Inverse Methods for Load Identification Augmented By Optimal Sensor Placement and Model Order Reduction

Design problems require accurate characterization of loads acting on a structure. One way to estimate the loads is through experimentally measured structural response. This is known as the inverse problem. The instrumented structure essentially acts as its own transducer. It is well known that the inverse problems tend to be highly ill-conditioned. This dissertation proposes several novel time domain and modal domain algorithms for estimating multiple dynamic loads exciting a structure from structural response measured at a finite number of optimally placed non-collocated sensors on the structure. The optimal placement of sensors is necessary to counter the inherent limitation of such inverse problems - ill-conditioning. Solution procedures based on construction of D-optimal design as well as sparse nature of mass, damping and stiffness matrices are proposed and implemented to determine the optimum locations of sensors that will provide the most precise load estimates. Both strain measurements using strain gages and acceleration measurements using accelerometers have been given due attention. Improvements in the load identification algorithms, based on model order reduction and reduced modal parameters, are further proposed to reconstruct the input forces accurately. Load identification techniques based on dynamic programming and Markov parameters have also been studied in this work. Several limitations to these existing techniques have been identified. An attempt has been made in this dissertation to address the identified shortcomings based on D-optimal design for obtaining optimal sensor locations on the structure and model order reduction for computational cost reduction. Both experimental measurements as well as numerical simulations have been performed in order to validate the proposed techniques. The experimental validation is done using a simple beam clamped at the base and attached to a shaker head. The focus of this example is to reconstruct the input forces exciting the structure through the shaker head. Numerical simulations are performed on the computational models developed in finite element tool ANSYS that works in close conjunction with MATLAB. Numerical sensitivity analyses are further performed to study the effect of uncertainties (noise) in experimental data as well as in the model; the techniques are validated to be robust - even with the presence of noise, the applied loads are recovered accurately

Awareness and Compliance in Contact Lens Wearers: Case Study

Purpose: To assess the contact lens compliance rate by using a self-administrated validated questionnaire, the level of awareness, compliance & detectable behavioral changes, patterns or trends in contact lens users. Methods: A questionnaire ,Cross sectional prospective study to understand the compliance in contact lens wearers, the questionnaires were distributed randomly among the users at various clinical & optical outlets. Based on various studies, and taking into account time constraints the sample size of 40 was taken. The mean age of 24 years was taken without any ocular pathology and systemic disease affecting the ocular health. Result: The majority of 87% of the subjects studied, preferred the monthly modality and 13 % preferred conventional yearly replacement lenses. Considering average duration of wear 64% of the subjects showed non- compliance and prolonged their wearing schedules beyond 8 hours. 38% of the contact lens users were not taking optimum care of the lens cases. A majority of 50% of the subjects rated better cosmetic appearance the most important factor, while 25% of them rated cosmetic & better vision equally important. 68% knew the availability of extended wear contact lenses that can be worn during sleep. Optical outlets are the places where the patient is more motivated for soft contact lens. Conclusion: Cost and convenience are two factors that must be considered when educating patients about proper lens care regimens. In addition, compliance is more likely if the patient is satisfied with the medical visit

A study on development changes in essential oil content and composition in Cymbopogon flexuosus cultivar Suvarna

Cymbopogon flexuosus (Steud.) cv. Suvarna produces an essential oil with unique lemon like aroma which is broadly used in flavors, fragrance, perfumery and pharmaceuticals. Here we report changes in essential oil content and compositions during C. flexuosus cv. Suvarna leaf development, leaf positions and leaf age. Essential oils were isolated by hydro-distillation of leaves harvested at six different developmental stages (10-50 days), 1st-5th leaf positions and three parts (basal, middle and apical) of the leaves. Analyses of essential oils by gas chromatography and GC-MS have identified 20 different terpenoids constituents with citral as the major monoterpene. The study showed that essential oil content was highest in early stages (10-20 days) of leaf development, then declined substantially. Similar pattern of essential oil content was observed between the 1st-5th leaf positions and the basal-apical parts within a leaf. Essential oil compositions were also markedly fluctuated. Percentage together of geranyl acetate and geraniol declined rapidly from 32% to 4% on 10th and 20th days, respectively; while percentage of citral (geranial + neral) increased correspondingly from 56% to 81% on 10th and 20th days, respectively. Similar changes in monoterpene composition were observed in leaf positions and leaf age (basal to apical part). Thus the study revealed that accumulation of essential oil depends on the developmental stages of the concerned plant parts and changes in essential oil content is also reflected by compositional changes in oil constituents

Geranyl acetate esterase (GAE) inhibitory activity of Neolamarckia cadamba fruit extract

