Optimal Input Design for Active Parameter Identification of Dynamic Nonlinear Systems

There are many important aspects to be considered while designing optimal excitation signal for system identification experiment in control applications. Active parameter identification is an important issue in system and control theory. In this dissertation, the problem of optimal input design for active parameter identification of dynamic nonlinear system is addressed. Real life physical systems are identified by excitation with a suitable input signal and observing the resulting output behavior of the system. It is important to choose the input signal intelligently in the sense that it is responsible to determine the accuracy and nature of the unknown system characteristics. This leads to a spurred interest in designing such an optimal excitation signals that can yield maximal information from the identification experiment. The information obtained from parameter identification is usually not accurate due to incomplete knowledge of the system, disturbance as exogenous inputs and noisy measurements. Hence, the input spectrum is designed in such a way that it can improve the system performance and shape the quality of obtained information. A welldesigned input signal can maximize the amount of information and reduce the experimental cost and time. The input signal is usually given some a-priori characteristics (knowledge on the pdf) so that \u201cexcitation\u201d of the system is guaranteed. In this thesis, a closed-loop method is investigated which is able to improve the parameter identification on the basis of the actual system\u2019s behavior. The effectiveness of the proposed algorithm is presented by the experimental results which corresponds to the perfect identification of the unknown parameter vector. The major technical contribution of this work is to propose an optimal feedback input design method for active parameter identification of dynamic nonlinear systems. The proposed framework can design such optimal excitation signals, considering the information from the identified parameters, that can maximize the amount of information from the identified parameters, guarantee to meet the specified control performance and minimize some cost function of the error covariance matrix of the identified parameters. The problem is formulated in a receding horizon framework where extended Kalman filter is used for system identification and the optimal input is designed in a nonlinear model predictive control framework. In order to carry out a comparison study, also Unscented Kalman Filter and Gaussian Sum Filter are used for the active parameter identification of dynamic nonlinear system. Towards this end, a suitable optimality criterion related to the unknown parameters is proposed and motivated as an information measure. The aim of the optimal input design is to yield maximal information from the unknown system by minimizing the cost related to the unknown parameters while maintaining some process performance and satisfying the possible constraints. Simulations are performed to show the effectiveness of the proposed algorithm

Genotypic response of chickpea (Cicer arietinum L.) for resistance against gram pod borer (Helicoverpa armigera)

Background: Chickpea is an important pulse crop of Pakistan. The pod borer, Helicoverpa armigera (Hubner), is the major pest in most of the chickpea growing areas of the country. A field trial was carried out at Entomological Research Area, Ayub Agriculture Research Institute (AARI), Faisalabad, during growing season of 2012-13 to evaluate the resistance of chickpea genotypes against gram pod borer (Helicoverpa armigera).Methods: Experiments were conducted in randomized complete block design (RCBD) with four replications having plot size of 3 ft × 20 ft. Morphological characters of chickpea like pod trichome, pod wall thickness, pod length, pod breadth, pod area and number of pods per plant were measured. The pod borer larval population/pod infestation was recorded from fifteen randomly selected plants per plot after ten days interval.Results: It was found that the genotypes which had higher trichomes length and density and pod wall thickness were more resistant against Helicoverpa infestation. Significant genetic variation for resistance against Helicoverpa armigera attack was found in chickpea and variety K-70005 showed resistant behavior followed by K-08004 and K-60062.Conclusions: It was concluded from prescribed study that the most susceptible genotypes were K-70005, K-08004 and K-70008 for the attack of Helicoverpa armigera to reduce grain yield

Microsatellite marker based genetic diversity among four varieties of Pakistani Aseel chicken

