On the convergence of two sequential Monte Carlo methods for maximum a posteriori sequence estimation and stochastic global optimization

This paper addresses the problem of maximum a posteriori (MAP) sequence estimation in general state-space models. We consider two algorithms based on the sequential Monte Carlo (SMC) methodology (also known as particle filtering). We prove that they produce approximations of the MAP estimator and that they converge almost surely. We also derive a lower bound for the number of particles that are needed to achieve a given approximation accuracy. In the last part of the paper, we investigate the application of particle filtering and MAP estimation to the global optimization of a class of (possibly non-convex and possibly non-differentiable) cost functions. In particular, we show how to convert the cost-minimization problem into one of MAP sequence estimation for a state-space model that is “matched” to the cost of interest. We provide examples that illustrate the application of the methodology as well as numerical results.     

Confidence intervals for the ratio of two variances

In this paper we consider confidence intervals for the ratio of two population variances. We propose a confidence interval for the ratio of two variances based on the t-statistic by deriving its Edgeworth expansion and considering Hall's and Johnson's transformations. Then, we consider the coverage accuracy of suggested intervals and intervals based on the F-statistic for some distributions.     

Applications of Marshall–Olkin Fréchet Distribution

In this article, we consider the applications of Marshall–Olkin Fréchet distribution. The reliability of a system when both stress and strength follows the new distribution is discussed and related characteristics are computed for simulated data. The model is applied to a real data set on failure times of air-conditioning systems in jet planes and reliability is estimated. We also develop acceptance sampling plan for the acceptance of a lot whose lifetime follows this distribution. Four different autoregressive time series models of order 1 are developed with minification structure as well as max-min structure having these stationary marginal distributions. Some properties of the models are also established.     

A new family of lifetime models

We introduce a new family of distributions by adding a parameter to the Marshall–Olkin family of distributions. Some properties of the new family of distributions are derived. A particular case of the family, a three-parameter generalization of the exponential distribution, is given special attention. The shape properties, moments, distributions of the order statistics, entropies and estimation procedures are derived. An application to a real data set is discussed.     

What’s off-centre of empire? Introduction to the special issue

ABSTRACT

In this Introduction, we discuss the aims of this publication along with guidelines to locate and connect the essays part of the edited volume. We start by highlighting the original contribution of our intervention in terms of what off-centring empire offers in relation to scholarship that de-centres empire. To us, this means to look at the processes, dynamics, and movements that connect empire (as a centre of power) to its peripheries (as a site of difference, struggles, and resistance). To be sure, attempts to off-centre and de-centre empire are related, relational, and they both commit to the project of challenging the centrality of empire, to confronting its lasting legacies and normative powers. Yet to off-centre, as we argue, is to focus on the electrifying force-field generated by the poles of imperial power, rather than oppose centre and peripheries to subvert their relationship. Our aim is to reveal the complex ways centre and periphery connect and distance with the aim to highlight emerging modes of counter-imperial practice. Further, this introduction serves as the opportunity to discuss the structure of the SI and its three main sections – Public Memory, Orientations, and More-than-human. Here we reflect upon how each essay brings to the fore a unique way to off-centre empire, and thus provide examples that may inspire future research. Finally, we highlight how conversations emerging from individual essays can be assembled and read into threads, pointing to multiple ways in which we seek to off-centre empire through empirical research.     

Post-communist lavender menace: lesbians in mainstream East European film

The article examines four films-Károly Makk's Egymásra nézve (Another Way, Hungary, 1982), Maja Weiss's Varuh meje (Guardian of the Frontier, Slovenia 2002), Dalibor Matani?'s Fine mrtve djevojke (Fine Dead Girls, Croatia, 2002), and Dragan Marinkovi?'s Di?i duboko (Take a Deep Breath, Serbia, 2004)-as post-communist or dissident national allegories. In all of these films by straight directors the lesbians represent a metaphorical threat to the hetero/sexist national order, but they are unfortunately little more than simulacra. They can be emotionally real (and fun for the straight male audience to ogle), but that ultimately works against them, because instead of representing real lesbian communities, they still have to affirm the stereotype of tragic lesbian destiny straight audiences find comforting.     

Foreign policy priorities and ethnic return migration policies: group-level variation in Greece and Serbia

ABSTRACT

Why do ethnoculturally defined states pursue favourable policies to integrate some returnees from their historical diasporas while neglecting or excluding others? We study this question by looking at members of two historical diasporas that, in the 1990s, returned to their respective ethnic homelands, Greece and Serbia, but were not treated uniformly by their respective governments. Utilising a wide range of primary sources, we consider evidence for a number of plausible explanations for such policy variation, including the economic profile of an ethnic returnee group, its status in internal ethnic hierarchies, its lobbying power, and dynamics of party politics. We find, instead, that the observed variation is best explained by the role that each particular group played in the ruling elites’ ex ante foreign policy objectives. Elites discouraged the repatriation of co-ethnics from parts of the world they still had claims over, by pursuing unfavourable repatriation policies. Conversely, absent a revisionist claim, states adopted favourable repatriation policies to encourage their repatriation and facilitate their integration upon return. Methodologically, the article illustrates the importance of focused comparisons across dyads of states and particular sub-diaspora groups.