Neolamarckia cadamba commonly known as the kadamb tree-is well known in Ayurveda and other traditional literature in India for it’s plenty of medicinal properties. Here we report the unique property of the methanol extract of its fruit and a compound isolated from it to inhibit the geranyl acetate esterase (GAE) of lemongrass. The GAE inhibitory activities of the methanol extract and the compound were determined by three procedures, spectrophotometric para-nitrophenyl acetate (p-NPA) assay, polyacrylamide gel electrophoresis (PAGE) and gas chromatography (GC). The results of p-NPA assay revealed that the fruit extract and its compound (10 mg/ml) caused significant inhibition (45%) of GAE activity as compared to the control. PAGE analysis revealed complete inhibition of one of the major isoenzyme of GAE (isoenzyme-II) by both the fruit extract and its isolated constituent. Gas chromatographic analysis showed the fruit extract and its compound caused drastic inhibition of GAE isoenzyme-II by 36 and 46%, respectively. The presence of –C=O and –OH groups in the compound as revealed by FTIR analysis indicated that it belongs to flavonoids. To the best of our knowledge this is the first report on GAE inhibitory activity of N. cadamba fruit methanol extract and its isolated constituent which could be implicated in the future to decipher the catalytic mechanism of GAE. The purification and detailed characterization of the isolated compound is in progress

A Review of ECG signals for Human Emotion Detection

This article evaluates the present development by means of literature review in determining the association between emotions, mainly worry, and the various physiological signals with special attention on the exclusive patterns of the electrocardiogram or ECG waveform. An initial investigation was carried out to evaluate which aspects in the ECG waveform can be most suitably related with worry, except from those. Hence, it has been observed that emotion identification utilizing particular aspects of ECG is investigated to a lesser degree compared to other physiological reactions like speech signals, skin conductance and temperature, facial expression, heart rate and blood pressure. With the initial investigation, it was further discovered that the T waves levels out consequently and there is some likelihood of P waves

Biodegradable microparticulate drug delivery system of diltiazem HCl

The efficacy of a drug in a specific application requires the maintenance of appropriate drug blood level concentration during a prolonged period of time. Controlled release delivery is available for many routes of administration and offers many advantages (as microparticles and nanoparticles) over immediate release delivery. These advantages include reduced dosing frequency, better therapeutic control, fewer side effects, and, consequently, these dosage forms are well accepted by patients. Advances in polymer material science, particle engineering design, manufacture, and nanotechnology have led the way to the introduction of several marketed controlled release products and several more are in pre-clinical and clinical development. The objective of this work is to prepare and evaluate diltiazem HCl loaded albumin microparticles using a factorial design. Albumin (natural polymer) microparticles were prepared by emulsion heat-stabilization method. Selected formulations were characterized for their entrapment efficiency, particle size, surface morphology, and release behavior. Analysis of variance for entrapment efficiency indicates that entrapment efficiency is best fitted to a response surface linear model. Surface morphology was studied by scanning electron microscopy. Scanning electron microscopy of the microparticles revealed a spherical, nonporous and uniform appearance, with a smooth surface. The geometric mean diameter of the microparticles was found to be 2-9 µm, which more than 75% were below 3.5 µm and drug incorporation efficiency of 59.74 to 72.48% (w/w). In vitro release profile for formulations containing diltiazem HCl loaded BSA microparticles with heat stabilization technique shows slow controlled the release of the drug up to 24 hours. The release pattern was biphasic, characterized by an initial burst effect followed by a slow