916 resultados para Measure of adaptability
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A measure of association is row-size invariant if it is unaffected by the multiplication of all entries in a row of a cross-classification table by a same positive number. It is class-size invariant if it is unaffected by the multiplication of all entries in a class (i.e., a row or a column). We prove that every class-size invariant measure of association as-signs to each m x n cross-classification table a number which depends only on the cross-product ratios of its 2 x 2 subtables. We propose a monotonicity axiom requiring that the degree of association should increase after shifting mass from cells of a table where this mass is below its expected value to cells where it is above .provided that total mass in each class remains constant. We prove that no continuous row-size invariant measure of association is monotonic if m ≥ 4. Keywords: association, contingency tables, margin-free measures, size invariance, monotonicity, transfer principle.
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We estimate the volatility of plant–level idiosyncratic shocks in the U.S. manufacturing sector. Our measure of volatility is the variation in Revenue Total Factor Productivity which is not explained by either industry– or economy–wide factors, or by establishments’ characteristics. Consistent with previous studies, we find that idiosyncratic shocks are much larger than aggregate random disturbances, accounting for about 80% of the overall uncertainty faced by plants. The extent of cross–sectoral variation in the volatility of shocks is remarkable. Plants in the most volatile sector are subject to about six times as much idiosyncratic uncertainty as plants in the least volatile. We provide evidence suggesting that idiosyncratic risk is higher in industries where the extent of creative destruction is likely to be greater.
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Essai présenté à la Faculté des arts et des sciences en vue de l’obtention du grade de Doctorat en psychologie option psychologie clinique
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Note de l'éditeur : This article may not exactly replicate the final version published in the APA journal. It is not the copy of record. / Cet article ne constitue pas la version officielle, et peut différer de la version publiée dans la revue.
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Introduction Provoked vestibulodynia (PVD) is suspected to be the most frequent cause of vulvodynia in premenopausal women. Based on the onset of PVD relative to the start of sexual experience, PVD can be divided into primary (PVD1) and secondary PVD (PVD2). Studies comparing these PVD subgroups are inconclusive as to whether differences exist in sexual and psychosocial functioning. Aim The aim of this study was to compare the pain, sexual and psychosocial functioning of a large clinical and community-based sample of premenopausal women with PVD1 and PVD2. Methods A total of 269 women (n = 94 PVD1; n = 175 PVD2) completed measures on sociodemographics, pain, sexual, and psychosocial functioning. Main Outcome Measures Dependent variables were the 0–10 pain numerical rating scale, McGill–Melzack Pain Questionnaire, Female Sexual Function Index, Global Measure of Sexual Satisfaction, Beck Depression Inventory-II, Painful Intercourse Self-Efficacy Scale, Pain Catastrophizing Scale, State-Trait Anxiety Inventory Trait Subscale, Ambivalence over Emotional Expression Questionnaire, Hurlbert Index of Sexual Assertiveness, Experiences in Close Relationships Scale—Revised, and Dyadic Adjustment Scale-Revised. Results At first sexual relationship, women with PVD2 were significantly younger than women with PVD1 (P < 0.01). The average relationship duration was significantly longer in women with PVD2 compared with women with PVD1 (P < 0.01). Although women with PVD1 described a significantly longer duration of pain compared with women with PVD2 (P < 0.01), no significant subtype differences were found in pain intensity during intercourse. When controlling for the sociodemographics mentioned earlier, no significant differences were found in sexual, psychological, and relational functioning between the PVD subgroups. Nevertheless, on average, both groups were in the clinical range of sexual dysfunction and reported impaired psychological functioning. Conclusions The findings show that there are no significant differences in the sexual and psychosocial profiles of women with PVD1 and PVD2. Results suggest that similar psychosocial and sex therapy interventions should be offered to both subgroups of PVD.
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Note de l'éditeur : This article may not exactly replicate the final version published in the journal. It is not the copy of record. / Cet article ne constitue pas la version officielle, et peut différer de la version publiée dans la revue.
