Trends of precipitation extreme indices over a subtropical semi-arid area using PERSIANN-CDR

In this study, satellite-based daily precipitation estimation data from precipitation estimation from remotely sensed information using artificial neural networks (PERSIANN)-climate data record (CDR) are being evaluated in Iran. This dataset (0.25°, daily), which covers over three decades of continuous observation beginning in 1983, is evaluated using rain-gauge data for the period of 1998–2007. In addition to categorical statistics and mean annual amount and number of rainy days, ten standard extreme indices were calculated to observe the behavior of daily extremes. The results show that PERSIANN-CDR exhibits reasonable performance associated with the probability of detection and false-alarm ratio, but it overestimates precipitation in the area. Although PERSIANN-CDR mostly underestimates extreme indices, it shows relatively high correlations (between 0.6316–0.7797) for intensity indices. PERSIANN-CDR data are also used to calculate the trend in annual amounts of precipitation, the number of rainy days, and precipitation extremes over Iran covering the period of 1983–2012. Our analysis shows that, although annual precipitation decreased in the western and eastern regions of Iran, the annual number of rainy days increased in the northern and northwestern areas. Statistically significant negative trends are identified in the 90th percentile daily precipitation, as well as the mean daily precipitation from wet days in the northern part of the study area. The positive trends of the maximum annual number of consecutive dry days in the eastern regions indicate that the dry periods became longer in these arid areas

'Disorder' and Its Evaluative Implications for Psychiatry

The proper definition of the concept of ‘disorder’ could resolve the existing issues in psychiatry today. Christopher Boorse and R.E. Kendell, as proponents of the medical model, aim at defining the concept in scientific and value-free terms. K.W.M. Fulford develops the fact-plus-value model which integrates the factual and evaluative elements. John Z. Sadler applies the Fulfordian account to diagnostic manuals to resolve their inconsistencies. I find Fulford’s initial and later arguments incongruent. His account is also too evaluative given the absence of any restrictions on the place and role of values. Furthermore, it is relatively easy to conclude that given the prominent position of values, facts need not exist as they are essentially evaluative terms with merely an overt factual connotation. Moreover, values provide the benchmark against which facts are assessed (for their degree of value-ladenness) and identified; and this makes facts dependent on and a subclass of values

Micromechanical failure in fiber-reinforced composites

Mikromekaniske brudmekanismer, som forekommer i fiberforstærkede kompositmaterialer, er undersøgt ved hjælp af finite element metoden og eksperimentelt. Analyserne fokuserer på effekten af mikro-skala mekanismer såsom delaminering af fiber/matrix interface, revner i matrix-materialet og mikroporositeter og deres indflydelse på det mikroskopiske og makroskopiske mekaniske respons af kompositmaterialer. Til dette formål er der ved hjælp af kohasiv zone modellering først udført en numerisk analyse for at undersøge mulighederne for at stabilisere revnevækst i interfacet under dominerende Mode-I brud. Som resultat af dette, fremsættes forslag til en metode til at bestemme egenskaber i normalretningen til interfacet. For at evaluere effekten af mikro-skala mekanismerne pa den samlede spændings-/tøjningsrespons i kompositter, etableres to forskellige numeriske metoder: (I) ensartet fiberfordeling og (II) vilkårlig fiberfordeling. I den første fremgangsmåde, er J2 plasticitetsteori implementeret, for at modellere den elasto-plastiske opførsel af matrix-materialet, mens den modificerede Drucker-Prager plasticitetsmodel anvendes i den anden strategi for at modellere den tilnærmelsesvis skøre og trykafhængige opførsel af epoxy. Desuden er skadeslocus for den kompositmaterialet bestemt ved hjælp af numerisk mikromekanik under forskellige belastningsforhold og sammenlignet med Puck’s model. Resultaterne er i meget god overensstemmelse med Puck’s model for forskellige svigtmekanismer. For direkte at validere den numeriske mikrostrukturelle tilgang blev de numeriske resultater sammenlignet med eksperimentelle forsøg. Det blev konstateret, at den mikromekaniske model kan nøjagtigt forudsige revnedannelse som udspringer fra mikroporositeter samt revneudbredelse langs et fiber/matrix interface. Resultaterne af denne afhandling viser, at styrken af kompositmaterialer reduceres betydeligt ved svage interface-egenskaber samt tilstedeværelsen af porositeter. Størrelsen og formen af mikroporositeterne kan også føre til forskellige mikroskopiske revneveje. Afslutningsvist konkluderes det, at den foreliggende numeriske strategi, synes at være en lovende kandidat som redskab til at forudsige det makroskopiske og mikroskopiske mekaniske respons af kompositmaterialer.Micromechanical failure mechanisms occurring in unidirectional fiber-reinforced composites are studied by means of the finite element method as well as experimental testing. This study highlights the effect of micro-scale features such as fiber/matrix interfacial debonding, matrix cracking and microvoids on the microscopic and macroscopic mechanical response of composite materials. To this end, first a numerical study is carried out to explore ways to stabilize interfacial crack growth under dominant Mode-I fracture using the cohesive zone model. Consequently, this study suggests a method to determine the normal interfacial properties. Afterward, two different numerical approaches (I) the regular fiber distribution approach and (II) the random fiber distribution strategy are established to evaluate the effect of the microscale features on the overall stress-strain response of unidirectional composites. In the first approach, the J2 plasticity model is implemented to model the elasto-plastic behavior of the matrix while in the second strategy the modified Drucker-Prager plasticity model is utilized to account for brittle-like and pressure dependent behavior of an epoxy matrix. In addition, the failure locus of the composite lamina under different loading conditions is obtained by means of computational micromechanics and compared with the predictions of Puck’s model. The results are in very good agreement with the predictions of Puck’s model under different interfiber failure modes. In order to validate the numerical microstructral approach accurately, an experimental test was carried out to be compared with the numerical results. It was found that the micromechanical model could accurately predict the crack initiation emanating from microvoids as well as crack propagation along the interfaces. The results of this thesis show that the strength of composite is significantly reduced by weak interfacial properties and the presence of voids. The size and shape of microvoids can also microscopically lead to different crack paths. Finally, the present numerical strategy seems to be a promising tool to predict the macroscopic and microscopic mechanical response of composites

