Control-Relevant System Identification using Nonlinear Volterra and Volterra-Laguerre Models

One of the key impediments to the wide-spread use of nonlinear control in industry is the availability of suitable nonlinear models. Empirical models, which are obtained from only the process input-output data, present a convenient alternative to the more involved fundamental models. An important advantage of the empirical models is that their structure can be chosen so as to facilitate the controller design problem. Many of the widely used empirical model structures are linear, and in some cases this basic model formulation may not be able to adequately capture the nonlinear process dynamics. One of the commonly used nonlinear dynamic empirical model structures is the Volterra model, and this work develops a systematic approach to the identification of third-order Volterra and Volterra-Laguerre models from process input-output data.First, plant-friendly input sequences are designed that exploit the Volterra model structure and use the prediction error variance (PEV) expression as a metric of model fidelity. Second, explicit estimator equations are derived for the linear, nonlinear diagonal, and higher-order sub-diagonal kernels using the tailored input sequences. Improvements in the sequence design are also presented which lead to a significant reduction in the amount of data required for identification. Finally, the third-order off-diagonal kernels are estimated using a cross-correlation approach. As an application of this technique, an isothermal polymerization reactor case study is considered.In order to overcome the noise sensitivity and highly parameterized nature of Volterra models, they are projected onto an orthonormal Laguerre basis. Two important variables that need to be selected for the projection are the Laguerre pole and the number of Laguerre filters. The Akaike Information Criterion (AIC) is used as a criterion to determine projected model quality. AIC includes contributions from both model size and model quality, with the latter characterized by the sum-squared error between the Volterra and the Volterra-Laguerre model outputs. Reduced Volterra-Laguerre models were also identified, and the control-relevance of identified Volterra-Laguerre models was evaluated in closed-loop using the model predictive control framework. Thus, this work presents a complete treatment of the problem of identifying nonlinear control-relevant Volterra and Volterra-Laguerre models from input-output data

Herpes zoster: A case series with varied clinical presentations

Herpes zoster (HZ) is a viral disease that clinically presents as a painful vesicular rash restricted to the distribution of a sensory nerve, unilaterally. It usually results from the reactivation of the DNA virus varicella zoster, which causes chicken pox. The condition is characterized by the occurrence of multiple, painful vesicles, and ulceration which shows a typical unilateral distribution. This case series of HZ infections is an attempt to present different clinical presentations of the disease, showing both the facial and oral manifestations, which are successfully managed by the appropriate medical management

Luminescent Materials in Lighting, Display, Solar Cell, Sensing, and Biomedical Applications

This chapter comprises a broader extent of the luminescence phenomenon with the mechanism involved therein as well as applications. Typically, the up and down conversion and downshifting behavior of the optical materials have been elucidated in brief. The fundamental understanding of these optical materials has been described by using schematic representations. It is well documented that the rare earth-based optical materials are known for their luminescent enrichment due to availability of the ladder-like energy levels. These energy levels can be utilized for the excitation of the luminescent materials by using a suitable excitation source. In the process of development of luminescent materials, choice of host matrices and dopant ions is very crucial. Strong correlation of these optical materials has been shown with the current scenario of our society and daily life. In view of the ongoing research, nanophosphor, glasses, and quantum dots with size- and shape-dependent optical behavior have been given in detail. The involved mechanism and the energy transfer phenomenon have been well elucidated by schematic and figures for the evident explanation to the readers. Our emphasis is to elucidate these optical materials in the development of innovative multifunctional applications such as lighting, display, sensing, LEDs, solar cell, and biological applications

