Finite-region stability of 2-D singular Roesser systems with directional delays

In this paper, the problem of finite-region stability is studied for a class of two-dimensional (2-D) singular systems described by using the Roesser model with directional delays. Based on the regularity, we first decompose the underlying singular 2-D systems into fast and slow subsystems corresponding to dynamic and algebraic parts. Then, with the Lyapunov-like 2-D functional method, we construct a weighted 2-D functional candidate and utilize zero-type free matrix equations to derive delay-dependent stability conditions in terms of linear matrix inequalities (LMIs). More specifically, the derived conditions ensure that all state trajectories of the system do not exceed a prescribed threshold over a pre-specified finite region of time for any initial state sequences when energy-norms of dynamic parts do not exceed given bounds

A direct evidence of fatigue damage growth inside silicon MEMS structures obtained with EBIC technique

Electron beam induced current (EBIC) is a semiconductor analysis technique performed in a scanning electron microscope (SEM) or scanning transmission electron microscope (STEM). It is able to sense defects beneath the surface even invisible by SEM. This paper presents the results of a trial to observe the defect growth inside silicon MEMS structures under fatigue loading by applying EBIC technique. The tests were performed on two specimens fabricated from an n-type single crystal silicon wafer. While the test region of the specimens was repeatedly subjected to compressive stress, EBIC images were obtained to visualize damage evolution which presented by the growth of the dark region on EBIC images. It was proved that the damage is not due to the growth of oxidation layer on the surface of the specimens but due to the growth of intrinsic defects of silicon crystal. The results would be evidences to elucidate that the fatigue damages grow inside silicon MEMS structures but not in oxidation layer

Creating Fatigue Curve for Steel Machine Elements Using Fatigue Test Method with Gradually Increasing Stress Amplitude

In order to create a fatigue curve, the traditional fatigue test method is applied to specimens using a cyclic stress with constant amplitude. However, this method has disadvantages such as the experimental results could not be used because of specimens broken before reaching the expected stress amplitude, or the tests may be stopped before specimen broken because of limitation of time. To overcome this hurdle of the traditional method, a new experimental method using cyclic stress with gradually increasing amplitude was proposed to build the fatigue curve for steel machine elements

Trends in, projections of, and inequalities in reproductive, maternal, newborn and child health service coverage in Vietnam 2000-2030 : a Bayesian analysis at national and sub-national levels

Background: To assess the reproductive, maternal, newborn and child health (RMNCH) service coverage in Vietnam with trends in 2000−2014, projections and probability of achieving targets in 2030 at national and sub-national levels; and to analyze the socioeconomic, regional and urban-rural inequalities in RMNCH service indicators. Methods: We used national population-based datasets of 44,624 households in Vietnam from 2000 to 2014. We applied Bayesian regression models to estimate the trends in and projections of RMNCH indicators and the probabilities of achieving the 2030 targets. Using the relative index, slope index, and concentration index of inequality, we examined the patterns and trends in RMNCH coverage inequality. Findings: We projected that 9 out of 17 health service indicators (53%) would likely achieve the 2030 targets at the national level, including at least one and four ANC visits, BCG immunization, access to improved water and adequate sanitation, institutional delivery, skilled birth attendance, care-seeking for pneumonia, and ARI treatment. We observed very low coverages and zero chance of achieving the 2030 targets at national and sub-national levels in early initiation and exclusive breastfeeding, family planning needs satisfied, and oral rehydration therapy. The most deprived households living in rural areas and the Northwest, Northeast, North Central, Central Highlands, and Mekong River Delta regions would not reach the 80% immunization coverage of DPT3, Polio3, Measles and full immunization. We found socioeconomic, regional, and urban-rural inequalities in all RMNCH indicators in 2014 and no change in inequalities over 15 years in the lowest-coverage indicators. Interpretation: Vietnam has made substantial progress toward UHC. By improving the government's health system reform efforts, re-allocating resources focusing on people in the most impoverished rural regions, and restructuring and enhancing current health programs, Vietnam can achieve the UHC targets and other health-related SDGs. Funding: The authors did not receive any funds for conducting this study. © 2021 The Author(s

