Higher accuracy output feedback sliding mode control of sampled-data systems

(c) 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.This is the author version of a work accepted for publication in IEEE Transactions on Automatic Control. The definitive version is available via the publisher at 10.1109/TAC.2015.2505303The problem of output feedback sliding mode control for sampled-data systems in the presence of external disturbances is considered. The proposed output feedback control strategy helps obtain a quasi sliding mode with an O(T3) boundary layer, where T is the sampling period. This outperforms the O(T2) result induced by the one-step delayed disturbance approximation method. The proposed scheme is applicable to linear systems which are relative degree one and minimum phase. An example is given to illustrate the efficacy of the new method

Evaluation of preferences of women and healthcare professionals in Singapore for implementation of noninvasive prenatal testing for Down syndrome

INTRODUCTION: Invasive prenatal diagnosis (IPD) has long been used to prenatally diagnose Down syndrome (DS), but is associated with a small risk of miscarriage. Meanwhile, noninvasive prenatal testing (NIPT) is a highly sensitive screening test using cell-free DNA in maternal blood for detection of DS that removes the risk of miscarriage, but confers a small risk of false-positive and false-negative results. Their implementations into clinical practice require an understanding of stakeholder preferences. METHODS: A total of 69 health professionals (HPs) and 301 women took part in a discrete choice experiment (DCE) in which preferences for four prenatal test attributes (accuracy, time of results, risk of miscarriage and amount of information provided) were assessed, and conditional logit regression was used to analyse data. Data on demographics and ranked preferences for test attributes were collected, and a direct choice between NIPT, IPD or neither test was given. RESULTS: Women showed a preference for test safety, whereas HPs prioritised test accuracy above all other attributes. When offered a direct choice between NIPT, IPD or neither test, women aged over 35 years, those with previous miscarriage or who knew a child with DS were more likely to choose NIPT than IPD. Chinese women preferred NIPT whereas Indian women preferred IPD. CONCLUSION: Our data highlight the need for patient-specific counselling, taking into account previous experiences and cultural factors. Since women and HPs prioritise different test attributes, it is essential that HPs recognise these differences in order to provide non-biased counselling

Robust Facial Alignment for Face Recognition

© 2017, Springer International Publishing AG. This paper proposes a robust real-time face recognition system that utilizes regression tree based method to locate the facial feature points. The proposed system finds the face region which is suitable to perform the recognition task by geometrically analyses of the facial expression of the target face image. In real-world facial recognition systems, the face is often cropped based on the face detection techniques. The misalignment is inevitably occurred due to facial pose, noise, occlusion, and so on. However misalignment affects the recognition rate due to sensitive nature of the face classifier. The performance of the proposed approach is evaluated with four benchmark databases. The experiment results show the robustness of the proposed approach with significant improvement in the facial recognition system on the various size and resolution of given face images

A review of Lassa fever outbreaks in Nigeria From 1969 to 2017: Epidemiologic profile, determinants and public health response

Introduction: Lassa fever outbreaks have occurred in Nigeria since the 1969 till date. This is in spite of the fact that the reservoir and modes of transmission have been known for all these years. This review aimed at describing the epidemiology and determinants of the Lassa fever outbreaks in Nigeria from 1969 to 2017 and the public health response to these outbreaks.Method: The guidelines for the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) were used to conduct the review between May 2017 and January, 2018. We searched PubMed, Science direct, WHO library databases and Google Scholar for articles published from 1970 till January 2018. Other relevant websites such as those of the World Health Organization, Nigeria Centers for Disease Control and Prevention were searched for Lassa fever outbreak reports.Results: Twenty-six articles and reports were included in the final review. These described twenty-one outbreaks involving 5442 suspect cases, 768 confirmed cases and 631 deaths from suspected or confirmed Lassa fever. Thirty-two states and the Federal Capital Territory have ever recorded outbreaks of Lassa fever. Lassa fever cases now occur in various states in Nigeria all year round with dry season peaks. Nosocomial transmission has remained a consistent determinant. Public health responses have changed over time starting from predominantly case management in initial outbreaks to a centrally coordinated response supporting states and institutions over the years.Conclusion; Lassa fever outbreaks have increased in frequency and geographic spread with case fatality ratio remaining unacceptably high. The same determinants have persisted with nosocomial transmission a consistent factor. Public health response has consistently improved with the last two years showing the most coordinated response. We recommend that the definition of Lassa fever in the Nigerian Integrated Disease Surveillance and Notification System (IDSR) be revised to reflect the current reality to ensure better Lassa fever control.Key words: Lassa fever, Outbreak, Viral haemorrhagic fevers, Nigeria

Analysis and design of irregular tall buildings in Hong Kong by a strength-based design approach

no. SECM/13/25Conference Theme: Capacity Building for DevelopmentThe development of design principles for tall buildings for any level of seismic hazard is much in need because the current codes of practice worldwide still do not fully provide the required guidance. The availability of design experience and guidance for low-to-moderate seismicity regions is especially scant. As buildings become taller, wind effects increase and earthquake effects decrease. Hong Kong, situated in a region of high typhoon and low-to-moderate seismicity, with an abundance of tall buildings, may offer a unique experience in the design of tall buildings for...postprin