A MULTI-SCALE APPROACH TO FED-BATCH BIOREACTOR CONTROL

The rising energy costs, increased global competition in terms of both price and quality, and the need to make products in an environmentally benign manner have paved the way for the biological route towards manufacturing. Many of the products obtained by the biological route either cannot be produced, or are very difficult to obtain, by conventional manufacturing methods. Most of these products fall in the low volume/high value bracket, and it is estimated that the production of therapeutic proteins alone generated sales exceeding $25 billion in 2001. By increasing our understanding of these systems it may be possible to avoid some of the empiricism associated with the operation of (fed-)batch bioreactors. Considerable benefit, in terms of reduced product variability and optimal resource utilization could be achieved, and this work is a step in that direction.Biological reactors typically are governed by highly nonlinear behavior occuring on both a macroscopic reactor scale and a microscopic cellular scale. Reactions taking place at these scales also occur at different rates so that the bioreactor system is multi-scale both spatially and temporally. Since achievable controller performance in a model-based control scheme is dependent on the quality of the process model cite{mor89}, a controller based on a model that captures events occuring at both the reactor and cellular scales should provide superior performance when compared to a controller that employs a uniscale model. In the model considered for this work, the specific growth rate is used as a coupling parameter integrating the behavior of both scales. On the cellular level, flux distributions are used to describe cellular growth and product formation whereas a lumped-parameter reactor model provides the macroscopic process representation.The control scheme for the fed-batch bioreactor is implemented in two stages, and the substrate feed rate serves as the manipulated variable. Initially, a constrained optimal control problem is solved off-line, in order to determine the manipulated variable profile that maximizes the end of batch product concentration for the product of interest, while maintaining apre-specified, fixed final volume. The next step involves tracking of the optimal control trajectory, in closed-loop operation. The Shrinking Horizon Model Predictive Control (SHMPC) framework is used to minimize the projected deviations of the controlled variable from the specified trajectories. At every time step, the original nonlinear model is linearized and the optimization problem is formulated as a quadratic program, that includes constraints on the manipulated input and the final volume. Finally, the performance of the controller is evaluated, and strategies for disturbance compensation are presented. The results of this approach are presented for ethanol production in a baker's yeast fermentation case study

Leptospirosis and COVID-19 Co-Infection Manifesting as an Enhanced Thrombotic Phenomenon

Clinical manifestations of COVID-19 range from mild self-limiting illness to multi-organ dysfunction and acute respiratory distress syndrome (ARDS). Leptospirosis too manifests as mild or asymptomatic infection and only small number of patients progress to ARDS and develop systemic manifestation. COVID-19 and leptospira co infection can have fatal outcome because of augmented pathophysiological manifestations of both the disease. We here describe a case of leptospira and COVID-19 coinfection in a patient who had poor outcomes due to multi-organ involvement

Bilateral phyllodes tumor of the breast in a young nulliparous woman

Cystosarcoma phyllodes is a rare breast tumor with incidence of 1% of all the mammary tumors. Bilateral occurrence is very rare. Median age of presentation is 40-50 years. We present a case of 24 years old nulliparous female with phyllodes tumour developing in both the breasts one after another with a gap of five years. Patient underwent simple mastectomy on both sides. Histopathology report confirmed benign variety of cystosarcoma phyllodes on both sides

Coenzyme Q10 therapy in current clinical practice

Coenzyme Q10 (CoQ10) is a naturally occurring, lipid soluble, essential compound and is also known as ubiquinone. CoQ10 acts as an intermediate of the electron transport chain situated in membrane of mitochondria and vital for ATP production and cellular respiration. CoQ10 also serves as an intercellular antioxidant. All the clinical use of CoQ10 are based upon these two functions. CoQ10 levels are altered in a number of oncological as well as non-oncological diseases. Furthermore, recent data indicate that CoQ10 has an impact on the expression of many genes involved in metabolism, cellular transport, transcription control, and cell signaling, making CoQ10 a potent gene regulator. CoQ10 supplementation is useful in diseases associated with CoQ10 deficiency which includes primary and secondary CoQ10 deficiencies, fibromyalgia, diabetes mellitus, mitochondrial diseases, neurodegenerative diseases, cardiovascular disease, cancer, male infertility and periodontal disease. Clinical presentations of severe CoQ10 deficiency include severe infantile multisystemic disease, encephalomyopathy, isolated myopathy cerebellar ataxia and Leigh syndrome with growth retardation. Oral CoQ10 administration can correct CoQ10 deficiency since it increases CoQ10 tissue levels. CoQ10 therapy has no serious side effects in humans and new formulations have been developed that increase CoQ10 absorption and tissue distribution. Future trends involving CoQ10 in many diseases needs more clinical trials for better understanding of CoQ10 efficacy

