Cross-Guided Clustering: Transfer of Relevant Supervision across Tasks

Lack of supervision in clustering algorithms often leads to clusters that are not useful or interesting to human reviewers. We investigate if supervision can be automatically transferred for clustering a target task, by providing a relevant supervised partitioning of a dataset from a different source task. The target clustering is made more meaningful for the human user by trading-off intrinsic clustering goodness on the target task for alignment with relevant supervised partitions in the source task, wherever possible. We propose a cross-guided clustering algorithm that builds on traditional k-means by aligning the target clusters with source partitions. The alignment process makes use of a cross-task similarity measure that discovers hidden relationships across tasks. When the source and target tasks correspond to different domains with potentially different vocabularies, we propose a projection approach using pivot vocabularies for the cross-domain similarity measure. Using multiple real-world and synthetic datasets, we show that our approach improves clustering accuracy significantly over traditional k-means and state-of-the-art semi-supervised clustering baselines, over a wide range of data characteristics and parameter settings.

Secure Compute-and-Forward in a Bidirectional Relay

We consider the basic bidirectional relaying problem, in which two users in a wireless network wish to exchange messages through an intermediate relay node. In the compute-and-forward strategy, the relay computes a function of the two messages using the naturally occurring sum of symbols simultaneously transmitted by user nodes in a Gaussian multiple-access channel (MAC), and the computed function value is forwarded to the user nodes in an ensuing broadcast phase. In this paper, we study the problem under an additional security constraint, which requires that each user's message be kept secure from the relay. We consider two types of security constraints: 1) perfect secrecy, in which the MAC channel output seen by the relay is independent of each user's message and 2) strong secrecy, which is a form of asymptotic independence. We propose a coding scheme based on nested lattices, the main feature of which is that given a pair of nested lattices that satisfy certain goodness properties, we can explicitly specify probability distributions for randomization at the encoders to achieve the desired security criteria. In particular, our coding scheme guarantees perfect or strong secrecy even in the absence of channel noise. The noise in the channel only affects reliability of computation at the relay, and for Gaussian noise, we derive achievable rates for reliable and secure computation. We also present an application of our methods to the multihop line network in which a source needs to transmit messages to a destination through a series of intermediate relays.

Zero-Crossings Based Spectrum Sensing Under Noise Uncertainties

In this work, the hypothesis testing problem of spectrum sensing in a cognitive radio is formulated as a Goodness-of-fit test against the general class of noise distributions used in most communications-related applications. A simple, general, and powerful spectrum sensing technique based on the number of weighted zero-crossings in the observations is proposed. For the cases of uniform and exponential weights, an expression for computing the near-optimal detection threshold that meets a given false alarm probability constraint is obtained. The proposed detector is shown to be robust to two commonly encountered types of noise uncertainties, namely, the noise model uncertainty, where the PDF of the noise process is not completely known, and the noise parameter uncertainty, where the parameters associated with the noise PDF are either partially or completely unknown. Simulation results validate our analysis, and illustrate the performance benefits of the proposed technique relative to existing methods, especially in the low SNR regime and in the presence of noise uncertainties.

Reflexiones sobre el método moral en persona humana

Siguiendo a Gaudium et spes (51.3), la declaración Persona humana reafirma que la bondad moral de las conductas sexuales depende de “criterios objetivos tomados de la naturaleza de la persona y de sus actos” (PH 5.4). Esto no es expresión de un objetivismo naturalista, sino que surge del respeto de la “verdadera dignidad humana” y del sentido de su sexualidad. Estas afirmaciones deben ser comprendidas en el marco de la ética de la virtud, según la cual la razón práctica descubre naturalmente los bienes humanos y debidos, los fines virtuosos, en las inclinaciones naturales. A partir de ello es posible afirmar la existencia de conductas que contradicen dichas finalidades por su mismo objeto, aunque ello no exime de la necesidad de considerar los contextos a partir de los cuales las mismas se definen en su genus moris. Aplicando estos principios al ámbito de la sexualidad, se debe afirmar que el recto ejercicio de la misma tiene una referencia intrínseca y necesaria al matrimonio, aunque al mismo tiempo es preciso reconocer un cierto grado de tensión entre el orden de la castidad y el orden jurídico positivo. Estas consideraciones muestran que, precisamente por coherencia con la doctrina de la virtud y de los absolutos morales, es preciso que la teología moral evite la tentación del deductivismo, y se comprometa en un trabajo de refinamiento de las tipologías con mayor atención a los casos concretos. De este modo, podrá responder más adecuadamente al desafío de un contexto social en constante evolución. Con este artículo, el autor aporta precisiones para expresar mejor lo expuesto en dos artículos anteriores: “¿Relaciones prematrimoniales en «situaciones-límite »?”, Teología 83 (2004), y “El teleologismo después de la Veritatis Splendor”, Moralia 97 (2003).