A comparative study on the functional response of Wolbachia-infected and uninfected forms of the parasitoid wasp Trichogramma brassicae

Trichogramma species (Hymenoptera: Trichogrammatidae) are haplo-diploid egg parasitoids that are frequently used as biological control agents against lepidopteran pests. These wasps display two reproductive modes, including arrhenotoky (bisexuality) and thelytoky (unisexuality). Thelytokous forms are often associated with the presence of endosymbiotic Wolbachia bacteria. The use of thelytokous wasps has long been considered as a way to enhance the efficacy of biological control. The present study investigates the potential of a thelytokous Wolbachiainfected and an arrhenotokous uninfected Trichogramma brassicae Bezdenko strain as inundative biocontrol agents by evaluating their functional response towards different egg densities of the factitious host, the Angoumois grain moth, Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae). The results revealed a type II functional response for both strains in which parasitism efficiency decreases with host egg density because of an increasing host handling time. A model with an indicator variable was used to compare the parameters of Holling’s disc equation in different data sets. It was demonstrated that the two strains did not differ in host attack rate. However, the Wolbachia-infected strain did have an increased host handling time when compared to the bisexual strain. Some applied aspects of the findings are discusse

Evaluating the utility of short-term hydrological forecasts in a hydropower system

Le fonctionnement optimal d'un système de réservoirs est un processus décisionnel complexe impliquant, entre autres, l'identication d'un compromis temporel concernant l'utilisation de l'eau : la dernière unité d'eau doit-elle être conservée ou plutôt utilisée pour un usage immédiat? La variabilité des apports hydrologiques complique encore davantage ce processus décisionnel puisque la recherche de ce compromis doit être effectuée sans une connaissance parfaite des conditions futures. De manière générale, l'équilibre optimal entre les utilisations immédiates et futures de l'eau nécessite l'intégration de règles de gestion à court et à long terme. Si les règles à court terme conduisent à des décisions à courte vue, les stratégies opérationnelles à long terme ne sont pas appropriées pour gérer des événements à court terme tels que les inondations. Nous proposons un cadre de modélisation basé sur l'approche de décomposition temporelle (DT) : Les stratégies à moyen/long terme sont tout d'abord déterminées puis utilisées comme limites pour l'optimisation des stratégies à court terme. Le modèle d'optimisation à moyen terme capture la persistance temporelle trouvée dans le processus des apports hydrologiques hebdomadaires, alors que les prévisions hydrologiques d'ensemble (PHE) sont utilisées pour piloter le modèle à court terme sur un pas de temps journalier. Plus spécifiquement, la programmation dynamique stochastique duale (SDDP) génère les fonctions des bénéces de valeur hebdomadaires qui sont ensuite imposées à un modèle de programmation linéaire implémenté sur chaque membre des PHE de 14 jours. Ce cadre de modélisation est mis en oeuvre selon un mode de gestion en horizon roulant sur une cascade de centrales hydroélectriques dans le bassin de la rivière Gatineau dans la province du Québec au Canada. À l'aide de ce cadre de modélisation, nous analysons la relation entre la valeur économique et les caractéristiques statistiques des PHE. Les résultats montrent que l'énergie générée par le système hydroélectrique augmente avec la précision et la résolution de la prévision, mais que la relation n'est pas univoque. En effet, d'autres facteurs semblent contribuer à l'utilité de la prévisionThe optimal operation of a system of reservoirs is a complex decision-making problem involving, among others, the identification of a temporal trade-offs regarding the use of water. Should the last unit of water be kept in storage or rather be released for use downstream? The variability of natural inflows further complicates this decision-making problem: at any given point in space and time, this trade-off must be made without a perfect knowledge of future reservoir in flows. Generally speaking, the optimal balance between immediate and future uses of water requires the integration of short- and long-term policies. If short-term policies lead to shortsighted decisions, long-term operational strategies are not appropriate