1,255 research outputs found
Robust ÎâControl for a Class of Discrete Time-Delay Stochastic Systems with Randomly Occurring Nonlinearities
Copyright © 2014 Yamin Wang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.In this paper, we consider the robust Îâ control problem for a class of discrete time-delay stochastic systems with randomly occurring nonlinearities. The parameter uncertainties enter all the system matrices; the stochastic disturbances are both state and control dependent, and the randomly occurring nonlinearities obey the sector boundedness conditions. The purpose of the problem addressed is to design a state feedback controller such that, for all admissible uncertainties, nonlinearities, and time delays, the closed-loop system is robustly asymptotically stable in the mean square, and a prescribed Îâ disturbance rejection attenuation level is also guaranteed. By using the Lyapunov stability theory and stochastic analysis tools, a linear matrix inequality (LMI) approach is developed to derive sufficient conditions ensuring the existence of the desired controllers, where the conditions are dependent on the lower and upper bounds of the time-varying delays. The explicit parameterization of the desired controller gains is also given. Finally, a numerical example is exploited to show the usefulness of the results obtained.This work was supported in part by the National Natural Science Foundation of China under Grants 61374010,
61074129, and 61175111, the Natural Science Foundation of Jiangsu Province of China under Grant BK2012682, the Qing Lan Project of Jiangsu Province (2010), the 333 Project of Jiangsu Province (2011), and the Six Talents Peak Project of Jiangsu Province (2012)
The Experience Of Saudi Students Writing Academic English In Sex-Separated Classrooms
This is a qualitative research that investigates the experiences of undergraduate Saudi female and male students majoring in English at Taif University, Saudi Arabia. These students were part of different sections of a course that teaches academic English writing and research in an English as a Foreign Language context. These Saudi female and male students draw on their perceptions of three main points; First, how they experienced the academic English writing course in sex-separated classrooms. Second, how the current sex-separated classrooms influence their learning of English and how if this hypothetically change to mixed-sex classrooms their experiences in learning English might change. Third, this research explores the studentsâ practice of âTranslanguagingâ learning English in general and writing in specific in their sex-separated sections of the academic English writing course. The focus on translanguaging in this research considers it as a break and shift from the traditional standard way English and academic English writing is taught to non-native speakers/ learners of English. This is a phenomenological study that uses feminist standpoint theory as its main theoretical analysis of the phenomena explored. Major findings of the study include clear discrepancy in the way women are taught English and academic English writing compared to men, the feeling of pressure shared between women to master English, the relatively shared excitement about mixed education by women, and that the practice of translanguaging in itself is gendered, since female students experience less flexibility and tolerance in using Arabic in the classroom than men
A new high-sensitive nephelometric method for assaying serum C-reactive protein based on phosphocholine interaction
Background: The measurement of C-reactive protein (CRP) concentrations has been of interest as a classical marker of acute phase response; in addition, it has been of particular interest in cardiovascular risk stratification where high-sensitive measurements are necessary. Since CRP is able to bind phospholipids (mainly phosphocholine) in the presence of calcium ions, we explored the possibilities of developing a high-sensitive affordable nephelometric CRP assay based on diluted soy oil emulsions.
Methods: Serum (or heparinized plasma) was mixed with Intralipid 20% in Tris-calcium buffer (pH 7.5). After 12 min of incubation at 37 degrees C, the CRP-phospholipid complexes were measured by nephelometry (840 nm) using a BN II nephelometer (Siemens). Results (n=97) were compared with those obtained using a typical immunoturbidimetric method (Roche).
Results: Imprecision of the functional nephelometric assay was evaluated using three human serum pools. Within-run coefficients of variation (CVs) for level 1, 2 and 3 were 6.1%, 4.7% and 4.5%, respectively, and between-run CVs were 17.6%, 18.8% and 11.3%, respectively. Good agreement was obtained between the functional nephelometric and the immunoturbidimetric CRP assay in a concentration range from 0.1 mg/L to 50 mg/L (r=0.884). A logit-log calibration curve was made between 0.056 mg/L and 1.785 mg/L. The limit of detection was 0.5 mg/L.