Indian Aseel chicken (Gallus gallus) is traditionally used as a favorite game bird all over the world. Bird fighting communities of Pakistan are the major source of its conservation and there are at least four distinctively recognized varieties of Aseel chicken based upon selective breeding, geographical location and color patterns. A pioneering study on genetic diversity of these varieties namely Lakha (n=17), Mushki (n=19), Mianwali (n=19) and Peshawari (n=13) was undertaken using FAO recommended 10 microsatellite loci. A total of 91 alleles were observed in 4 varieties of Aseel chicken with an average of 9.1 alleles per locus. Number of alleles varied between 4 to 8 in Lakha, 4 to 9 in Mushki, 3 to 10 in Mianwali and 3 to 7 in Pashawari. Mean polymorphic information content values were 0.67, 0.69, 0.71 and 0.65 in individual varieties, respectively. Mean observed and expected heterozygosity index values of 0.3941 and 0.7376 were recorded in Lakha, 0.4105 and 0.7468 for Mushki, 0.4105 and 0.7718 Mianwali and 0.3692 and 0.7191 for Peshawari. Mean Fixation index (Fst) value was calculated as 0.1264. Highest Nei's standard genetic distance (Ds) value of 1.0735 was observed between Mushki and Peshawari, whereas its value was minimum (0.3533) between Lakha and Mushki. This report describes genetic diversity of Aseel chicken in Pakistan and provides foundation data to initiate extensive and more comprehensive studies on indigenous chicken genetic resource conservation and its future utilization in commercial breeding programs. (C) 2011 PVJ. All rights reserve

Hygroscopic properties following drying affects wood consumption by Odontotermes obesus

The relationship between drying and hygroscopic ability of Crateva adansonii and Populus deltoides woods to resist feeding by Odontotermes obesus was studied. Woods were dried under the sun and in the oven for a range of 5-25 days and then these were exposed to termites for 25 days in underground pits in Randomized Complete Block Design pattern with five replications. Results showed that lowest moisture gain was observed at a short time for drying with each method. Weight loss after termites’ exposure was more in less dried sap and heartwood of either plant species. The practical implication of these results is discussed

Hygroscopic properties following drying affects wood consumption by Odontotermes obesus

The relationship between drying and hygroscopic ability of Crateva adansonii and Populus deltoides woods to resist feeding by Odontotermes obesus was studied. Woods were dried under the sun and in the oven for a range of 5-25 days and then these were exposed to termites for 25 days in underground pits in Randomized Complete Block Design pattern with five replications. Results showed that lowest moisture gain was observed at a short time for drying with each method. Weight loss after termites’ exposure was more in less dried sap and heartwood of either plant species. The practical implication of these results is discussed

Diagnostic Efficacy of MRCP and Ultrasound on Obstructive Jaundice-A Prospective Study

Background: Obstructive jaundice is a common pathological problem that occurs when there is an obstruction to the passage of conjugated bilirubin from liver cells to intestine. Bile, a digestive fluid secreted and produce by the liver. Most common cause of obstructive jaundice is due to gallstones. Objective: The aim of our study was to evaluate the diagnostic Efficacy of MRCP and Ultrasound on obstructive jaundice. Study design: A cross-sectional prospective study was performed. Material & Method: A cross-sectional prospective study was performed in 50 patients who came with the provisional diagnosis of obstructive jaundice were referred to ultrasound for primitive diagnosis and were then shifted to MRCP for a detailed diagnosis. The data was collected from the outpatient department facility of Pakistan Kidney and Liver Institute   Hospital, Lahore. After informed consent, data was collected from MRI GE 1.5 Tesla, Ultrasound Canon Xanio. Results: The results revealed that there are 50 patients of obstructive jaundice. 20 were females’ patients and 30 were males’ patients, with age raging from 20-40 years. There were 17 patients out of  50 in our study which ultrasound showed negative results that were positive on MRCP there were 28 patients that were positive on both ultrasound and MRCP. There were 3 patients that were positive on ultrasound but negative on MRCP and 2 patients that were negative on both modalities Conclusion: Our study concluded that higher ratio of males then females in our sample size, RHC was positive in all the patients with dominant cause of jaundice was stone with in biliary channel. We found that MRCP has better efficiency comparative to ultrasound to detect jaundice and its etiology i.e., 90% true positive. Keywords: Magnetic resonance cholangiopancreatography, Ultrasonography, Obstructive jaundice DOI: 10.7176/JHMN/91-03 Publication date:July 31st 202

Sublethal and transgenerational effects of synthetic insecticides on the biological parameters and functional response of Coccinella septempunctata (Coleoptera: Coccinellidae) under laboratory conditions

