Discrete-time output feedback sliding-mode control design for uncertain systems using linear matrix inequalities

An output feedback-based sliding-mode control design methodology for discrete-time systems is considered in this article. In previous work, it has been shown that by identifying a minimal set of current and past outputs, an augmented system can be obtained which permits the design of a sliding surface based upon output information only, if the invariant zeros of this augmented system are stable. In this work, a procedure for realising discrete-time controllers via a particular set of extended outputs is presented for non-square systems with uncertainties. This method is applicable when unstable invariant zeros are present in the original system. The conditions for existence of a sliding manifold guaranteeing a stable sliding motion are given. A procedure to obtain a Lyapunov matrix, which simultaneously satisfies both a Riccati inequality and a structural constraint, is used to formulate the corresponding control to solve the reachability problem. A numerical method using linear matrix inequalities is suggested to obtain the Lyapunov matrix. Finally, the design approach given in this article is applied to an aircraft problem and the use of the method as a reconfigurable control strategy in the presence of sensor failure is demonstrated

Federated learning in gaze recognition (FLIGR)

The efficiency and generalizability of a deep learning model is based on the amount and diversity of training data. Although huge amounts of data are being collected, these data are not stored in centralized servers for further data processing. It is often infeasible to collect and share data in centralized servers due to various medical data regulations. This need for diversely distributed data and infeasible storage solutions calls for Federated Learning (FL). FL is a clever way of utilizing privately stored data in model building without the need for data sharing. The idea is to train several different models locally with same architecture, share the model weights between the collaborators, aggregate the model weights and use the resulting global weights in furthering model building. FL is an iterative algorithm which repeats the above steps over defined number of rounds. By doing so, we negate the need for centralized data sharing and avoid several regulations tied to it. In this work, federated learning is applied to gaze recognition, a task to identify where the doctor’s gaze at. A global model is built by repeatedly aggregating local models built from 8 local institutional data using the FL algorithm for 4 federated rounds. The results show increase in the performance of the global model over federated rounds. The study also shows that the global model can be trained one more time locally at the end of FL on each institutional level to fine-tune the model to local data

Effect of dimethyl sulfoxide on mouse embryo fibroblasts: inhibition of plasminogen activator inhibitor deposition and interference with early events of serum-stimulated growth

Quiescent and serum-stimulated cultures of Swiss mouse embryo fibroblasts (MEF) showed alterations in cell morphology including an enlargement in size upon treatment with 2% dimethyl sulfoxide (DMSO). Treatment of MEF and monkey kidney epithelial cells (MK2) with 2% DMSO at the early periods of serum-stimulated growth inhibited RNA, protein and DNA synthesis. DMSO treatment of cells at late stages of serum-stimulated growth (MEF after 1 hr and MK2 cells after 3 hr of stimulation) had little effect on DNA and protein synthesis although cell enlargement occurred in these cells. When the [35S]methionine labelled proteins of the control and the DMSO treated cells were analysed by high resolution polyacrylamide gel electrophoresis, no apparent difference was observed in the pattern of intracellular proteins of these cells. In contrast, the extracellular levels of two serum-induced secreted proteins of MEF (Mr 48,000 and 26,000) were dramatically reduced by DMSO treatment. The DMSO sensitive 48 kDa protein was found to be the major component of the extracellular matrix, while the 26 kDa protein was not. The 48 kDa protein was identified as plasminogen activator inhibitor (PAI-1). Densitometric quantitation showed a gradual accumulation of this protein in the matrix of serum-stimulated cells. The deposition of this protein in the matrix was inhibited by DMSO. Flow-cytometric quantitation of indirect immunofluorescence indicated higher intracellular levels of the 48 kDa protein in fetal calf serum (FCS) + DMSO treated cells, suggesting that the low level of this protein in the medium of DMSO treated cells is probably due to lack of transport of this protein from the cells into the medium

An efficient hydro-crop growth prediction system for nutrient analysis using machine learning algorithm

The hydro nutrient management (HNM) for crop yield is effectively improved using proposed system. A hydro-crop growth prediction system (HCGPS) is designed using machine learning. The reconfigurable nutrients uptake crop yield prediction rate is enhanced. This proposed HCGPS is used to predict the crop yield by considering input parameters such as nutrient index (NI), electric conductivity limit (ECL), ion concentration factors (ICF) and dry weight of the crop and crop yield rate (CYR) to analyze the positive and negative correlation with crop growth. The proposed system is used to find correlation Index of input and output parameters to determine the prediction rate of crop yield. The proposed design improves smart prediction rate and efficiency of crop growth rate with optimal utilization of input variables. This proposed HCGPS is very helpful to achieve good quality yield with optimal utilization of input parameters