Aerobic Exercise and Yoga Improve NeuroCognitive Function in Women with Early Psychosis

Impairments of attention and memory are evident in early psychosis, and are associated with functional disability. In a group of stable, medicated women patients, we aimed to determine whether participating in aerobic exercise or yoga improved cognitive impairments and clinical symptoms. A total of 140 female patients were recruited, and 124 received the allocated intervention in a randomized controlled study of 12 weeks of yoga or aerobic exercise compared with a wait-list group. The primary outcomes were cognitive functions including memory and attention. Secondary outcome measures were the severity of psychotic and depressive symptoms, and hippocampal volume. Data from 124 patients were included in the final analysis based on the intention-to-treat principle. Both yoga and aerobic exercise groups demonstrated significant improvements in working memory (P<0.01) with moderate to large effect sizes compared to the wait-list control group. The yoga group showed additional benefits in verbal acquisition (P<0.01) and attention (P=0.01). Both types of exercise improved overall and depressive symptoms (all P≤0.01) after 12 weeks. Small increases in hippocampal volume were observed in the aerobic exercise group compared with wait-list (P=0.01). Both types of exercise improved working memory in early psychosis patients, with yoga having a larger effect on verbal acquisition and attention than aerobic exercise. The application of yoga and aerobic exercise as adjunctive treatments for early psychosis merits serious consideration. This study was supported by the Small Research Funding of the University of Hong Kong (201007176229), and RGC funding (C00240 / 762412) by the Authority of Research, Hong Kong.published_or_final_versio

Design principles for riboswitch function

Scientific and technological advances that enable the tuning of integrated regulatory components to match network and system requirements are critical to reliably control the function of biological systems. RNA provides a promising building block for the construction of tunable regulatory components based on its rich regulatory capacity and our current understanding of the sequence–function relationship. One prominent example of RNA-based regulatory components is riboswitches, genetic elements that mediate ligand control of gene expression through diverse regulatory mechanisms. While characterization of natural and synthetic riboswitches has revealed that riboswitch function can be modulated through sequence alteration, no quantitative frameworks exist to investigate or guide riboswitch tuning. Here, we combined mathematical modeling and experimental approaches to investigate the relationship between riboswitch function and performance. Model results demonstrated that the competition between reversible and irreversible rate constants dictates performance for different regulatory mechanisms. We also found that practical system restrictions, such as an upper limit on ligand concentration, can significantly alter the requirements for riboswitch performance, necessitating alternative tuning strategies. Previous experimental data for natural and synthetic riboswitches as well as experiments conducted in this work support model predictions. From our results, we developed a set of general design principles for synthetic riboswitches. Our results also provide a foundation from which to investigate how natural riboswitches are tuned to meet systems-level regulatory demands

A robust real-time facial alignment system with facial landmarks detection and rectification for multimedia applications

© 2020, Springer Science+Business Media, LLC, part of Springer Nature. Face detection often plays the first step in various visual applications. Large variants of facial deformations due to head movements and facial expression make it difficult to identify appropriate face region. In this paper, a robust real-time face alignment system, including facial landmarks detection and face rectification, is proposed. A facial landmarks detection model based on regression tree is utilized in the proposed system. In face rectification framework, 2-D geometrical analysis based on pitch, yaw and roll movements is designed to solve the misalignment problem in face detection. The experiments on the two datasets verify the performance significantly improved by the proposed method in the facial recognition task and outperform than those obtained by other alignment methods. Furthermore, the proposed method can achieve robust recognition results even if the amount of training images is not large

Transmutations and spectral parameter power series in eigenvalue problems

We give an overview of recent developments in Sturm-Liouville theory concerning operators of transmutation (transformation) and spectral parameter power series (SPPS). The possibility to write down the dispersion (characteristic) equations corresponding to a variety of spectral problems related to Sturm-Liouville equations in an analytic form is an attractive feature of the SPPS method. It is based on a computation of certain systems of recursive integrals. Considered as families of functions these systems are complete in the $L_{2}$-space and result to be the images of the nonnegative integer powers of the independent variable under the action of a corresponding transmutation operator. This recently revealed property of the Delsarte transmutations opens the way to apply the transmutation operator even when its integral kernel is unknown and gives the possibility to obtain further interesting properties concerning the Darboux transformed Schr\"{o}dinger operators. We introduce the systems of recursive integrals and the SPPS approach, explain some of its applications to spectral problems with numerical illustrations, give the definition and basic properties of transmutation operators, introduce a parametrized family of transmutation operators, study their mapping properties and construct the transmutation operators for Darboux transformed Schr\"{o}dinger operators.Comment: 30 pages, 4 figures. arXiv admin note: text overlap with arXiv:1111.444