Etiology and epidemiology of diarrhea in children in Hanoi, Vietnam

SummaryObjectivesThis paper provides a preliminary picture of diarrhea with regards to etiology, clinical symptoms, and some related epidemiologic factors in children less than five years of age living in Hanoi, Vietnam.MethodsThe study population included 587 children with diarrhea and 249 age-matched healthy controls. The identification of pathogens was carried out by the conventional methods in combination with ELISA, immunoseparation, and PCR. The antibiotic susceptibility was determined by MIC following the NCCLS recommendations.ResultsOf those with diarrhea, 40.9% were less than one year old and 71.0% were less than two years old. A potential pathogen was identified in 67.3% of children with diarrhea. They were group A rotavirus, diarrheagenic Escherichia coli, Shigella spp, and enterotoxigenic Bacteroides fragilis, with prevalences of 46.7%, 22.5%, 4.7%, and 7.3%, respectively. No Salmonella spp or Vibrio cholerae were isolated. Rotavirus and diarrheagenic E. coli were predominant in children less than two years of age, while Shigella spp, and enterotoxigenic B. fragilis were mostly seen in the older children. Diarrheagenic E. coli and Shigella spp showed high prevalence of resistance to ampicillin, chloramphenicol, and to trimethoprim/sulfamethoxazole. Children attending the hospitals had fever (43.6%), vomiting (53.8%), and dehydration (82.6%). Watery stool was predominant with a prevalence of 66.4%, followed by mucous stool (21.0%). The mean episodes of stools per day was seven, ranging from two to 23 episodes. Before attending hospitals, 162/587 (27.6%) children had been given antibiotics. Overall, more children got diarrhea in (i) poor families; (ii) families where piped water and a latrine were lacking; (iii) families where mothers washed their hands less often before feeding the children; (iv) families where mothers had a low level of education; (v) families where information on health and sanitation less often reached their households.ConclusionsGroup A rotavirus, diarrheagenic Escherichia coli, Shigella spp, and enterotoxigenic Bacteroides fragilis play an important role in causing diarrhea in children in Hanoi, Vietnam. Epidemiological factors such as lack of fresh water supply, unhygienic septic tank, low family income, lack of health information, and low educational level of parents could contribute to the morbidity of diarrhea in children

Asymptotic periodic solutions of differential equations with infinite delay

In this paper, by using the spectral theory of functions and properties of evolution semigroups, we establish conditions on the existence, and uniqueness of asymptotic 1-periodic solutions to a class of abstract differential equations with infinite delay of the form \begin{equation*} \frac{d u(t)}{d t}=A u(t)+L(u_t)+f(t) \end{equation*} where $A$ is the generator of a strongly continuous semigroup of linear operators, $L$ is a bounded linear operator from a phase space $\mathscr{B}$ to a Banach space $X$, $u_t$ is an element of $\mathscr{B}$ which is defined as $u_t(\theta)=u(t+\theta)$ for $\theta \leq 0$ and $f$ is asymptotic 1-periodic in the sense that $\lim\limits_{t \rightarrow \infty}(f(t+1)-$ $f(t))=0$. A Lotka-Volterra model with diffusion and infinite delay is considered to illustrate our results.Comment: 13 page

A Status Data Transmitting System for Vessel Monitoring

This paper presents a status data transmitting system suitable for vessel monitoring. The system consists of four main parts, which are a status data module, a frequency synthesizer, a power amplifier and a horn antenna. The status data module packs information of the identification, longitude, latitude and state of the vessel into data frames. FSK/MSK/GMSK schemes were used to modulate the data. The frequency synthesizer was designed with very high stability over temperature and very low frequency tolerance. The power amplifier provides 130 W output power at S band. The impedance bandwidth of the horn antenna can be controlled using the beveling technique

Active disturbance rejection control-based anti-coupling method for conical magnetic bearings

Conical-shape magnetic bearings are currently a potential candidate for various magnetic force-supported applications due to their unique geometric nature reducing the number of required active magnets. However, the bearing structure places control-engineering related problems in view of underactuated and coupling phenomena. The paper proposes an Adaptive Disturbance Rejection Control (ADRC) for solving the above-mentioned problem in the conical magnetic bearing. At first, virtual current controls are identified to decouple the electrical sub-system, then the active disturbance rejection control is employed to eliminate coupling effects owing to rotational motions. Comprehensive simulations are provided to illustrate the control ability

STIRLING ENGINE: FROM DESIGN TO APPLICATION INTO PRACTICE AND EDUCATION

Stirling motor is a type of outside ignition heat motor that can utilize various fuel sources from customary structures (coal, oil, kindling, rice husk, and so forth) to sustainable power sources (sun-oriented energy), climate, squander heat usage, and so forth). The article centers around introducing the fundamental highlights of the improvement history, activity qualities, and plan techniques for certain sorts of Stirling motors, in this way offering useful appropriateness as well as a college preparing for understudies. The understudy studying Thermal Engineering in our nation today.