release. All selected microparticles exhibited a prolonged release for almost 24 hours. On comparing regression-coefficient (r²) values for Hixson Crowel, Higuchi and Peppas kinetic models, different batches of microparticles showed Fickian, non-Fickian, and diffusion kinetics. The release mechanism was regulated by D:P ratio. From the statistical analysis it was observed that as the drug:polymer (D:P) ratio increased, there was a significant increase in the encapsulation efficiency. Based on the particle size, entrapment efficiency and physical appearance, DTM-3 formulations were selected for in vivo release study and stability study. The in vivo result of drug loaded microparticles showed preferential drug targeting to liver followed by lungs, kidneys and spleen. Stability studies showed that maximum drug content and closest in vitro release to initial data were found in the formulation stored at 4 ºC. In present study, diltiazem HCl loaded BSA microparticles were prepared and targeted to various organs to satisfactory level and were found to be stable at 4 ºC.A eficácia terapêutica de um fármaco depende da manutenção de seu nível plasmático adequado em determinado intervalo de tempo. Nesse sentido, a liberação modificada de fármacos está disponível em muitas vias de administração e oferece muitas vantagens (como micropartículas e nanopartículas) quando comparada às formulações de liberação imediata. Essas vantagens incluem reduzida frequência da dosagem, melhor controle terapêutico e menos efeitos colaterais. Assim sendo, esses produtos apresentam maior aceitação pelos pacientes. Os avanços na ciência dos materiais, na engenharia das partículas, em manufatura e em nanotecnologia permitiram a introdução no mercado de vários produtos de liberação modificada e vários outros se encontram em desenvolvimento pré-clínico e clínico. O objetivo do presente trabalho foi preparar e avaliar o fármaco cloridrato de diltiazem associado a micropartículas de albumina utilizando planejamento fatorial. As micropartículas de albumina, um polímero natural, foram preparadas por método de emulsão empregando estabilização por calor. As formulações selecionadas foram caracterizadas no que se refere à sua eficiência de encapsulamento, tamanho médio de partículas, morfologia de superfície e perfil de liberação do fármaco. A análise de variância relativa à eficiência de encapsulamento indicou superfície de resposta linear. Com referência à morfologia superficial, essa foi avaliada empregando microscopia eletrônica de varredura. Essa análise revelou micropartículas esféricas, não porosas e de aparência uniforme, com superfície lisa. O diâmetro médio das micropartículas foi entre 2 e 9 µm, sendo que mais de 75% das micropartículas se apresentaram abaixo de 3,5 µm. Além disso, a eficiência de encapsulamento foi entre 59,74 e 72,48%. Quanto ao ensaio para avaliação do perfil de liberação in vitro do fármaco associado às micropartículas, as formulações apresentaram liberação lenta até 24 horas. O comportamento foi caracterizado por liberação inicial (efeito burst) seguida por liberação lenta. Todas as fórmulas selecionadas apresentaram liberação prolongada por aproximadamente 24 horas. Na comparação entre os valores de coeficientes de regressão (R²), os modelos propostos por Hixson Crowel, Higuchi e Peppas, para diferentes formulações de micropartículas, demonstraram cinética de liberação de acordo com modelo Fickiano e não-Fickiano. O mecanismo de liberação do fármaco foi regulado pela razão entre o fármaco e o polímero. A análise estatística revelou significativo aumento da eficiência de encapsulamento quando essa razão aumentou. As avaliações relativas à análise dimensional das micropartículas, à eficiência de encapsulamento do fármaco e à morfologia permitiram a seleção da formulação DTM-3 para os ensaios de liberação in vivo e para o estudo da estabilidade. O ensaio de liberação in vivo do fármaco associado às micropartículas demonstrou sítio-alvo preferencial no fígado, seguido pelos pulmões rins e baço. No presente estudo, as micropartículas de albumina contendo cloridrato de diltiazem foram adequadamente preparadas e orientadas satisfatoriamente para vários órgãos. Além disso, a formulação selecionada apresentou estabilidade físico-química a 4 ºC