to handle short-term events such as floods. We propose a modeling framework based on the time decomposition (TD) approach: mid/long-term policies are determined first and then used as boundary conditions for the optimization of short-term policies. The mid-term optimization model captures the temporal persistence found in the weekly streamflow process whereas Ensemble Streamflow Forecasts (ESF) are used to drive the short-term model on a daily time step. More specifically, a Stochastic Dual Dynamic Programming (SDDP) generates the weekly benefit-to-go functions that are then imposed to a linear programming model implemented on each 14-days member of the ESF. This modelling framework is implemented in a rolling-horizon mode on a cascade of hydropower stations in the Gatineau River basin, Quebec, Canada. Using this modelling framework, we analyze the relationship between the economic value of different sets of short-term hydrologic forecasts. The results show that the energy generated by the hydropower system increases with the forecast's accuracy and resolution but that the relationship is not univocal; other factors seem to contribute to the forecast's utility

Let Me Tell You What It Means: Reading Beyond Humor in Selected Iranian-American Memoirs, Stand-up Comedy, and Film in the Post-9/11 Era

ABSTRACT Since the tragic events of September 11, 2001, Muslims in America have continued to remain the subject of cultural and political debates. In their artistic endeavours, Muslim artists have tried to rectify the negative and mediated images attributed to Islam, Muslims, and their cultures. In this dissertation, I look at Iranian works from the diaspora that not only represent Iranian culture and attempt to raise public awareness in America, but also extensively wade into humor as their linking theme. It is humor embedded in socio-cultural and political implications along with cultural representations that constitute my analysis in this dissertation. I have benefitted from a wide range of textual materials and visual sources—electronic libraries, media coverages, and Internet talks and interviews—to investigate the rhetoric of Firoozeh Dumas’s selected memoirs entitled Funny in Farsi (2003) and Laughing without an Accent (2005), the stand-up comedian Maz Jobranis’ Axis of Evil (2005-2007), and Ramin Niami’s romantic comedy film entitled Shirin in Love (2014). Critical voices of the Iranian diaspora scholars along with Mikhail Bakhtin’s notions of the carnivalesque, heteroglossia and dialogism, and Linda Hutcheon’s concepts of irony and parody inform the theoretical framework of my study. I suggest that the artworks function as a site where social, cultural, political, and linguistic practices are re-negotiated, re-defined, and re-presented to the reading public and/or audiences. Keywords: Humor, the rhetoric, the Iranian diaspora, the carnivalesque, heteroglossia, dialogism, irony, parody, cultural representation

A Survey on Compiler Autotuning using Machine Learning

Since the mid-1990s, researchers have been trying to use machine-learning based approaches to solve a number of different compiler optimization problems. These techniques primarily enhance the quality of the obtained results and, more importantly, make it feasible to tackle two main compiler optimization problems: optimization selection (choosing which optimizations to apply) and phase-ordering (choosing the order of applying optimizations). The compiler optimization space continues to grow due to the advancement of applications, increasing number of compiler optimizations, and new target architectures. Generic optimization passes in compilers cannot fully leverage newly introduced optimizations and, therefore, cannot keep up with the pace of increasing options. This survey summarizes and classifies the recent advances in using machine learning for the compiler optimization field, particularly on the two major problems of (1) selecting the best optimizations and (2) the phase-ordering of optimizations. The survey highlights the approaches taken so far, the obtained results, the fine-grain classification among different approaches and finally, the influential papers of the field.Comment: version 5.0 (updated on September 2018)- Preprint Version For our Accepted Journal @ ACM CSUR 2018 (42 pages) - This survey will be updated quarterly here (Send me your new published papers to be added in the subsequent version) History: Received November 2016; Revised August 2017; Revised February 2018; Accepted March 2018