Hand Gesture Recognition using Python

The goal for the project was to develop a new type of Human Computer Interaction system that subdues the problems that users have been facing with the current system. The project is implemented on a Linux system but could be implemented on a windows system by downloading some modules for python. The algorithm applied is resistant to change in background image as it is not based on background image subtraction and is not programmed for a specific hand type; the algorithm used can process different hand types, recognizes no of fingers, and can carry out tasks as per requirement. As it is stated within this paper, the main goals were reached. The application is capable of the gesture recognition in real-time. There are some limitations, which we still have to be overcome in future

Contactlesss Eddy Current Braking System in Automobiles

In mechanical type braking system which are being used now days to stop or retard the automobile by means of artificial frictional resistance. This causes skidding and wear & tear of the vehicle which may cause serious problems. If the speed of the vehicle is very high, then it will not provide high braking torque, which may cause less frictional resistance during braking action and it will cause problems like accidents. These drawbacks of mechanical type brakes can be overcome by a simple, effective and efficient mechanism of braking system which is called as �The Non contactless braking system or Eddy current braking System�. It is a non contact type braking system then it is an abrasion-free method for braking in automobiles. It makes use of the opposing tendency of Eddy current. Eddy current are the loops of or swirling electric current produced in a conductor,by changing the magnetic field .The change of magnetic field is required for generating flux by the principle of faraday law. In eddy currents braking energy such as kinetic energy transform into heat, which is an unused energy. In some applications, the useful energy is lost i.e not particularly desirable. But there are some practical applications such an application is the eddy current brake.[1]This paper report explores the working principle of eddy current brake mechanism. In eddy current braking, like a conventional friction brake, which is responsible for slowing an object, such as a train or a roller coaster etc. In the friction braking, the pressure is applied on two separate objects, but in eddy current braking an object is stopped by creating eddy currents through electromagnetic induction which creates resistance, and in turn either heat or electricity. For such a breaker, we give analytical formulas considering end effects for its magnetic field, eddy current distribution, forces according to the secondary relative permeability, and conductivity. The results given here are purely analytic.[2]The principle of braking in road vehicles involved the conversion of kinetic energy into heat. This heat energy conversion therefore demands and appropriate rate of heat dissipation if a reasonable temperature and performance stability are to be maintained. The electromagnetic brakes works in relatively cool condition thus it avoid problem that friction brake face by using a totally different working principle and installation location. By using electromagnetic braking as substitute retardation equipment, the friction braking may be used less as compared and therefore practically never reach high temperature. Thus by eddy current braking brakes have a longer life , and potential �brake fade� problem can be avoided, it is apparent that the electromagnetic brake is an essential compliment to the safe breaking of vehicles.[3

POLYCYSTIC OVARY SYNDROME: PATHOGENESIS, TREATMENT AND SECONDARY ASSOCIATED DISEASES

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy in women of reproductive age. It is characterized by hyperandrogenism, polycystic ovaries, and chronic anovulation along with insulin resistance, hyperinsulinemia, abdominal obesity, hypertension, and dyslipidemia as frequent metabolic traits (metabolic syndrome) that culminate in serious long-term consequences such as type 2 diabetes mellitus, endometrial hyperplasia, and coronary artery disease. It is one of the most common causes of anovulatory infertility. A complete understanding of the underlying Pathophysiology of PCOS is still lacking. Because of the heterogeneity of this disorder, there are most likely multiple underlying pathophysiologic mechanisms. Pathogenesis of PCOS is explaining as alteration in gonadotropin-releasing hormone secretion results in increased luteinizing hormone (LH) secretion. An alteration in insulin secretion and insulin action results in hyperinsulinemia and insulin resistance. A defect in androgen synthesis that results in increased ovarian androgen production.Treatment of PCOS include maintaining a normal endometrium, antagonizing the actions of androgens on target tissues, reducing insulin resistance (when present), and correcting anovulation. Women with polycystic ovary syndrome (PCOS) are at higher risk for several other health conditions as Insulin Resistance, Metabolic Syndrome, Type 2 Diabetes, Obesity, Heart Disease and High Blood Pressure (Cardiovascular Disease) &nbsp