Promoter hypermethylation profile of tumor-associated genes p16, p15, hMLH1, MGMT and E-cadherin in oral squamous cell carcinoma

Aberrant promoter hypermethylation of tumor-associated genes leading to their inactivation is a common event in many cancer types. Using a sensitive restriction-multiplex PCR method, we studied the promoter hypermethylation profile of the p16, p15, hMLH1, MGMT and E-cad genes in oral squamous cell carcinoma (OSCC) of Indians. We analyzed a total of 51 samples for the p15 tumor-suppressor gene and 99 samples for each of the remaining genes. Our studies indicate an incidence of promoter hypermethylation of 23% each for p16 and p15, 8% for hMLH1, 41% for MGMT and 35% for E-cad. We observed aberrant hypermethylation of the promoter region of at least 1 of these genes in 74.5% of cases (n = 51) for which all the 5 genes were studied. Abnormal methylation was detected in tumors irrespective of stage and location in the oral cavity, whereas no abnormal methylation was detectable in normal oral squamous tissues obtained from 25 OSCC patients. Detection of aberrant hypermethylation patterns of cancer-associated genes listed above is therefore suitable for diagnosis of OSCC in individuals at high risk for this disease

A Modulation Technique for Sensorless Control of Switched Reluctance Motor

The switched reluctance motor (SRM) uniquely bears several merits with respect to other motor configurations. Especially, the construction of the rotor is simple in the sense that it neither contains copper not contains permanent magnets. Because of this construction, likelihood of rotor’s failure is less than the other motor configurations. This makes this motor more suitable for harsh environments. On the flip side, this motor cannot directly operate with AC or DC power source and needs electronic commutation. For commutation, the information on instantaneous orientation of the rotor is essential. Since inclusion of appropriate sensor adds to the cost and complexity of the system, sensor-less commutation of SRM gained interest among the researchers and has been studied extensively in literature. The techniques for sensorless control of SRM can be broadly classified into Active phase and Idle phase techniques. Idle phase techniques are generally believed to be not suitable for high speed operation beause of tail current in a phase, i.e., because of inductive nature of the phase, it takes time for flow of current to stop. This paper proposes a novel idle phase technique that is conducive for high speed operation of switched reluctance motor

Cytotoxic and genotoxic effects of cleistanthin B in normal and tumour cells

Cleistanthin B, one of the toxic constituents of Cleistanthus collinus, was found to be cytotoxic to normal and tumour cells. In comparison with normal cells, tumour cells were sensitive to lower doses of toxin. The 50% growth inhibition (GI50) values for normal cell lines were from 2 × 10-5 to 4.7 × 10-4 M and for tumour cells the values ranged from 1.6 × l0-6 to 4 × l0-5 M. Short exposure (30 min) of Chinese hamster ovary (CHO) cells to cleistanthin B at 1-6 μg/ml resulted in extensive chromatid and isochromatid breaks and gaps. However there was no significant increase in cell death and DNA strand breaks in cells treated under the above conditions. Cleistanthin B induced micronucleus formation in cultured lymphocytes in a dose-dependent manner. CHO cells treated with high doses of cleistanthin B showed a decrease in cell viability and a concomitant increase in DNA strand-breaks. The cell death appears to be due to apoptosis since nucleosome-like ladders were observed in the treated cells when the DNA was electrophorized in agarose gels

Mysterious Trippings of NGL Turbo Expanders on Qatargas Mega LNG Train

Case StudyContent: •Problem Statement •Installation Reference •Purpose of NGL expanders •Construction of NGL expanders •Problem Description •Findings & Analysis •Problem Resolution •Challenges Faced •Q &

HPLC-UV Quantitative Analysis of Acrylamide in Snack Foods of India

An investigation was carried out to determine acrylamide content in 51 popular snacks food of India by using High Pressure Liquid Chromatography (HPLC) Instrument with UV detection method. The method entails acetone extraction of acrylamide, clean up by solid extraction cartridges, isocratic elution with mobile phase of HPLC grade water, acetonitrile and formic acid followed by detection at 210 nm. The limit of detection and the limit of quantification for this method were 5.12 and 17.08 μg/kg, respectively. The mean recoveries of acrylamide obtained by using spiked samples ranged from 91 per cent to 101.33 per cent. Acrylamide concentrations in the five groups of snacks ranged from 788.99 - 4191.82 μg/ for extruded and deep fat fried snack, 372 to 6391μg/ kg for deep fat fried food, 435-3147μg/kg for baked food, 434-1307 μg/kg for breakfast cereal and 471-1520 μg/kg for other snacks. Among the food products, snack foods purchased from unorganised sector showed highest concentration of acrylamide