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Introduction Provoked vestibulodynia (PVD) is a prevalent genital pain syndrome that has been assumed to be chronic, with little spontaneous remission. Despite this assumption, there is a dearth of empirical evidence regarding the progression of PVD in a natural setting. Although many treatments are available, there is no single treatment that has demonstrated efficacy above others. Aims The aims of this secondary analysis of a prospective study were to (i) assess changes over a 2-year period in pain, depressive symptoms, and sexual outcomes in women with PVD; and (ii) examine changes based on treatment(s) type. Methods Participants completed questionnaire packages at Time 1 and a follow-up package 2 years later. Main Outcome Measures Visual analog scale of genital pain, Global Measure of Sexual Satisfaction, Female Sexual Function Index, Beck Depression Inventory, Dyadic Adjustment Scale, and sexual intercourse attempts over the past month. Results Two hundred thirty-nine women with PVD completed both time one and two questionnaires. For the sample as a whole, there was significant improvement over 2 years on pain ratings, sexual satisfaction, sexual function, and depressive symptoms. The most commonly received treatments were physical therapy, sex/psychotherapy, and medical treatment, although 41.0% did not undergo any treatment. Women receiving no treatment also improved significantly on pain ratings. No single treatment type predicted better outcome for any variable except depressive symptoms, in which women who underwent surgery were more likely to improve. Discussion These results suggest that PVD may significantly reduce in severity over time. Participants demonstrated clinically significant pain improvement, even when they did not receive treatment. Furthermore, the only single treatment type predicting better outcomes was surgery, and only for depressive symptoms, accounting for only 2.3% of the variance. These data do not demonstrate the superiority of any one treatment and underscore the need to have control groups in PVD treatment trials, otherwise improvements may simply be the result of natural progression.
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Introduction Entry dyspareunia is a sexual health concern which affects about 21% of women in the general population. Characterized by pain provoked during vaginal penetration, introital dyspareunia has been shown by controlled studies to have a negative impact on the psychological well-being, sexual function, sexual satisfaction, and quality of life of afflicted women. Many cognitive and affective variables may influence the experience of pain and associated psychosexual problems. However, the role of the partner's cognitive responses has been studied very little. Aim The aim of the present study was to examine the associations between partners' catastrophizing and their perceptions of women's self-efficacy at managing pain on one side and women's pain intensity, sexual function, and sexual satisfaction on the other. Methods One hundred seventy-nine heterosexual couples (mean age for women = 31, SD = 10.0; mean age for men = 33, SD = 10.6) in which the woman suffered from entry dyspareunia participated in the study. Both partners completed quantitative measures. Women completed the Pain Catastrophizing Scale and the Painful Intercourse Self-Efficacy Scale. Men completed the significant-other versions of these measures. Main Outcome Measures Dependent measures were women's responses to (i) the Pain Numeric Visual Analog Scale; (ii) the Female Sexual Function Index; and (iii) the Global Measure of Sexual Satisfaction scale. Results Controlled for women's pain catastrophizing and self-efficacy, results indicate that higher levels of partner-perceived self-efficacy and lower levels of partner catastrophizing are associated with decreased pain intensity in women with entry dyspareunia, although only partner catastrophizing contributed unique variance. Partner-perceived self-efficacy and catastrophizing were not significantly associated with sexual function or satisfaction in women. Conclusions The findings suggest that partners' cognitive responses may influence the experience of entry dyspareunia for women, pointing toward the importance of considering the partner when treating this sexual health problem.
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The present study focuses attention on defining certain measures of income inequality for the truncated distributions and characterization of probability distributions using the functional form of these measures, extension of some measures of inequality and stability to higher dimensions, characterization of bivariate models using the above concepts and estimation of some measures of inequality using the Bayesian techniques. The thesis defines certain measures of income inequality for the truncated distributions and studies the effect of truncation upon these measures. An important measure used in Reliability theory, to measure the stability of the component is the residual entropy function. This concept can advantageously used as a measure of inequality of truncated distributions. The geometric mean comes up as handy tool in the measurement of income inequality. The geometric vitality function being the geometric mean of the truncated random variable can be advantageously utilized to measure inequality of the truncated distributions. The study includes problem of estimation of the Lorenz curve, Gini-index and variance of logarithms for the Pareto distribution using Bayesian techniques.
