Beyond Binomial and Negative Binomial: Adaptation in Bernoulli Parameter Estimation

Estimating the parameter of a Bernoulli process arises in many applications, including photon-efficient active imaging where each illumination period is regarded as a single Bernoulli trial. Motivated by acquisition efficiency when multiple Bernoulli processes are of interest, we formulate the allocation of trials under a constraint on the mean as an optimal resource allocation problem. An oracle-aided trial allocation demonstrates that there can be a significant advantage from varying the allocation for different processes and inspires a simple trial allocation gain quantity. Motivated by realizing this gain without an oracle, we present a trellis-based framework for representing and optimizing stopping rules. Considering the convenient case of Beta priors, three implementable stopping rules with similar performances are explored, and the simplest of these is shown to asymptotically achieve the oracle-aided trial allocation. These approaches are further extended to estimating functions of a Bernoulli parameter. In simulations inspired by realistic active imaging scenarios, we demonstrate significant mean-squared error improvements: up to 4.36 dB for the estimation of p and up to 1.80 dB for the estimation of log p.Comment: 13 pages, 16 figure

Identifying Clusters of Complex Urban–Rural Issues as Part of Policy Making Process Using a Network Analysis Approach: A Case Study in Bahía de Los Ángeles, Mexico

Improving human settlements diagnosis is a key factor in effective urban planning and the design of efficient policy making. In this paper, we illustrate how network theory concepts can be applied to reveal the topological structure of functional relationships in a network of heterogeneous urban–rural issues. This mapping is done using clustering algorithms and centrality value techniques. By analyzing emergent groups of urban–rural related issues, our methodology was applied to a rural community, considering in this exercise environmental matters and real estate interests as a way to better understand the structure of salient issues in the context of its urban development program design. Results show clusters that arrange themselves not by an obvious similarity in their constituent components, but by relations observed in urban–rural settings that hint on the issues that the urban development program must focus. Due to its complex nature, the classification of these emerging clusters and how they must be treated in traditional planning instruments is a new challenge that this novel methodology reveals

Modelling the Interaction Levels in HCI Using an Intelligent Hybrid System with Interactive Agents: A Case Study of an Interactive Museum Exhibition Module in Mexico

Technology has become a necessity in our everyday lives and essential for completing activities we typically take for granted; technologies can assist us by completing set tasks or achieving desired goals with optimal affect and in the most efficient way, thereby improving our interactive experiences. This paper presents research that explores the representation of user interaction levels using an intelligent hybrid system approach with agents. We evaluate interaction levels of Human-Computer Interaction (HCI) with the aim of enhancing user experiences. We consider the description of interaction levels using an intelligent hybrid system to provide a decision-making system to an agent that evaluates interaction levels when using interactive modules of a museum exhibition. The agents represent a high-level abstraction of the system, where communication takes place between the user, the exhibition and the environment. In this paper, we provide a means to measure the interaction levels and natural behaviour of users, based on museum user-exhibition interaction. We consider that, by analysing user interaction in a museum, we can help to design better ways to interact with exhibition modules according to the properties and behaviour of the users. An interaction-evaluator agent is proposed to achieve the most suitable representation of the interaction levels with the aim of improving user interactions to offer the most appropriate directions, services, content and information, thereby improving the quality of interaction experienced between the user-agent and exhibition-agent

Neuroimagen del linfoma primario del sistema nervioso central en pacientes inmunodeprimidos

ResumenObjetivosEl linfoma primario del sistema nervioso central (LPSNC) es una entidad rara con un pronóstico fatal. Dado el aumento en el número de casos con inmunosupresión adquirida, nuestros objetivos son estudiar las características epidemiológicas y neurorradiológicas de aquellos pacientes inmunodeprimidos con diagnóstico de LPSNC con afectación cerebral e investigar si existen diferencias entre los pacientes con el virus de la inmunodeficiencia humana (VIH) positivo y negativo.Materiales y métodosSe realizó un estudio descriptivo y retrospectivo de los pacientes inmunodeprimidos con afectación cerebral por LPSNC, diagnosticados durante los últimos 13 años en 2 hospitales de referencia. Se evaluaron múltiples variables. El nivel de significación estadística utilizado fue p<0,05.ResultadosEl grupo VIH-positivo tenía una media de edad de 36,82±5,4 años, frente a los 55,60 ± 21,43 años de los pacientes VIH-negativo (p<0,022). Los pacientes VIH-positivo tuvieron una media de 1,27 ± 0,65 lesiones por paciente, mientras que en el grupo VIH-negativo fue de 2,60 ± 1,78 (p<0,039). El 18,2% (n=2) del grupo VIH-positivo y el 80% (n=8) del grupo VIH-negativo presentaron lesiones homogéneas (p<0,005). Ningún paciente VIH-positivo tuvo afectación del cuerpo calloso, pero el grupo VIH-negativo presentó un 50% (n=5) de afectación (p<0,012).ConclusionesEl LPSNC en pacientes inmunodeprimidos puede presentar múltiples características en las imágenes. Existen diferencias entre los pacientes VIH positivo y negativo, por lo que es importante reconocerlas para establecer un manejo y tratamiento diferente entre ambos grupos.AbstractPurposesPrimary central nervous system lymphoma (PCNSL) is a rare tumour with poor prognosis. Due to the increased number of patients with acquired immunodeficiency, our purposes are to describe epidemiological and imaging findings in immunodeficient patients with PCNSL of the brain and to study the differences between HIV-positive and HIV-negative patients with PCNSL.Materials and methodsA retrospective, descriptive study was performed with immunodeficient patients diagnosed of PCNSL of the brain during the last 13 years in two reference hospitals. Twenty-one patients fulfilled the inclusion criteria. Multiple variables were evaluated. Significance was defined as p<0.05.ResultsHIV-positive group was a mean age of 36,82±5,4 years and the mean age in HIV-negative group was 55,60±21,43 years (p<0,022). The mean number of lesions was 1,27±0,65 in HIV-positive group and 2,60±1,78 in HIV-negative group (p<0,039). The lesions were homogeneous in 18,2% (n=2) HIV-positive group and 80% (n=8) in HIV-negative group (p<0,005). No HIV-positive patient and 50% (n=5) of HIV-negative patients showed corpus callosum involvement (p<0,012).ConclusionsPCNSL in immunodeficient patients is associated with a large spectrum of radiological findings. There were differences between HIV-positive and HIV-negative patients, is important recognize these differences as the therapeutic management of these two groups vary