El optimismo metafísico en la escatología de San Ireneo

Resumen: Mucho antes de que San Agustín y Santo Tomás afirmaran que las cosas son buenas por el mero hecho de ser, ya en el siglo II de nuestra era Ireneo expresaba su confianza en la bondad fundamental de la materia. En los últimos seis capítulos del Adversus haereses (V, 31-36), el Obispo de Lyon plantea una verdadera teología de la historia que tiene como centro al hombre plasmado por Dios y llamado a su plenificación definitiva en la temporalidad y en el mismo mundo que lo vio caer. Al describir este tramo final y decisivo de la experiencia humana en la historia, nuestro autor nos revela su peculiar concepción del tiempo a la par que despliega un realismo escatológico totalmente opuesto al gnosticismo espiritualista de la época, que consideraba todo lo material como proveniente del error y la defección. A su vez, esta concepción de Ireneo supera tanto a los milenarismos ingenuos de su tiempo como a las utopías posteriores, en que el realismo escatológico es trocado en escatologismo radical. Se trata, en definitiva, de un optimismo metafísico propio de la visión cristiana que resultó novedoso para el ambiente espiritual de la época en que se gestó y que alienta a una prometedora relación del hombre con la naturaleza, ya sea desde la perspectiva del trabajo humano como fuerza transformadora de la misma, o desde un enfoque ecológico sin compromiso con posturas extremas, tales como el panteísmo o la explotación y sojuzgamiento brutal de los recursos naturales.

Confiança e democracia : aspectos de uma instável união estável

Na linguagem comum, confiança denota "segurança íntima de procedimento", "fé" e "esperança", de acordo com o Novo Dicionário Aurélio Buarque de Holanda. Na Ciência Política, a confiança aparece como facilitadora dos regimes democráticos, em uma literatura que, apesar das críticas, atravessa diversos momentos históricos, sendo aplicada, "democraticamente", em diversos países, há quase cinquenta anos. O artigo revisa essa literatura, por vezes incompreendida, para melhor entender aspectos da instável relação entre confiança e democracia: uma união estável muito próxima das bodas de ouro nessa bibliografia. Releva ainda a importância da mesma em democracias como o Brasil, que este ano comemora bodas de prata - 25 anos de regime democrático sem interrupção -, em um cenário de grandes assimetrias sociais e desafios inerentes ao processo de consolidação.

Stability of the factorial structure of metabolic syndrome from childhood to adolescence : a 6-year follow-up study

Background: Metabolic syndrome (MS) is a clustering of cardiometabolic risk factors that is considered a predictor of cardiovascular disease, type 2 diabetes and mortality. There is no consistent evidence on whether the MS construct works in the same way in different populations and at different stages in life. Methods: We used confirmatory factor analysis to examine if a single-factor-model including waist circumference, triglycerides/HDL-c, insulin and mean arterial pressure underlies metabolic syndrome from the childhood to adolescence in a 6-years follow-up study in 174 Swedish and 460 Estonian children aged 9 years at baseline. Indeed, we analyze the tracking of a previously validated MS index over this 6-years period. Results: The estimates of goodness-of-fit for the single-factor-model underlying MS were acceptable both in children and adolescents. The construct stability of a new model including the differences from baseline to the end of the follow-up in the components of the proposed model displayed good fit indexes for the change, supporting the hypothesis of a single factor underlying MS component trends. Conclusions: A single-factor-model underlying MS is stable across the puberty in both Estonian and Swedish young people. The MS index tracks acceptably from childhood to adolescence.

