Fiber bragg grating tuner

US7507891; US7507891 B2; US7507891B2; US7,507,891; US 7,507,891 B2; 7507891; Application No. 11/723,555Author name used in this publication: Kin Tak LauUSVersion of Recor

Necessary and sufficient conditions for stable H∞ stabilizability

In this paper, the stable H∞ control problem is addressed. It is shown that the stable H∞ control problem is reduced to finding a unimodular matrix such that a two block H∞ optimization problem is solvable. And then it can be solved if an unimodular matrix is selected such that a Nehari problem is solvable. In fact, if the unimodular matrix is selected as a constant matrix, then a previous result is obtained.published_or_final_versio

Poles of regular quaternionic functions

This paper studies the singularities of Cullen-regular functions of one quaternionic variable. The quaternionic Laurent series prove to be Cullen-regular. The singularities of Cullen-regular functions are thus classified as removable, essential or poles. The quaternionic analogues of meromorphic complex functions, called semiregular functions, turn out to be quotients of Cullen-regular functions with respect to an appropriate division operation. This allows a detailed study of the poles and their distribution.Comment: 14 page

The role of culture in quality improvement in the intensive care unit: A literature review

Improving the quality of patient care and patient outcomes is a major concern internationally. In a developing health care system, implementing quality improvement is challenging due not only to resource and workforce issues but also cultural factors. Using the method of a focused literature review, this paper discusses the importance of assessing a societal view of culture, social mores and customs, and power relationships in quality improvement activities using the intensive care unit as an exemplar. We conclude that implementing quality improvement strategies in a developing health care system needs to address the broader perspectives of social and cultural systems particularly hierarchical relationships and issues of non-disclosure

Deletion of SIRT1 in perivascular adipose tissue accelerates obesity-induced endothelial dysfunction

Conference Theme: Tomorrow’s medicines: pharmacology, patients and populationsINTRODUCTION: Perivascular adipose tissue (PVAT) exhibits brown adipose features and its dysfunction is implicated in cardiovascular diseases. SIRT1 is key to adipocyte phenotypes and metabolism. AIMS: In the present study, we aim to investigate the role of SIRT1 within PVAT in modulating obesity-evoked endothelial dysfunction. Methods. Wild type (WT) and adipocyte-specific SIRT1 knockout mice (AKO) were fed with standard chow or westernized diet for 12 weeks. Endothelium-dependent relaxation (EDR) in aortic rings with or without PVAT was assessed by wire myograph. DHE staining was …published_or_final_versio

Noncommutative generalizations of theorems of Cohen and Kaplansky

This paper investigates situations where a property of a ring can be tested on a set of "prime right ideals." Generalizing theorems of Cohen and Kaplansky, we show that every right ideal of a ring is finitely generated (resp. principal) iff every "prime right ideal" is finitely generated (resp. principal), where the phrase "prime right ideal" can be interpreted in one of many different ways. We also use our methods to show that other properties can be tested on special sets of right ideals, such as the right artinian property and various homological properties. Applying these methods, we prove the following noncommutative generalization of a result of Kaplansky: a (left and right) noetherian ring is a principal right ideal ring iff all of its maximal right ideals are principal. A counterexample shows that the left noetherian hypothesis cannot be dropped. Finally, we compare our results to earlier generalizations of Cohen's and Kaplansky's theorems in the literature.Comment: 41 pages. To appear in Algebras and Representation Theory. Minor changes were made to the numbering system, in order to remain consistent with the published versio

Factorizations of Elements in Noncommutative Rings: A Survey

We survey results on factorizations of non zero-divisors into atoms (irreducible elements) in noncommutative rings. The point of view in this survey is motivated by the commutative theory of non-unique factorizations. Topics covered include unique factorization up to order and similarity, 2-firs, and modular LCM domains, as well as UFRs and UFDs in the sense of Chatters and Jordan and generalizations thereof. We recall arithmetical invariants for the study of non-unique factorizations, and give transfer results for arithmetical invariants in matrix rings, rings of triangular matrices, and classical maximal orders as well as classical hereditary orders in central simple algebras over global fields.Comment: 50 pages, comments welcom

Research on the Social Causes of Juvenile Crime: Final Report

published_or_final_versionCommissioned by: Fight Crime Committee. Prepared by: The University of Hong Kon

AMoDSim: An Efficient and Modular Simulation Framework for Autonomous Mobility on Demand

Urban transportation of next decade is expected to be disrupted by Autonomous Mobility on Demand (AMoD): AMoD providers will collect ride requests from users and will dispatch a fleet of autonomous vehicles to satisfy requests in the most efficient way. Differently from current ride sharing systems, in which driver behavior has a clear impact on the system, AMoD systems will be exclusively determined by the dispatching logic. As a consequence, a recent interest in the Operations Research and Computer Science communities has focused on this control logic. The new propositions and methodologies are generally evaluated via simulation. Unfortunately, there is no simulation platform that has emerged as reference, with the consequence that each author uses her own custom-made simulator, applicable only in her specific study, with no aim of generalization and without public release. This slows down the progress in the area as researchers cannot build on each other's work and cannot share, reproduce and verify the results. The goal of this paper is to present AMoDSim, an open-source simulation platform aimed to fill this gap and accelerate research in future ride sharing systems

Endothelium-selective activation of AMP-activated protein kinase improves re-endothelialization and vascular function via induction of heme oxygenase-1 in diabetic mice

This journal suppl. entitled: EDHF 2012 - 10th Anniversary MeetingReduced number and impaired function of endothelial progenitor cells (EPCs) exacerbate vascular injury in diabetes. As AMP-activated kinase (AMPK) is a target of several anti-diabetic and cardiovascular drugs, this study investigated whether endothelium-selective activation of AMPK prevents diabetes-induced impairment in endothelial repair and vasoreactivity by impro...postprin