Towards Team Formation Using Belbin Role Types and a Social Networks Analysis Approach

Problems relating to team formation is common across many industrial sectors, including education, sport and general business. For Team Leaders, team member selection can be a critical challenge due to the complexity in creating a well-balanced productive unit. It is beyond manual implementation to build near optimal teams as pools of employees grow. One of the essential skills of individuals is the ability to work in a team, and it takes on greater importance in engineering workgroups, where each member must know how to collaborate with their colleagues. In this paper, we use the combination of the Belbin roles and the social network analysis approach to find the possible members of a team. We present a case study based on an undergraduate course in computer engineering, we apply the Belbin test to each student, and each student expresses his preferences to work with his classmates. With this data, similarity patterns were searched within a social network using network analysis algorithms. We compare the results of the network analysis with the groups formed by a teacher. Finally, we discuss the advantages and disadvantages of project teams, from the proposed approach

Human noise blindness drives suboptimal cognitive inference

Humans typically make near-optimal sensorimotor judgements but show systematic biases when making more cognitive judgements. Here we test the hypothesis that, while humans are sensitive to the noise present during early sensory encoding, the “optimality gap” arises because they are blind to noise introduced by later cognitive integration of variable or discordant pieces of information. In six psychophysical experiments, human observers judged the average orientation of an array of contrast gratings. We varied the stimulus contrast (encoding noise) and orientation variability (integration noise) of the array. Participants adapted near-optimally to changes in encoding noise, but, under increased integration noise, displayed a range of suboptimal behaviours: they ignored stimulus base rates, reported excessive confidence in their choices, and refrained from opting out of objectively difficult trials. These overconfident behaviours were captured by a Bayesian model blind to integration noise. Our study provides a computationally grounded explanation of human suboptimal cognitive inference

Phase relations in the Cabeza de Araya cordierite monzogranite, Iberian Massif : implications for the formation of cordierite in a crystal mush

Experimental investigations and thermodynamic calculations of the phase relations of a cordierite-rich monzogranite from the Cabeza de Araya batholith (Cáceres, Spain) have been performed to understand the formation of cordierite. The experiments failed to crystallize cordierite in the pressure range 200-600MPa, in the temperature range 700-975ºC and for different water activities (melt water contents between 2 and 6 wt.%). In contrast, clinopyroxene and orthopyroxene (absent in the natural mineral rock assemblage), together with biotite, were observed as ferromagnesian assemblage in a wide range of experimental conditions. Thermodynamic calculations, using the software PERPLE_X, describe the formation of cordierite only at 200 and 400MPa and very low water contents, and the amount of cordierite formed in the models is always below 3.5 vol.%. The results indicate that cordierite is not in equilibrium with the bulk rock compositions. The most probable explanation was that cordierite nucleated and crystallized from a melt that is not in equilibrium with part of the mineral assemblage present in the magma. This "non-reactive" mineral assemblage was mainly composed of plagioclase. The silicate melts from which cordierite crystallized was more Al-rich and K-rich than the silicate melt composition in equilibrium with the bulk composition. One possible process for the high Al content of the silicate melt is related to assimilation and partial melting of Al-rich metasediments. An exo-perictetic reaction is assumed to account for both textural and geochemical observations. On the other hand, hybridization processes typical for calc-alkaline series can also explain the high proportions of "non-reactive" minerals observed in relatively high temperature magmas. This study clearly demonstrates that silicate melts in a crystal mush can depart significantly from the composition of melt that should be in equilibrium with the bulk solid assemblage

Introduction: Covid-19 and the conditions and struggles of agrarian classes of labour

Abstract: Covid‐19 generated a crisis in capitalism, but not of capitalism. Capitalism reproduces itself in crisis and in ways that have significant but uneven impacts on the conditions and struggles of agrarian classes of labour. This article explores preliminary studies of how Covid‐19 has affected agrarian social formations in Africa, Asia and Latin America and the farmers, petty commodity producers, labourers and agribusinesses who populate them. It considers some of the implications for wage‐labour, agriculture, accumulation and social reproduction including care work. And it briefly considers Covid‐19's political impacts—in terms of the role of the state and possibilities for challenging capitalism, its violence and its ecological crisis

270-km ultralong raman fiber laser

We analyze the physical mechanisms limiting optical fiber resonator length and report on the longest ever laser cavity, reaching 270 km, which shows a clearly resolvable mode structure with a width of ~120??Hz and peak separation of ~380Hz in the radio-frequency spectrum