7 resultados para definition of PE

em Cochin University of Science


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Medical fields requires fast, simple and noninvasive methods of diagnostic techniques. Several methods are available and possible because of the growth of technology that provides the necessary means of collecting and processing signals. The present thesis details the work done in the field of voice signals. New methods of analysis have been developed to understand the complexity of voice signals, such as nonlinear dynamics aiming at the exploration of voice signals dynamic nature. The purpose of this thesis is to characterize complexities of pathological voice from healthy signals and to differentiate stuttering signals from healthy signals. Efficiency of various acoustic as well as non linear time series methods are analysed. Three groups of samples are used, one from healthy individuals, subjects with vocal pathologies and stuttering subjects. Individual vowels/ and a continuous speech data for the utterance of the sentence "iruvarum changatimaranu" the meaning in English is "Both are good friends" from Malayalam language are recorded using a microphone . The recorded audio are converted to digital signals and are subjected to analysis.Acoustic perturbation methods like fundamental frequency (FO), jitter, shimmer, Zero Crossing Rate(ZCR) were carried out and non linear measures like maximum lyapunov exponent(Lamda max), correlation dimension (D2), Kolmogorov exponent(K2), and a new measure of entropy viz., Permutation entropy (PE) are evaluated for all three groups of the subjects. Permutation Entropy is a nonlinear complexity measure which can efficiently distinguish regular and complex nature of any signal and extract information about the change in dynamics of the process by indicating sudden change in its value. The results shows that nonlinear dynamical methods seem to be a suitable technique for voice signal analysis, due to the chaotic component of the human voice. Permutation entropy is well suited due to its sensitivity to uncertainties, since the pathologies are characterized by an increase in the signal complexity and unpredictability. Pathological groups have higher entropy values compared to the normal group. The stuttering signals have lower entropy values compared to the normal signals.PE is effective in charaterising the level of improvement after two weeks of speech therapy in the case of stuttering subjects. PE is also effective in characterizing the dynamical difference between healthy and pathological subjects. This suggests that PE can improve and complement the recent voice analysis methods available for clinicians. The work establishes the application of the simple, inexpensive and fast algorithm of PE for diagnosis in vocal disorders and stuttering subjects.

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Timely detection of sudden change in dynamics that adversely affect the performance of systems and quality of products has great scientific relevance. This work focuses on effective detection of dynamical changes of real time signals from mechanical as well as biological systems using a fast and robust technique of permutation entropy (PE). The results are used in detecting chatter onset in machine turning and identifying vocal disorders from speech signal.Permutation Entropy is a nonlinear complexity measure which can efficiently distinguish regular and complex nature of any signal and extract information about the change in dynamics of the process by indicating sudden change in its value. Here we propose the use of permutation entropy (PE), to detect the dynamical changes in two non linear processes, turning under mechanical system and speech under biological system.Effectiveness of PE in detecting the change in dynamics in turning process from the time series generated with samples of audio and current signals is studied. Experiments are carried out on a lathe machine for sudden increase in depth of cut and continuous increase in depth of cut on mild steel work pieces keeping the speed and feed rate constant. The results are applied to detect chatter onset in machining. These results are verified using frequency spectra of the signals and the non linear measure, normalized coarse-grained information rate (NCIR).PE analysis is carried out to investigate the variation in surface texture caused by chatter on the machined work piece. Statistical parameter from the optical grey level intensity histogram of laser speckle pattern recorded using a charge coupled device (CCD) camera is used to generate the time series required for PE analysis. Standard optical roughness parameter is used to confirm the results.Application of PE in identifying the vocal disorders is studied from speech signal recorded using microphone. Here analysis is carried out using speech signals of subjects with different pathological conditions and normal subjects, and the results are used for identifying vocal disorders. Standard linear technique of FFT is used to substantiate thc results.The results of PE analysis in all three cases clearly indicate that this complexity measure is sensitive to change in regularity of a signal and hence can suitably be used for detection of dynamical changes in real world systems. This work establishes the application of the simple, inexpensive and fast algorithm of PE for the benefit of advanced manufacturing process as well as clinical diagnosis in vocal disorders.

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The present study was an attempt to analytically approach the problem of farm poverty in Kerala from an entirely different angle by incorporating an independently developed and reformulated definition of poverty line in terms of physical units of operational holdings (say, acre). The entire discussion on farm poverty emerged out of proper co-ordination of two important factors popularly considered as the distinct features of Iof marginal holdings and the unique and emirable position enjoyed by the state in terms of farm productivity. This brief analytical study on farm poverty, conducted in the light of inter regional variations in farm productivity tried to highlight various grave issues deserving thorough introspection.

