A stereocontrolled synthesis of an aryl

Prognosis of discrete component with intermittent fault in hybrid systems is challenging since the has only two states (i.e., ON and OFF) no associated physical parameter model can quantify degradation. This article aims to solve prognosis problem under model-based paradigm. First, detection isolation module help find possible faulty components. Based on isolated components, Levy flight biogeography-based optimization proposed identify states, as well appearing disappearing instants. Second,...

This paper deals with bond-graph-based fault detection, isolation, and estimation, which is applied to a nonlinear electromechanical system, in the presence of parametric faults nonparametric faults. The concept extended analytical redundancy relations (EARRs) developed where both multiplicative additive natures can be considered distinguished. integration dependent EARR independent leads more efficient isolation number potential could decreased. For purpose new pitch adjustment...

Prognosis of failing components under intermittent faults is challenging since gradually deteriorate in duration and magnitude over time meanwhile show the stochasticity fault appearance disappearance. To address problem, this paper proposes an intelligent prognosis method for intermittently faulty electric scooter based on dual degradation processes. Firstly, detection isolation used to identify discrete isolate possible continuous components, where performance multiple condition improved...

In this article, a new event-triggering mechanism based prognosis scheme is proposed for discrete components in hybrid systems using degradation model selection. As an advantage over existing methods systems, more challenging case that multiple suffer from intermittent faults with unknown degradations investigated. By introducing structure where centralized used fault detection and isolation distributed adopted estimation, the performance under condition can be enhanced IMCSM estimation...

Classification based on polarimetric synthetic aperture radar (PolSAR) images is an emerging technology, and recent years have seen the introduction of various classification methods that been proven to be effective identify typical features many terrain types. Among regions study, Hunshandake Sandy Land in Inner Mongolia, China stands out for its vast area sandy land, variety ground objects, intricate structure, with more irregular characteristics than conventional land cover. Accounting...

2-deoxythiosugars are more stable than 2-deoxysugars occurring broadly in bioactive natural products and pharmaceutical agents. An effective direct methodology to stereoselectively synthesize α-2-deoxythioglycosides catalyzed by AgOTf has been developed. Various alkyl thiols thiophenols were explored the desired formed good yields with excellent α-selectivity. This method was further applied syntheses of S-linked disaccharides late-stage 2-deoxyglycosylation estrogen, L-menthol, zingerone...

Defoliation and accelerating ripening are important measures for cotton mechanization, judging the time of defoliation harvest relies heavily on boll opening rate, making it a crucial factor to consider. The traditional methods rate determination time-consuming, labor-intensive, destructive, not suitable wide range applications. In this study, relationship between change vegetation index obtained by unmanned aerial vehicle multi-spectrum ground was established realize rapid non-destructive...

This paper addresses diagnosis and prognosis problems for an electric scooter subjected to parameter uncertainties compound faults (i.e., permanent fault intermittent with non-monotonic degradation). First, the diagnostic bond graph in linear fractional transformation form is used model uncertain derive analytical redundancy relations incorporating nominal part part, based on which adaptive thresholds robust detection signature matrix isolation can be obtained. Second, enhanced unscented...

With the rapid development of mobile internet and pervasion Location-Based Service (LBS), location privacy has become an important issue. In this paper, we present DeCache, a modified protection system model, which pre-caches user-demanded LBS data. So users don't have to send network requests when they need access LBS. This is more secure than previous model with intermediate server. To realize make following contributions: 1) adding middleware in operating compute users' mobility pattern;...

In this paper, an adaptive Cuckoo search extreme learning machine (ACS-ELM)-based prognosis method is developed for electric scooter system with intermittent faults. Firstly, bond-graph-based fault detection and isolation carried out to find possible faulty components in the system. Secondly, submodels are decomposed from global model using structural decomposition, followed by (ACS)-based distributed estimation less computational burden. Then, as gradually deteriorates magnitude, possesses...

In this article, a fast krill herd algorithm is developed for prognosis of hybrid mechatronic system using the improved Wiener degradation process. First, diagnostic bond graph used to model and derive global analytical redundancy relations. Based on relations, fault signature matrix mode change isolation can be obtained. Second, in order determine true faults from suspected candidates after isolation, estimation method based adaptive square root cubature Kalman filter proposed when noise...

Robots play more important roles in daily life and bring us a lot of convenience. Somebody may need to cooperate with robots complete some specific tasks. But when people work robots, there remain significant differences human-human interactions human-robot interaction. It is our goal make look even human-like. We hope that the robot can following hand human who act force on robot. design controller which sense acting any point responds indirectly force. In addition, novel method used...

Download This Paper Open PDF in Browser Add to My Library Share: Permalink Using these links will ensure access this page indefinitely Copy URL DOI

The balance between vegetative and reproductive growth is the central objective in cotton production system, which associated with maturity yield. In China, manual topping (MT) has been performed many years prior to or during flowering period inhibit enhance growth. MT gradually being replaced by chemical (CT) mepiquat chloride (MC, 180 g ha−1, 98% soluble powder) due labor shortages increasing cost. To determine whether CT influences yield relative MT, we carried out field experiments at...

This paper deals with the fault diagnosis of nonlinear mechatronic system using bond graph and particle swarm optimization. The under investigation includes a DC motor load part. Nonlinear phenomena such as friction backlash are considered in monitored system. objective is to determine source estimate its magnitude. In order realize task application, modeling tool adopted carry out detection isolation. After potential faults that could lead observed symptom obtained, optimization utilized...

In the context of COVID-19 pandemic, validity Capital Asset Pricing Model (CAPM) in U.S. stock market before and after pandemic outbreak is tested, aiming to help investors have a deeper understanding relationship between risk return when large-scale social disasters occur.The sample includes daily data for 49 industry portfolios over 36 months from September 2018 August 2021, with total 754 observations.Through linear regression analysis, author concludes that timely implementation...

Cube and tensile samples of reduced activation ferritic/martensitic steel were formed at different laser powers scanning velocities using a selective melting process; the microstructural characteristics properties cube investigated in this study. The experimental results showed that SLMed CLF-1 with selected near-fully dense, relative density exceeded 99%. Meanwhile, there numerous nano-sized spherical needle-like precipitate dispersions distributed grains boundary grains, precipitates...

This paper presents a model-based distributed fault diagnosis method to solve the problem of in complex systems. In general, with increase scale and scope systems, complexity will also increase. order address these problems, system decomposition algorithm is used for model where whole decomposed into several local subsystems. Based on decomposition, can be carried out locally each subsystem, subsystem reduced. Finally, developed illustrated using hybrid circuit system, simulation results...

This paper proposes an inverse system algorithm based fault-tolerant control method for electric power steering (EPS) system. Firstly, EPS is modeled by bond graph (BG) technology. Then, a passive on developed in the case of sensor faults system, which applies copy original model as controller, and compares output with command to generate input controller. Finally, simulation results are presented illustrate that designed controller has capability, can guarantee maintain stability when occur.

This paper presents a model-based distributed fault diagnosis approach for electro-hydraulic suspension system by using the diagnostic hybrid bond graph (DHBG) technique and bat algorithm (BA). Electro-hydraulic is complex nonlinear if centralized used, some problems, like poor scalability high computationally cost, exist. To overcome these developed where DHBG model of global decomposed into several local submodels temporal causal technology. In each submodel, analytical redundancy...