1,354,601 research outputs found
El folklore como cultura
No full textThe author refers to the difficulties surrounding the concept of folk culture. He impugns a characte rization of folklore as subject LO req uirements of form, content, learning, propagation , temporality and duration of an event. In its place, Professor Dannemann proposes the factor of communitarian reciprocal belonging as the hig hest determinat of such culture. He supports his contention by exemplifying from two of his research projects while at the same time emphasizing the force of the freedom of folk culture
Semiparametric Hidden Markov Models
No full textHidden Markov models (HMMs) are widely used for dependent data modeling. Classically, the state-dependent distributions, that is, the distribution of the observation given the hidden state, belong to some parametric family. This article proposes a semiparametric HMM for continuous observations with at least one state-dependent distribution modeled with modern nonparametric techniques, for example, nonparametric maximum likelihood estimation under shape constraints like log-concavity. The resulting model is much more flexible and avoids a model misspecification bias. Concentrating on the special case of two states, the article discusses identifiability of the model. Further, an estimation procedure for semiparametric HMMs is proposed based on the expectation-maximization algorithm, which gives also rise to model validation techniques, as demonstrated in a simulation study and an empirical illustration.Georg Lichtenberg program; Deutsche Forschungsgemeinschaft [SFB 755
Testing for two states in a hidden Markov model
No full textThe authors consider hidden Markov models (HMMs) whose latent process has m >= 2 states and whose state-dependent distributions arise from a general one-parameter family. They propose a test of the hypothesis m = 2. Their procedure is an extension to HMMs of the modified likelihood ratio statistic proposed by Chen, Chen & Kalbfleisch (2004) for testing two states in a finite mixture. The authors determine the asymptotic distribution of their test under the hypothesis m = 2 and investigate its finite-sample properties in a simulation study. Their test is based on inference for the marginal mixture distribution of the HMM. In order to illustrate the additional difficulties due to the dependence structure of the HMM, they show how to test general regular hypotheses on the marginal mixture of HMMs via a quasi-modified likelihood ratio. They also discuss two applications
Gerhard Dannemann. -The German Law of Unjustified Enrichment and Restitution, A Comparative Introduction
No full textFerrand Frédérique. Gerhard Dannemann. -The German Law of Unjustified Enrichment and Restitution, A Comparative Introduction. In: Revue internationale de droit comparé. Vol. 62 N°1,2010. pp. 174-176
Testing for two states in a hidden Markov model
No full textThe authors consider hidden Markov models (HMMs) whose latent process has m >= 2 states and whose state-dependent distributions arise from a general one-parameter family. They propose a test of the hypothesis m = 2. Their procedure is an extension to HMMs of the modified likelihood ratio statistic proposed by Chen, Chen & Kalbfleisch (2004) for testing two states in a finite mixture. The authors determine the asymptotic distribution of their test under the hypothesis m = 2 and investigate its finite-sample properties in a simulation study. Their test is based on inference for the marginal mixture distribution of the HMM. In order to illustrate the additional difficulties due to the dependence structure of the HMM, they show how to test general regular hypotheses on the marginal mixture of HMMs via a quasi-modified likelihood ratio. They also discuss two applications
Testing for two components in a switching regression model
No full textSwitching regression models form a suitable model class for regression problems with unobserved heterogeneity. A basic issue encountered in applications of switching regression models is to choose the number of states of the switching regime. Based on the modified likelihood ratio test (LRT) statistic a test for two against more states of the regime is proposed, and its asymptotic distribution is derived in the case when there is a single switching parameter. Further, it is shown that the asymptotic distribution of the test remains unchanged if the regime is Markov dependent. A simulation study illustrates the finite-sample behavior of the test. Finally, the methodology is applied to the data of a dental health trial. In this case the model selection criteria AIC and BIC favor distinct binomial regression models with switching intercepts (AIC three states, BIC two states). The modified LRT allows us to reject the null hypothesis of two states in favor of three states. (C) 2010 Elsevier B.V. All rights reserved
Manuel Teodoro Dannemann Rothstein 1932-2021
No full textEl mundo del Folklore está de luto. El 8 de abril nos dejó físicamente el Dr. Manuel Dannemann Rothstein, uno de los grandes Maestros, sino el más grande, del Folklore latinoamericano, y una figura destacada en el ámbito mundial.Académico de la Facultad de Ciencias Sociales de la Universidad de Chile y miembro conspicuo de la prestigiosa Sociedad Chilena de Historia y Geografía, director del Programa de Desarrollo de Identidades Culturales y del Seminario Interfacultades El Folclore como cultura, fue además fundador de un Museo de la Vivienda Tradicional Local, emplazado en el Bosque Santiago del Parque Metropolitano de Chile. Hoy, ante su partida, queda a las generaciones que empiezan a asomar a estos estudios la ineludible responsabilidad de nutrirse de la obra de Manuel Dannemann que, a partir de ahora, empieza a transitar sus propios caminos, iluminados por el espíritu de su autor que nos acompaña y nos guía desde la otra orilla.Fil: Palleiro, Maria Ines. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto de Filología y Literatura Hispánica "Dr. Amado Alonso"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
The likelihood ratio test for hidden Markov models in two-sample problems
No full textThe asymptotic distribution of the likelihood ratio test statistic in two-sample testing problems for hidden Markov models is derived when allowing for unequal sample sizes as well as for different families of state-dependent distributions. In both cases under regularity conditions the limit distribution is a standard chi(2)-distribution, and in particular does not depend on the ratio of the distinct sample sizes. In a simulation study, the finite sample properties are investigated, and the methodology is illustrated in an application to modeling the movement of Drosophila larvae. (C) 2007 Elsevier B.V. All rights reserved
Likelihood ratio testing for hidden markov models under non-standard conditions
No full textIn practical applications, when testing parametric restrictions for hidden Markov models (HMMs), one frequently encounters non-standard situations such as testing for zero entries in the transition matrix, one-sided tests for the parameters of the transition matrix or for the components of the stationary distribution of the underlying Markov chain, or testing boundary restrictions on the parameters of the state-dependent distributions. In this paper, we briefly discuss how the relevant asymptotic distribution theory for the likelihood ratio test (LRT) when the true parameter is on the boundary extends from the independent and identically distributed situation to HMMs. Then we concentrate on discussing a number of relevant examples. The finite-sample performance of the LRT in such situations is investigated in a simulation study. An application to series of epileptic seizure counts concludes the paper
Sabotaging Piano Concert
No full textIn this concert we explored the edge between composition and improvisation. We invited a pianist to perform a half-improvised, half-composed piece written by Teodoro Dannemann, a piece specifically written for the Sabotaging Piano and premiered at the International Conference of New Musical Expression (NIME) 2023 at Mexico City. The Sabotaging Piano is an electronic prepared piano that challenges performers through the remapping of keys to unexpected pitches. For every new performance, a new remapping pattern is given, so performers face a continuously surprising new element. The performer is provided with an expression pedal (a “sabotaging pedal”) to modulate the amount of keys that will we remapped, going from none to all of them
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