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The present study on the characterization of probability distributions using the residual entropy function. The concept of entropy is extensively used in literature as a quantitative measure of uncertainty associated with a random phenomenon. The commonly used life time models in reliability Theory are exponential distribution, Pareto distribution, Beta distribution, Weibull distribution and gamma distribution. Several characterization theorems are obtained for the above models using reliability concepts such as failure rate, mean residual life function, vitality function, variance residual life function etc. Most of the works on characterization of distributions in the reliability context centers around the failure rate or the residual life function. The important aspect of interest in the study of entropy is that of locating distributions for which the shannon’s entropy is maximum subject to certain restrictions on the underlying random variable. The geometric vitality function and examine its properties. It is established that the geometric vitality function determines the distribution uniquely. The problem of averaging the residual entropy function is examined, and also the truncated form version of entropies of higher order are defined. In this study it is established that the residual entropy function determines the distribution uniquely and that the constancy of the same is characteristics to the geometric distribution
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In this thesis, the concept of reversed lack of memory property and its generalizations is studied.We we generalize this property which involves operations different than the ”addition”. In particular an associative, binary operator ” * ” is considered. The univariate reversed lack of memory property is generalized using the binary operator and a class of probability distributions which include Type 3 extreme value, power function, reflected Weibull and negative Pareto distributions are characterized (Asha and Rejeesh (2009)). We also define the almost reversed lack of memory property and considered the distributions with reversed periodic hazard rate under the binary operation. Further, we give a bivariate extension of the generalized reversed lack of memory property and characterize a class of bivariate distributions which include the characterized extension (CE) model of Roy (2002a) apart from the bivariate reflected Weibull and power function distributions. We proved the equality of local proportionality of the reversed hazard rate and generalized reversed lack of memory property. Study of uncertainty is a subject of interest common to reliability, survival analysis, actuary, economics, business and many other fields. However, in many realistic situations, uncertainty is not necessarily related to the future but can also refer to the past. Recently, Di Crescenzo and Longobardi (2009) introduced a new measure of information called dynamic cumulative entropy. Dynamic cumulative entropy is suitable to measure information when uncertainty is related to the past, a dual concept of the cumulative residual entropy which relates to uncertainty of the future lifetime of a system. We redefine this measure in the whole real line and study its properties. We also discuss the implications of generalized reversed lack of memory property on dynamic cumulative entropy and past entropy.In this study, we extend the idea of reversed lack of memory property to the discrete set up. Here we investigate the discrete class of distributions characterized by the discrete reversed lack of memory property. The concept is extended to the bivariate case and bivariate distributions characterized by this property are also presented. The implication of this property on discrete reversed hazard rate, mean past life, and discrete past entropy are also investigated.
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Brasses are widely used as constructional materials in marine environment due to their anticorrosive,antifouling and mechanical properties.However, its resistance to corrosion and fouling may vary according to local marine environmental condition and the seasons.The dezincification of brass is one of the forms of selective corrosion which has attracted the attention of researchers for the last two decades.Many of the dezincification mechanistic studies have been performed in noncomplex media and hence their conclusions cannot be extended to esturine water,which is of great significance since brass is extensively used in marine environment.Inhibited α brasses are largely immune to dezincication and the effect of tin and arsenic addition to α/beta brasses is not so reliable in controlling the dezincification. There have been many cases of dezincification in duplex brasses in both freshwater and seawater.Though there is some protection methods such as inhibitors,electro deposition and electro polymerization,there is no reliable method of inhibiting the dezincification of two-phase brass.Organic coatings are effectively used for the protection metals due to their capacity to act a physical barrieer between the metal surface and corrosive environment.Hence,pure epoxy coating is selected for this as it has antocorrosiion effect on brass.The dezincification behaviour of brass of the present study has been highlighted in terms of corrosion rate,weight gain/loss,corrosion current and polarization resistence,open circuit potential,dezincification factor. The marine fouling as biomass on brass was assessed and presented in this thesis, The physicochemical properties of estuarine water were correlated with corrosion behaviour of brass.The deterioration of the brass subjected to the effect of estuarine water was also investigated as a measure of loss in mechanical properties such as tensile strength,yield strength,percntage elongation and percentage reduction in area.To validate dezincification data,visual observation,spot analysis,surface morphology before and after removal of corrosion products and corrosion product analysis were performed.The dezincification behavior of epoxy coated brass of the present study has beenhighlighted in terms of corrosion rate ,weight gain/loss,corrosion current and polarization resistance,open circuit potential.dezincification factor.The marine fouling as biomass on epoxy coated brass subjeted to the effect of estuarine water was also investigated as ameasure of loss in mechanical properties such as tensile strength,percentage elongation and percentage reduction in area.The results of dezincification behavior of brass and epoxy coated brass in Cochin estuary water has been presented and discussed.Attempt has been made to correlate the dezincification behavior of brass with epoxy coated brass.
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A simple, effective and inexpensive fiber optic sensor for investigating the setting characteristics of various grades of cement is described. A finite length of unsheathed multimode optical fiber laid inside the cement mix, is subjected to stress during the setting process. The microbends created on the fiber due to this stress directly influence the intensity of light propagating through the fiber. Continuous monitoring of such variations in the light output transmitted through the fiber gives a clear measure of the setting characteristics of the cement mix, thus providing a simple and elegant technique of great practical importance in the field of civil engineering. The smart fiber optic sensor described above can be incorporated into a building during the construction process itself so that continuous monitoring of the deterioration process for the entire life time of the building can be carried out.
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We have numerically studied the behavior of a two-mode Nd-YAG laser with an intracavity KTP crystal. It is found that when the parameter, which is a measure of the relative orientations of the KTP crystal with respect to the Nd-YAG crystal, is varied continuously, the output intensity fluctuations change from chaotic to stable behavior through a sequence of reverse period doubling bifurcations. The graph of the intensity in the X-polarized mode against that in the Y-polarized mode shows a complex pattern in the chaotic regime. The Lyapunov exponent is calculated for the chaotic and periodic regions.
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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.