formulations for determining the boundary to manipulator workspaces, presented elsewhere, are compared in this paper. Insights gained from one method are used to explain behavior exhibited in the other. Results are also compared and validated. A numerical formulation based on continuation methods is used to map curves that are on the boundary of a manipulator workspace. Analytical criteria based on row rank deficiency criteria of the manipulator's analytical Jacobian are used to map a family of one-dimensional solution curves on the boundary. The other formulation, based on a similar rank-deficiency criteria, yields analytic boundaries parametrized in terms of surface patches on the boundary. Results concerning the applicability of the numerical method to open- and closed-loop systems are compared with those limited to the open-loop for the analytical method. Conclusions regarding the behavior of the manipulator on geometric entities characterized by singular curves, higher-order bifurcation points, and surfaces inside the workspace are drawn. Applicability of both methods and their limitations are also addressed.     

Top-down logic design with pass-transistor cells and efficientsynthesiser

A pass-transistor based cell library containing only two types of cells is designed and a corresponding logic/circuit synthesiser developed for logic mapping of any combinational circuit. The proposed design has better performance than the recently proposed lean integration with pass transistors (LEAP) cell library. Furthermore, the modified LEAP cell library can be easily migrated to a new process technology due to the smaller number of cells     

Novel technique for SiO2 formed by liquid-phasedeposition for low-temperature processed polysilicon TFT

A technique for SiO₂ formation by liquid-phase deposition (LPD) at nearly room temperature for low-temperature processed (LTP) polysilicon thin-film transistor (poly-Si TFT) was developed. LPD SiO₂ film with a lower P-etch rate shows a dense structure. LPD SiO₂ also exhibits good electrical characteristics. LTP poly-Si thin-film transistors (TFTs) with LPD SiO ₂ as the gate insulator have been fabricated and investigated. Their characteristics indicate performance adequate for their use as pixel transistors in liquid crystal displays (LCDs)     

Efficacy of surgical treatment in traumatic central cord syndrome

BACKGROUND: Controversy surrounds the treatment of traumatic central cord syndrome (TCCS), as there are strong advocates for nonsurgical treatment for most patients. However, conservative treatment has been shown to yield a longer period of discomfort from pain and weakness in certain cases. METHODS: In a retrospective review of 114 patients presenting with acute or chronic TCCS from 1988-94, four different age groups were separately observed under different treatments. Motor and sensory recovery were assessed. RESULTS: Better results were achieved in younger patients, with or without radiographic abnormalities, and in patients with clinically correlated encroaching cord lesions who received early surgical decompression. CONCLUSIONS: Surgical intervention for TCCS must be addressed with careful clinical and radiographic survey. Removal of offending lesions in the subacute period results in significant motor and sensory improvement in short-term and long-term follow-up.     

Applying real options in investment decisions relating to environmental pollution

This study focuses on how to assess the optimal environmental investment decisions under economic and ecological uncertainty, and establishes the continuous time model using the real option approach to optimize environmental pollution policy. Unlike traditional cost benefit analysis, this work extends the model of [Pindyck, R.S., 2002. Optimal timing problems in environmental economics. Journal of Economic Dynamics and Control 26(9–10), 1677–1697], and attempts to identify the storage threshold of pollution stocks and the optimal timing for implementing environmental pollution decisions.     

Programmable group-delay module using binary polarization switching

We demonstrate the first programmable group-delay module based on polarization switching. With a unique binary tuning mechanism, the device can generate any differential group delay value from -45 to +45 ps with a resolution of 1.40 ps, or any true-time-delay value from 0 to 45 ps with a resolution of 0.7 ps. The delay varying speeds for both applications are under 1 ms and can be as fast as 0.1 ms. We evaluate both the dynamic and static performances of the device while paying special attention to its dynamic figures of merit for polarization-mode dispersion emulation and compensation applications. Our experiment shows that the device exhibits a negligible transient-effect induced power penalty (<0.2 dB) in a 10-Gb/s nonreturn-to-zero system.     

Effects of Inclined Angle and Plate Spacing on the Degree of Separation in Batch-Type Flat-Plate Thermal Diffusion Columns

Effects of inclined angle and plate spacing on the degree of separation in batch-type flat-plate thermal diffusion columns, with operating expense and fixed charge kept unchanged, are discussed. It was found that the degree ofseparation increases when the inclined angle increases or when the platespacing decreases. However, decreasing the plate spacing will lead to decreasingthe amount of solution to be treated in the column, while increasing the inclined angle will enlarge the operating time for reaching the steady state.