Relationship between water quality, watermilfoil frequency, and weevil distribution in the State of Washington

During the summer of 1997, we surveyed 50 waterbodies in Washington State to determine the distribution of the aquatic weevil Euhrychiopsis lecontei Dietz. We collected data on water quality and the frequency of occurrence of watermilfoil species within selected watermilfoil beds to compare the waterbodies and determine if they were related to the distribution E. lecontei . We found E. lecontei in 14 waterbodies, most of which were in eastern Washington. Only one lake with weevils was located in western Washington. Weevils were associated with both Eurasian ( Myriophyllum spicatum L.) and northern watermilfoil ( M. sibiricum K.). Waterbodies with E. lecontei had significantly higher ( P < 0.05) pH (8.7 ± 0.2) (mean ± 2SE), specific conductance (0.3 ± 0.08 mS cm -1 ) and total alkalinity (132.4 ± 30.8 mg CaCO 3 L -1 ). We also found that weevil presence was related to surface water temperature and waterbody location ( = 24.3, P ≤ 0.001) and of all the models tested, this model provided the best fit (Hosmer- Lemeshow goodness-of-fit = 4.0, P = 0.9). Our results suggest that in Washington State E. lecontei occurs primarily in eastern Washington in waterbodies with pH ≥ 8.2 and specific conductance ≥ 0.2 mS cm -1 . Furthermore, weevil distribution appears to be correlated with waterbody location (eastern versus western Washington) and surface water temperature.

Factors to consider when using native biological control organisms to manage exotic plants

Biological control of exotic plant populations with native organisms appears to be increasing, even though its success to date has been limited. Although many researchers and managers feel that native organisms are easier to use and present less risk to the environment this may not be true. Developing a successful management program with a native insect is dependent on a number of critical factors that need to be considered. Information is needed on the feeding preference of the agent, agent effectiveness, environmental regulation of the agent, unique requirements of the agent, population maintenance of the agent, and time to desired impact. By understanding these factors, researchers and managers can develop a detailed protocol for using the native biological control agent for a specific target plant. . We found E. lecontei in 14 waterbodies, most of which were in eastern Washington. Only one lake with weevils was located in western Washington. Weevils were associated with both Eurasian ( Myriophyllum spicatum L.) and northern watermilfoil ( M. sibiricum K.). Waterbodies with E. lecontei had significantly higher ( P < 0.05) pH (8.7 ± 0.2) (mean ± 2SE), specific conductance (0.3 ± 0.08 mS cm -1 ) and total alkalinity (132.4 ± 30.8 mg CaCO 3 L -1 ). We also found that weevil presence was related to surface water temperature and waterbody location ( = 24.3, P ≤ 0.001) and of all the models tested, this model provided the best fit (Hosmer- Lemeshow goodness-of-fit = 4.0, P = 0.9). Our results suggest that in Washington State E. lecontei occurs primarily in eastern Washington in waterbodies with pH ≥ 8.2 and specific conductance ≥ 0.2 mS cm -1 . Furthermore, weevil distribution appears to be correlated with waterbody location (eastern versus western Washington) and surface water temperature.

Empirical Doppler Characterization of Signals Scattered by Wind Turbines in the UHF Band under Near Field Condition

Time variability of the scattering signals from wind turbines may lead to degradation problems on the communication systems provided in the UHF band, especially under near field condition. In order to analyze the variability due to the rotation of the blades, this paper characterizes empirical Doppler spectra obtained from real samples of signals scattered by wind turbines with rotating blades under near field condition. A new Doppler spectrum model is proposed to fit the spectral characteristics of these signals, providing notable goodness of fit. Finally, the effect of this kind of time variability on the degradation of OFDM signals is studied.

The distribution of Corixidae in relation to the water quality of British lakes: A monitoring model

This article is an attempt to devise a method of using certain species of Corixidae as a basis for the assessment of general water quality in lakes. An empirical graphical representation of the distribution of populations or communities of Corixidae in relation to conductivity, based mainly on English and Welsh lakes, is used as a predictive monitoring model to establish the "expected" normal community at a given conductivity, representing the total ionic concentration of the water body. A test sample from another lake of known conductivity is then compared with "expected" community. The "goodness of fit" is examined visually or by calculation of indices of similarity based on the relative proportions of the constituent species of each community. A computer programme has been devised for this purpose.