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The overall focus of the thesis involves the legal protection for consumers of pharmaceutical products.The work on “Legal Protection for Consumers of Pharmaceutical Products” is undertaken to study the legal framework that is existing for this purpose and the functioning of regulating mechanism that is envisaged under it. The purpose of the study is to analyse how far these measures are effective in adequately protecting various aspects of consumer interest. Methodology adopted for the study is analytical.The present study revealed that the theory of freedom of contract is only an ideal relevant when the parties are assumed to be on equal footing.In a more complicated social and economic society, it ceased to have any relevance. Many countries in the world enacted legislations to protect the consumers of pharmaceutical products.The meaning of ‘consumers of drugs’ provided in the law is inclusive and not exhaustive one. The definition of ‘drug’ as interpreted by the courts is comprehensive enough to take in it not only medicines but also substances. The meaning of the word substances has been widened by the interpretation of the courts so as to include all the things used in treatment.The definition of the word ‘consumer’ has been liberally interpreted by the courts so as to provide protective net to a large section of the public.The studies subsequent to this report also revealed that there is a shortage of essential drugs necessary to cure local diseases like tuberculosis and malaria where as drugs containing vitamins and other combinations which are more profitable for the manufacturers are produced and marketed in abundance.The study of the provisions in this regard revealed that the duty of the drug controlling authorities is confined to scrutinize the data of the clinical test already conducted by the sponsor of the drug.Study of the clinical trial procedure under the U.S. law revealed that there is a continuous supervision over clinical trials and controls are provided on the treatment use of an investigational productStudy of the clinical trial procedure under the U.S. law revealed that there is a continuous supervision over clinical trials and controls are provided on the treatment use of an investigational product.the study of the provisions of the Drugs and Cosmetics Act and the rules framed under it revealed that the law in this regard is comprehensive to protect the consumer provided it is sufficiently supported by adequately equipped enforcement machinery.

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The study of stability problems is relevant to the study of structure of a physical system. It 1S particularly important when it is not possible to probe into its interior and obtain information on its structure by a direct method. The thesis states about stability theory that has become of dominant importance in the study of dynamical systems. and has many applications in basic fields like meteorology, oceanography, astrophysics and geophysics- to mention few of them. The definition of stability was found useful 1n many situations, but inadequate in many others so that a host of other important concepts have been introduced in past many years which are more or less related to the first definition and to the common sense meaning of stability. In recent years the theoretical developments in the studies of instabilities and turbulence have been as profound as the developments in experimental methods. The study here Points to a new direction for stability studies based on Lagrangian formulation instead of the Hamiltonian formulation used by other authors.

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Theoretically speaking, property is extension of the personality of the individual. It serves the purpose of satisfying the self of the individual in the society. Various theories have been attempted to explain its origin and development. However, it is the socialist theory of property which finds acceptance in many societies today. A proper definition of the concept of property has notbeen given in the statutes governing protection of property or in the Indian Constitution. While deciding cases under the Indian Penal Code, the courts have however, been interpreting the term 'property' in a manner facilitating its accommodation within the contours of the socialist theory of property, though there was no attempt for any formal theorization. An examination of the decisions under the Penal Code provisions and Constituent Assembly Debates has reinforced the above view that our courts as well as legislature have adopted the socialist concept of property. Because of the importance of the theory of property in the general scheme of this study, it was thought appropriate toinclude a chapter on the theory of property as reflected in our constitution.

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This thesis is an outcome of the investigations carried out on the development of an Artificial Neural Network (ANN) model to implement 2-D DFT at high speed. A new definition of 2-D DFT relation is presented. This new definition enables DFT computation organized in stages involving only real addition except at the final stage of computation. The number of stages is always fixed at 4. Two different strategies are proposed. 1) A visual representation of 2-D DFT coefficients. 2) A neural network approach. The visual representation scheme can be used to compute, analyze and manipulate 2D signals such as images in the frequency domain in terms of symbols derived from 2x2 DFT. This, in turn, can be represented in terms of real data. This approach can help analyze signals in the frequency domain even without computing the DFT coefficients. A hierarchical neural network model is developed to implement 2-D DFT. Presently, this model is capable of implementing 2-D DFT for a particular order N such that ((N))4 = 2. The model can be developed into one that can implement the 2-D DFT for any order N upto a set maximum limited by the hardware constraints. The reported method shows a potential in implementing the 2-D DF T in hardware as a VLSI / ASIC