Conclusions: The functional nephelometric CRP assay allowed high-sensitive CRP determinations in serum and plasma. Since the assay is species independent, the described functional CRP assay could be used for veterinary purposes as well
The Incidence Rate, Types, and External Causes of Traumatic Brain Injuries in Parkinsonâs Disease Patients in Nebraska 2008-2014
Background: Parkinsonâs disease (PD) patients are at higher risk of traumatic brain injury (TBI) due to disease characteristics like tremor, bradykinesia, and impaired balance. Most of the studies that have been done in the United States to investigate the incident rate and causes of TBI among PD patients have mainly focused on falls, while none of these studies have thoroughly addressed all causes of TBI among the PD population or have used a population-based database. Our study aims to investigate the incidence rate, types, and external causes of TBI stratified by age of PD diagnosis using a population-based database from Nebraska. The outcomes of this study will provide valuable insights regarding the cause of TBI episodes among the PD population.
Methods: We conducted a retrospective study comprising of patients diagnosed with PD between 2008-2014. A statewide linkage was done between Nebraska PD Registry data and the Nebraska hospital discharge database (HDD). 4037 PD patients were enrolled in the study. PD patients were grouped based on their age of diagnosis into four categories; 30-59 years, 60-69 years, 70-79 years, and â„80 years. The overall incidence rate and age-specific incidence rate of TBI in the Nebraska PD population was calculated. A chi-square test and multivariable logistic regression model was used to determine the age-specific difference of TBI among those with PD. Frequencies were used to describe the subtypes and external causes of TBI among the four age groups of PD patients.
Results: Between 2008 and 2014, 216 (5.35%) PD patients and 43,530 (4.1%) non-PD residents sustained TBI in Nebraska. The age-adjusted incidence rate of TBI was eight times higher in the PD subject than the general population (4,109 per 100,000 vs. 513 per 100,000). Among PD subjects, logistic regression analysis revealed that age of diagnosis and disease duration were significantly associated with TBI, (p=0.0008 and p=0.0079, respectively). Among PD patients with TBI, unspecified head injury was the most frequent type of TBI (68.5%) followed by concussion (27.5%). Falls accounted for 88.9% of TBI incidents among the PD population.
Conclusion: PD patients experienced more TBI events than the general population. After adjusting for age, gender, disease duration, and location of residence, age and disease duration were significantly associated with TBI among the PD population. The analysis also revealed that unspecified head injury and concussion were the most common types of TBI in both PD and the general population. Further analysis showed that falls accounted for the majority of TBI episodes among PD and the general population. Nonetheless, PD patients suffered from a higher rate of falls compared to general population
Existence of random attractors for a class of second order lattice dynamical systems with Brownian motions
Copyright © 2014 Yamin Wang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.For abstract, see attached file.The National Natural Science Foundation of China under Grant nos. 61374010, 61074129, and 61175111, the Natural Science Foundation of Jiangsu Province of China under Grant BK2012682, the Qing
Lan Project of Jiangsu Province (2010), the 333 Project of Jiangsu Province (2011), and the Six Talents Peak Project of Jiangsu Province (DZXX-047)
Reliable H â filtering for stochastic spatialâtemporal systems with sensor saturations and failures
This study is concerned with the reliable Hâ filtering problem for a class of stochastic spatialâtemporal systems
with sensor saturations and failures. Different from the continuous spatialâtemporal systems, the dynamic behaviour of the system under consideration evolves in a discrete rectangular region. The aim of this study is to estimate the system states through the measurements received from a set of sensors located at some specified points. In order to cater for more realistic signal transmission process, the phenomena of sensor saturations and sensor failures are taken into account. By using the vector reorganisation approach, the spatialâtemporal system is first transformed into an equivalent ordinary differential dynamic system. Then, a filter is constructed and a sufficient condition is obtained under which the filtering error dynamics is asymptotically stable in probability and the Hâ performance requirement is met. On the basis of the analysis results, the desired reliable Hâ filter is designed. Finally, an illustrative example is given to show the effectiveness of the proposed filtering scheme.Deanship of Scientific Research (DSR) at King Abdulaziz University in Saudi Arabia under Grant 16-135-35-HiCi, the National Natural Science Foundation of China under Grants 61329301, 61134009 and 61473076, the Shanghai Rising-Star Program of China under Grant 13QA1400100, the Shu Guang project of Shanghai Municipal Education Commission and Shanghai Education Development Foundation under Grant 13SG34, the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, the Fundamental Research Funds for the Central Universities, the DHU Distinguished Young Professor Program, and the Alexander von Humboldt Foundation of German
Evaluation of the Surgical and Pharmacological Treatment of Diabetic Foot Infection: A Retrospective Study
BACKGROUND: Diabetic foot infection is a major cause of patient disabilities and lowers limb amputations, with high treatment costs and hospitalisation requirements.