I. The crystal structure of trimesic acid. II. Topics in crystallographic calculations

I. Trimesic acid (1, 3, 5-benzenetricarboxylic acid) crystallizes with a monoclinic unit cell of dimensions a = 26.52 A, b = 16.42 A, c = 26.55 A, and β = 91.53° with 48 molecules /unit cell. Extinctions indicated a space group of Cc or C2/c; a satisfactory structure was obtained in the latter with 6 molecules/asymmetric unit - C₅₄O₃₆H₃₆ with a formula weight of 1261 g. Of approximately 12,000 independent reflections within the CuK_α sphere, intensities of 11,563 were recorded visually from equi-inclination Weissenberg photographs.

The structure was solved by packing considerations aided by molecular transforms and two- and three-dimensional Patterson functions. Hydrogen positions were found on difference maps. A total of 978 parameters were refined by least squares; these included hydrogen parameters and anisotropic temperature factors for the C and O atoms. The final R factor was 0.0675; the final "goodness of fit" was 1.49. All calculations were carried out on the Caltech IBM 7040-7094 computer using the CRYRM Crystallographic Computing System.

The six independent molecules fall into two groups of three nearly parallel molecules. All molecules are connected by carboxylto- carboxyl hydrogen bond pairs to form a continuous array of sixmolecule rings with a chicken-wire appearance. These arrays bend to assume two orientations, forming pleated sheets. Arrays in different orientations interpenetrate - three molecules in one orientation passing through the holes of three parallel arrays in the alternate orientation - to produce a completely interlocking network. One third of the carboxyl hydrogen atoms were found to be disordered.

II. Optical transforms as related to x-ray diffraction patterns are discussed with reference to the theory of Fraunhofer diffraction.

The use of a systems approach in crystallographic computing is discussed with special emphasis on the way in which this has been done at the California Institute of Technology.

An efficient manner of calculating Fourier and Patterson maps on a digital computer is presented. Expressions for the calculation of to-scale maps for standard sections and for general-plane sections are developed; space-group-specific expressions in a form suitable for computers are given for all space groups except the hexagonal ones.

Expressions for the calculation of settings for an Eulerian-cradle diffractometer are developed for both the general triclinic case and the orthogonal case.

Photographic materials on pp. 4, 6, 10, and 20 are essential and will not reproduce clearly on Xerox copies. Photographic copies should be ordered.

Feature Selection for Speech Emotion Recognition in Spanish and Basque: On the Use of Machine Learning to Improve Human-Computer Interaction

Study of emotions in human-computer interaction is a growing research area. This paper shows an attempt to select the most significant features for emotion recognition in spoken Basque and Spanish Languages using different methods for feature selection. RekEmozio database was used as the experimental data set. Several Machine Learning paradigms were used for the emotion classification task. Experiments were executed in three phases, using different sets of features as classification variables in each phase. Moreover, feature subset selection was applied at each phase in order to seek for the most relevant feature subset. The three phases approach was selected to check the validity of the proposed approach. Achieved results show that an instance-based learning algorithm using feature subset selection techniques based on evolutionary algorithms is the best Machine Learning paradigm in automatic emotion recognition, with all different feature sets, obtaining a mean of 80,05% emotion recognition rate in Basque and a 74,82% in Spanish. In order to check the goodness of the proposed process, a greedy searching approach (FSS-Forward) has been applied and a comparison between them is provided. Based on achieved results, a set of most relevant non-speaker dependent features is proposed for both languages and new perspectives are suggested.