Synthetic insecticides have been an inevitable part of plant protection throughout the world. Sublethal effects of these chemicals on beneficial insect species are one of the contemporary issues these days. Using the age-stage, two-sex life table model, this study evaluated the sublethal and transgenerational effects of six synthetic insecticides (imidacloprid, thiamethoxam, lambda-cyhalothrin, cypermethrin, chlorpyrifos and profenofos) commonly applied to winter vegetables, on the fitness and predation of the seven-spotted ladybeetle, Coccinella septempunctata, which is an efficient predator of aphids worldwide. According to results, all insecticides at their sublethal doses (LC30) significantly suppressed the emergence of adults, adult weight, fertility and fecundity of the parental generation compared to control treatment. The larval stage was prolonged and oviposition, fecundity and total longevity of the adult beetles were decreased in unexposed progeny whose parents were exposed to sublethal doses of all insecticides. Moreover, the biological parameters of adults, including the intrinsic rate of increase (r), finite rate of increase (λ) and net reproductive rate (R0) were significantly reduced when exposed to sublethal doses of insecticides. The predation rate of the F1 generation adults was also decreased after exposure to the sublethal doses of insecticides. However, chlorpyrifos, profenofos, lambda-cyhalothrin and cypermethrin exhibited more deleterious effects on the fitness and population parameters of beetles than imidacloprid and thiamethoxam

Increasing frailty is associated with higher prevalence and reduced recognition of delirium in older hospitalised inpatients: results of a multi-centre study

Purpose: Delirium is a neuropsychiatric disorder delineated by an acute change in cognition, attention, and consciousness. It is common, particularly in older adults, but poorly recognised. Frailty is the accumulation of deficits conferring an increased risk of adverse outcomes. We set out to determine how severity of frailty, as measured using the CFS, affected delirium rates, and recognition in hospitalised older people in the United Kingdom. Methods: Adults over 65 years were included in an observational multi-centre audit across UK hospitals, two prospective rounds, and one retrospective note review. Clinical Frailty Scale (CFS), delirium status, and 30-day outcomes were recorded. Results: The overall prevalence of delirium was 16.3% (483). Patients with delirium were more frail than patients without delirium (median CFS 6 vs 4). The risk of delirium was greater with increasing frailty [OR 2.9 (1.8–4.6) in CFS 4 vs 1–3; OR 12.4 (6.2–24.5) in CFS 8 vs 1–3]. Higher CFS was associated with reduced recognition of delirium (OR of 0.7 (0.3–1.9) in CFS 4 compared to 0.2 (0.1–0.7) in CFS 8). These risks were both independent of age and dementia. Conclusion: We have demonstrated an incremental increase in risk of delirium with increasing frailty. This has important clinical implications, suggesting that frailty may provide a more nuanced measure of vulnerability to delirium and poor outcomes. However, the most frail patients are least likely to have their delirium diagnosed and there is a significant lack of research into the underlying pathophysiology of both of these common geriatric syndromes

MPC based optimal input design for nonlinear system identification

A combined nonlinear model predictive control with extended Kalman filter strategy has been proposed for optimal input design. As the designed controller depend on the identified parameters, the achievable performance highly depends on the quality of the identified information. The degradation in achieving the desired control performance is quantified b y introducing an optimality criteria which minimize the error covariance matrix of the identified parameters. The major contribution is using the information of the system parameter at every sample time to improve the control performance at next time step. The the performance of the proposed algorithm is verified by numerical simulations for a example system

Robust integrated lateral guidance and control of UAVs

In this paper, a novel guidance scheme is presented for UAVs using the Integrated Guidance and Control (IGC) framework. The proposed guidance scheme is derived using H 1e Loop Shaping Design Procedure (LSDP). To recover from an initial cross track error, the proposed guidance algorithm produces such aileron commands that ensure the roll maneuvers without saturating the roll angle. The shaping of the open loop plant is carried out using the pre and post weights and then the robust stabilization is done by using the normalized left coprime factor uncertainty. The performance and robustness of the system are verified by introducing parametric uncertainties in to the system model. The results of the proposed scheme are verified by implementing it on a complete 6-DOF nonlinear model in the presence of wind disturbance. The simulation results indicate the effectiveness and robustness of the proposed guidance algorithm