109 research outputs found
A Multi-modal Approach to Fine-grained Opinion Mining on Video Reviews
Despite the recent advances in opinion mining for written reviews, few works
have tackled the problem on other sources of reviews. In light of this issue,
we propose a multi-modal approach for mining fine-grained opinions from video
reviews that is able to determine the aspects of the item under review that are
being discussed and the sentiment orientation towards them. Our approach works
at the sentence level without the need for time annotations and uses features
derived from the audio, video and language transcriptions of its contents. We
evaluate our approach on two datasets and show that leveraging the video and
audio modalities consistently provides increased performance over text-only
baselines, providing evidence these extra modalities are key in better
understanding video reviews.Comment: Second Grand Challenge and Workshop on Multimodal Language ACL 202
Reconsiderando la metodologÃÂa FAO sobre el cálculo del número de personas que pasan hambre en el mundo
FAO measure of undernourishment is calculated based on three main parameters: dietary energy supply (DES), minimum dietary energy requirement (MDER), and the coefficient of variation of dietary energy consumption (CV). In the current implementation of this methodology, the DES and the MDER change over time, as would be expected. The CV, however, remains constant. However, we expect the CV to change over time and be a function of income and prices. This paper discusses why the CV should change in response to changes in these variables, and suggests a practical way to estimate changes in the CV over time in the absence of survey data.Income, prices, consumption, undernourishment, Food Consumption/Nutrition/Food Safety, Food Security and Poverty, E21, O11, O19,
Video Analysis for Understanding Human Actions and Interactions
Each time that we act, our actions are not just conditioned by the spatial information, e.g., objects, people, and the scene where we are involved. These actions are also conditioned temporally with the previous actions that we have done. Indeed, we live in an evolving and dynamic world. To understand what a person is doing, we reason jointly over spatial and temporal information. Intelligent systems that interact with people and perform useful tasks will also require this ability. In light of this need, video analysis has become, in recent years, an essential field in computer vision, providing to the community a wide range of tasks to solve.
In this thesis, we make several contributions to the literature of video analysis, exploring different tasks that aim to understand human actions and interactions. We begin by considering the challenging problem of human action anticipation. In this task, we seek to predict a person's action as early as possible before it is completed. This task is critical for applications where machines have to react to human actions. We introduce a novel approach that forecasts the most plausible future human motion by hallucinating motion representations.
Then, we address the challenging problem of temporal moment localization. It consists of finding the temporal localization of a natural-language query in a long untrimmed video. Although the queries could be anything that is happening within the video, the vast majority of them describe human actions. In contrast with the propose and rank approaches, where methods create or use predefined clips as candidates, we introduce a proposal-free approach that localizes the query by looking at the whole video at once. We also consider the temporal annotations' subjectivity and propose a soft-labelling using a categorical distribution centred on the annotated start and end.
Equipped with a proposal-free architecture, we tackle the temporal moment localization introducing a spatial-temporal graph. We found that one of the limitations of the existing methods is the lack of spatial cues involved in the video and the query, i.e., objects and people. We create six semantically meaningful nodes. Three that are feed with visual features of people, objects, and activities, and the other three that capture the relationship at the language level of the "subject-object,'' "subject-verb," and "verb-object." We use a language-conditional message-passing algorithm to capture the relationship between nodes and create an improved representation of the activity. A temporal graph uses this new representation to determine the start and end of the query.
Last, we study the problem of fine-grained opinion mining in video review using a multi-modal setting. There is increasing use of video as a source of information for guidance in the shopping process. People use video reviews as a guide to answering what, why, and where to buy something. We tackle this problem using the three different modalities inherently present in a video ---audio, frames, and transcripts--- to determine the most relevant aspect of the product under review and the sentiment polarity of the reviewer upon that aspect. We propose an early fusion mechanism of the three modalities. In this approach, we fuse the three different modalities at the sentence level. It is a general framework that does not lay in any strict constraints on the individual encodings of the audio, video frames and transcripts
Structural Features of Antitumor Titanium Agents and Related Compounds
Previous studies established some Ti compounds as having marked activity against tumors of the
gastrointestinal tract and lack of side effects common to widely used cytostatic agents. We describe pertinent
structural features of known antitumor Ti agents and other potentially active compounds. Particularly
noteworthy features are that Ti-O bonds are short and Ti-O-Ti bond angles are large, demonstrating that in
these compounds the O binding has high s-character approaching sp hybridization
Diseño sÃsmico por desempeño de taludes proyectados en base a criterios de estabilidad estática
Tesis (Ingeniero Civil)Tradicionalmente, y desde el punto de vista de la práctica de ingenierÃa, el diseño de taludes bajo la acción de cargas estáticas y/o sÃsmicas ha sido abordado por medio de criterios de estabilidad. Matemáticamente, lo anterior se expresa en términos de un factor de seguridad (FS), que corresponde al cuociente entre las fuerzas solicitantes y resistentes involucradas en el problema.
Para este tipo de análisis, es común utilizar los denominados métodos de equilibrio lÃmite. Éstos consideran el balance de fuerzas y/o momentos en una masa de suelo, que se supone rÃgida–perfectamente plástica, sobre un conjunto de potenciales superficies de falla. De esta forma, se debe garantizar que para todas ellas, el FS sea superior al mÃnimo definido en las bases de diseño de proyecto.