Chico Xavier e o mundo dos espíritos: um estudo de representações sociais

O médium Chico Xavier (1910-2002) impôs-se no cenário religioso brasileiro como uma das personalidades mais admiradas e polêmicas do país dada a sua postura de afirmar se comunicar com espíritos de pessoas falecidas, atribuindo a elas seus mais de 400 livros psicografados, assim como pelas atividades assistenciais desempenhadas. As comemorações, em 2010, do centenário de seu nascimento teve ampla repercussão, com numerosas matérias na mídia, (re)lançamentos de livros e produção de filmes. Foi nesse contexto que se desenvolveu esta pesquisa sobre as representações sociais produzidas sobre ele por pessoas com ou sem religião, de acordo com a Abordagem Estrutural da Teoria das Representações Sociais. A coleta de dados foi feita através de um questionário padronizado, aplicado via "web", ao qual se associou uma tarefa de evocação livre ao termo indutor "Chico Xavier". Foram analisadas as respostas de 1960 sujeitos, dentre espíritas (56,6%), católicos (15,5%), teístas (12,1%), umbandistas (4,6%), ateus (4,2%), evangélicos (4,1%) e agnósticos (2,8%). A análise das evocações permitiu identificar os seguintes termos, possivelmente centrais, mais compartilhados por esses grupos: amor, caridade e humildade evocado por espíritas, umbandistas, teístas e católicos; espiritismo, mediunidade-psicografia por teístas, católicos, agnósticos e ateus; católicos e teístas distinguiram-se pela referência à bondade e paz; e evangélicos e ateus referiram-se a engano-mentira; agnósticos evocaram ainda o termo caridade; e ateus, os termos charlatão-fraude e doente mental. A construção de árvores de co- ocorrências confirmou os temas "amor" e "espiritismo" como mais característicos de Chico Xavier, sugerindo a existência de duas representações distintas. Nesse sentido, "amor" parece organizar as representações de católicos, espíritas, umbandistas, teístas, e "espiritismo", as de evangélicos, agnósticos e ateus. A análise do questionário revelou o seguinte ranking decrescente dos grupos quanto à sua proximidade com relação a Chico Xavier: espíritas, umbandistas, teístas, católicos, agnósticos, evangélicos e ateus. Em seu conjunto, os dados revelaram afinidades de representação entre os grupos, sendo principalmente semelhantes as representações dos espíritas e umbandistas, e dos teístas e católicos. Observamos uma representação de Chico Xavier construída a partir de três planos de significação: o da "virtude", o do "pertencimento" e o da "verdade". No primeiro, caracteriza-se pela valorização de "amor", que o situa numa ordem de sentido mais abrangente, reconhecendo-o como alguém capaz de ter vivido e demonstrado tal virtude de forma irrecusável, tornando-se dela um exemplo; no segundo, pela valorização de "espiritismo" ocorre sua identificação dentro de limites grupais, como alguém que viveu segundo sua crença e dela se tornou uma figura de destaque. E o terceiro, atravessando esses dois planos, pela atribuição de um sentido de "verdade" ou "mentira" sobre o que ele viveu/ensinou quanto à vida após a morte e a comunicação com espíritos. Desse modo, Chico Xavier, em geral, é representado pelos espíritas, umbandistas, teístas e católicos como alguém virtuoso que viveu/ensinou a verdade; e pelos evangélicos e ateus como um espírita não-virtuoso que viveu/ensinou mentiras. Os agnósticos posicionaram-se, principalmente, de modo ambivalente, mas com pequena tendência a enfatizar a virtude e a verdade em Chico Xavier.

Measurement errors in body size of sea scallops (Placopecten magellanicus) and their effect on stock assessment models

Body-size measurement errors are usually ignored in stock assessments, but may be important when body-size data (e.g., from visual sur veys) are imprecise. We used experiments and models to quantify measurement errors and their effects on assessment models for sea scallops (Placopecten magellanicus). Errors in size data obscured modes from strong year classes and increased frequency and size of the largest and smallest sizes, potentially biasing growth, mortality, and biomass estimates. Modeling techniques for errors in age data proved useful for errors in size data. In terms of a goodness of model fit to the assessment data, it was more important to accommodate variance than bias. Models that accommodated size errors fitted size data substantially better. We recommend experimental quantification of errors along with a modeling approach that accommodates measurement errors because a direct algebraic approach was not robust and because error parameters were diff icult to estimate in our assessment model. The importance of measurement errors depends on many factors and should be evaluated on a case by case basis.