AIM: Aim of this study was to evaluate surgical wound care plus antibiotic effects in the treatment of mild and moderate diabetic foot infections.
METHODS: This retrospective study involved 60 patients with diabetic foot infections with or without osteomyelitis. The patients were categorised as group 1 mild and group 2 moderate. Both groups were treated using local wound debridement and the systemic administration of antibiotics. Group 1 (16) patients were treated with two regimens of oral antibiotics in two regimens, A (amoxicillin/clavulanate + metronidazole) and B (clindamycin + metronidazole), for 10-14 days. Group 2 (42) patients were treated with oral plus intravenous antibiotics in two regimens, A (ampicillin + cloxacillin + metronidazole) and B (lincomycin + metronidazole), for 6 weeks. The patients followed-up with local wound care specialists for 3 months to evaluate the treatment outcomes (cure, improvement, or failure).
RESULTS: Group 1 had an 80% cure rate under regimen A and a 100% cure rate under regimen B. Group 2 regimen A patients had a 61.5% cure rate and 11.53% improved, while regimen B patients had a 68.75% cure rate and 12.5% improved. Failure in both regimens was 23.8% in 20 patients with osteomyelitis, while 35% were cured and 20% improved during the study period.
CONCLUSION: Local surgical wound care for 3 months with antibiotic regimens for 6 weeks resulted in good response and cure rates, with lower costs and fewer instances of hospitalisation. Intravenous lincomycin and oral metronidazole achieved higher cure responses for moderate diabetic foot infections
Analysis, filtering, and control for Takagi-Sugeno fuzzy models in networked systems
Copyright © 2015 Sunjie Zhang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.The fuzzy logic theory has been proven to be effective in dealing with various nonlinear systems and has a great success in industry applications. Among different kinds of models for fuzzy systems, the so-called Takagi-Sugeno (T-S) fuzzy model has been quite popular due to its convenient and simple dynamic structure as well as its capability of approximating any smooth nonlinear function to any specified accuracy within any compact set. In terms of such a model, the performance analysis and the design of controllers and filters play important roles in the research of fuzzy systems. In this paper, we aim to survey some recent advances on the T-S fuzzy control and filtering problems with various network-induced phenomena. The network-induced phenomena under consideration mainly include communication delays, packet dropouts, signal quantization, and randomly occurring uncertainties (ROUs). With such network-induced phenomena, the developments on T-S fuzzy control and filtering issues are reviewed in detail. In addition, some latest results on this topic are highlighted. In the end, conclusions are drawn and some possible future research directions are pointed out.This work was supported in part by the National Natural Science Foundation of China under Grants 61134009, 61329301, 11301118 and 61174136, the Natural Science Foundation of Jiangsu Province of China under Grant BK20130017, the Fundamental Research Funds for the Central Universities of China under Grant CUSF-DH-D-2013061, the Royal Society of the U.K., and the Alexander von Humboldt Foundation of Germany
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