Biodegradable microparticulate drug delivery system of diltiazem HCl

A eficácia terapêutica de um fármaco depende da manutenção de seu nível plasmático adequado em determinado intervalo de tempo. Nesse sentido, a liberação modificada de fármacos está disponível em muitas vias de administração e oferece muitas vantagens (como micropartículas e nanopartículas) quando comparada às formulações de liberação imediata. Essas vantagens incluem reduzida frequência da dosagem, melhor controle terapêutico e menos efeitos colaterais. Assim sendo, esses produtos apresentam maior aceitação pelos pacientes. Os avanços na ciência dos materiais, na engenharia das partículas, em manufatura e em nanotecnologia permitiram a introdução no mercado de vários produtos de liberação modificada e vários outros se encontram em desenvolvimento pré-clínico e clínico. O objetivo do presente trabalho foi preparar e avaliar o fármaco cloridrato de diltiazem associado a micropartículas de albumina utilizando planejamento fatorial. As micropartículas de albumina, um polímero natural, foram preparadas por método de emulsão empregando estabilização por calor. As formulações selecionadas foram caracterizadas no que se refere à sua eficiência de encapsulamento, tamanho médio de partículas, morfologia de superfície e perfil de liberação do fármaco. A análise de variância relativa à eficiência de encapsulamento indicou superfície de resposta linear. Com referência à morfologia superficial, essa foi avaliada empregando microscopia eletrônica de varredura. Essa análise revelou micropartículas esféricas, não porosas e de aparência uniforme, com superfície lisa. O diâmetro médio das micropartículas foi entre 2 e 9 µm, sendo que mais de 75% das micropartículas se apresentaram abaixo de 3,5 µm. Além disso, a eficiência de encapsulamento foi entre 59,74 e 72,48%. Quanto ao ensaio para avaliação do perfil de liberação in vitro do fármaco associado às micropartículas, as formulações apresentaram liberação lenta até 24 horas. O comportamento foi caracterizado por liberação inicial (efeito burst) seguida por liberação lenta. Todas as fórmulas selecionadas apresentaram liberação prolongada por aproximadamente 24 horas. Na comparação entre os valores de coeficientes de regressão (R²), os modelos propostos por Hixson Crowel, Higuchi e Peppas, para diferentes formulações de micropartículas, demonstraram cinética de liberação de acordo com modelo Fickiano e não-Fickiano. O mecanismo de liberação do fármaco foi regulado pela razão entre o fármaco e o polímero. A análise estatística revelou significativo aumento da eficiência de encapsulamento quando essa razão aumentou. As avaliações relativas à análise dimensional das micropartículas, à eficiência de encapsulamento do fármaco e à morfologia permitiram a seleção da formulação DTM-3 para os ensaios de liberação in vivo e para o estudo da estabilidade. O ensaio de liberação in vivo do fármaco associado às micropartículas demonstrou sítio-alvo preferencial no fígado, seguido pelos pulmões rins e baço. No presente estudo, as micropartículas de albumina contendo cloridrato de diltiazem foram adequadamente preparadas e orientadas satisfatoriamente para vários órgãos. Além disso, a formulação selecionada apresentou estabilidade físico-química a 4 ºC.The efficacy of a drug in a specific application requires the maintenance of appropriate drug blood level concentration during a prolonged period of time. Controlled release delivery is available for many routes of administration and offers many advantages (as microparticles and nanoparticles) over immediate release delivery. These advantages include reduced dosing frequency, better therapeutic control, fewer side effects, and, consequently, these dosage forms are well accepted by patients. Advances in polymer material science, particle engineering design, manufacture, and nanotechnology have led the way to the introduction of several marketed controlled release products and several more are in pre-clinical and clinical development. The objective of this work is to prepare and evaluate diltiazem HCl loaded albumin microparticles using a factorial design. Albumin (natural polymer) microparticles were prepared by emulsion heat-stabilization method. Selected formulations were characterized for their entrapment efficiency, particle size, surface morphology, and release behavior. Analysis of variance for entrapment efficiency indicates that entrapment efficiency is best fitted to a response surface linear model. Surface morphology was studied by scanning electron microscopy. Scanning electron microscopy of the microparticles revealed a spherical, nonporous and uniform appearance, with a smooth surface. The geometric mean diameter of the microparticles was found to be 2-9 µm, which more than 75% were below 3.5 µm and drug incorporation efficiency of 59.74 to 72.48% (w/w). In vitro release profile for formulations containing diltiazem HCl loaded BSA microparticles with heat stabilization technique shows slow controlled the release of the drug up to 24 hours. The release pattern was biphasic, characterized by an initial burst effect followed by a slow release. All selected microparticles exhibited a prolonged release for almost 24 hours. On comparing regression-coefficient (r²) values for Hixson Crowel, Higuchi and Peppas kinetic models, different batches of microparticles showed Fickian, non-Fickian, and diffusion kinetics. The release mechanism was regulated by D:P ratio. From the statistical analysis it was observed that as the drug:polymer (D:P) ratio increased, there was a significant increase in the encapsulation efficiency. Based on the particle size, entrapment efficiency and physical appearance, DTM-3 formulations were selected for in vivo release study and stability study. The in vivo result of drug loaded microparticles showed preferential drug targeting to liver followed by lungs, kidneys and spleen. Stability studies showed that maximum drug content and closest in vitro release to initial data were found in the formulation stored at 4 ºC. In present study, diltiazem HCl loaded BSA microparticles were prepared and targeted to various organs to satisfactory level and were found to be stable at 4 ºC

Incentive Stackelberg Mean-payoff Games

We introduce and study incentive equilibria for multi-player meanpayoff games. Incentive equilibria generalise well-studied solution concepts such as Nash equilibria and leader equilibria (also known as Stackelberg equilibria). Recall that a strategy profile is a Nash equilibrium if no player can improve his payoff by changing his strategy unilaterally. In the setting of incentive and leader equilibria, there is a distinguished player called the leader who can assign strategies to all other players, referred to as her followers. A strategy profile is a leader strategy profile if no player, except for the leader, can improve his payoff by changing his strategy unilaterally, and a leader equilibrium is a leader strategy profile with a maximal return for the leader. In the proposed case of incentive equilibria, the leader can additionally influence the behaviour of her followers by transferring parts of her payoff to her followers. The ability to incentivise her followers provides the leader with more freedom in selecting strategy profiles, and we show that this can indeed improve the payoff for the leader in such games. The key fundamental result of the paper is the existence of incentive equilibria in mean-payoff games. We further show that the decision problem related to constructing incentive equilibria is NP-complete. On a positive note, we show that, when the number of players is fixed, the complexity of the problem falls in the same class as two-player mean-payoff games. We also present an implementation of the proposed algorithms, and discuss experimental results that demonstrate the feasibility of the analysis of medium sized games.Comment: 15 pages, references, appendix, 5 figure