En particular, la estabilidad sÃsmica de taludes se suele analizar por medio de métodos pseudoestáticos, en los cuales los efectos de un terremoto dado sobre la estructura son modelados a través de fuerzas horizontales y/o verticales que actúan en el centro de gravedad de la masa de suelo potencialmente inestable. Estas fuerzas se expresan como una fracción del peso de la cuña de suelo analizada por medio de coeficientes sÃsmicos, y deben poder representar razonablemente las caracterÃsticas principales del terremoto de diseño; por lo que en la práctica resulta complejo estimarlas de forma apropiada.
Por este motivo, en lugar de diseñar sobre la base de fuerzas, suele ser preferible diseñar sobre la base de ciertos desplazamientos admisibles que no comprometan la estabilidad global del talud y permitan mantenerlo operativo luego de concluido el sismo. Esta forma de abordar el problema es lo que da origen a los llamados métodos de diseño por desempeño.
En este trabajo se propone una metodologÃa simple para abordar el diseño sÃsmico por desempeño de taludes homogéneos que han sido proyectados bajo criterios de estabilidad estática. Se busca establecer relaciones entre el FS asociado a un determinado diseño estático y el correspondiente coeficiente sÃsmico crÃtico ky del talud. De esta manera, utilizando procedimientos basados en el denominado método del bloque deslizante de Newmark, como por ejemplo el propuesto por Richards y Elms (1979), el proyectista tiene la opción de anticipar el nivel de desempeño de un talud dado, o bien conocer los requerimientos de estabilidad que debe satisfacer un talud para un nivel de desempeño objetivo que se busque satisfacer bajo un sismo de diseño.
A partir de un conjunto de análisis numéricos realizados utilizando el software SLOPE/W (GEO-SLOPE International Ltd.), se presentan soluciones en forma de ábacos de diseño para distintos tipos de suelo, geometrÃas del talud, y niveles de sobrecarga distribuida uniformemente a nivel de coronamiento.Typically, and in the context of engineering practice, the design of slopes under the action of both static and seismic loading has been addressed through stability criteria. Mathematically, this is expressed in terms of a factor of safety (FS), which is the ratio between the driving and resisting forces involved into the problem.
For this type of analyses, it is common to use the so-called limit equilibrium methods. They consider the balance of forces and/or moments in a soil mass, which is assumed to behave in a rigid-perfectly plastic way, over a series of potential failure surfaces. In this way, it has to be guaranteed that for all of them, the FS is greater than the minimum value defined in the design criteria of a certain project.
In particular, the seismic stability of slopes is usually analized by pseudo-static methods, in which the effects of a given earthquake over the structure are modeled through horizontal and/or vertical forces, which act in the center of gravity of the potentially unstable soil mass. These forces are expressed as a fraction of the weight of the soil wedge analyzed, and they have to properly represent the main design-earthquake characteristics; so in practice, it is complex to estimate them accurately.
For this reason, instead of designing through a force-based approach, it is preferable to do it over the basis of allowable displacements, which do not compromise the overall system stability and allow keeping it operative after the design-earthquake occurrence. This way to approach the seismic design of slopes is known as performance-based design.
In this work, a simple methodology is proposed to address the performance-based seismic design of homogeneous slopes that have been designed using static-stability design criteria. It looks for stablish relationships between the FS associated to a certain static slope design and the corresponding critical pseudo-static seismic coefficient ky. In this way, by using procedures based on the well-known Newmark’s sliding block method, as proposed for example by Richards and Elms (1979), the engineer has the option to anticipate the level of performance for a given slope. In addition, it is possible to know the stability requirements that a certain slope has to satisfy for some pre-defined target performance level in a design-earthquake scenario.
From a series of analyses performed using the software SLOPE/W (GEO-SLOPE International Ltd.), solutions in the form of design charts are presented for different types of soil, slope geometries, and surcharge loads uniformly distributed over the top surface of the slope
Luis Cousino Mac Iver : vida, obra e Influencia en el derecho penal Actual
96 p.Don LuÃs Cousino Mac Iver es reconocido y recordado como uno de los juristas chilenos mas importantes del siglo XX. De ello nace el interés de realizar un estudio sobre su vida y obra, asà como de la influencia que ejerce en la doctrina penal actual. En la realización de este estudio se recopilan datos y antecedentes tanto biográficos como bibliográficos del autor en comento, con el fin de hacer un análisis de este y determinar la importancia de su obra. La influencia de LuÃs Cousino Mac Iver en el derecho penal actual se devela, a través de importantes textos penales de reciente data. La metodologÃa a aplicar será la correspondiente a una investigación de carácter dogmático. En definitiva, queremos se resalte la importancia LuÃs Cousino Mac Iver en la historia y estudio del derecho penal chileno
Reconsiderando la metodologÃa FAO sobre el cálculo del número de personas que pasan hambre en el mundo
[EN] FAO measure of undernourishment is calculated based on three main parameters: dietary energy supply (DES), minimum dietary energy requirement (MDER), and the coefficient of variation of dietary energy consumption (CV). In the current implementation of this methodology, the DES and the MDER change over time, as would be expected. The CV, however, remains constant. However, we expect the CV to change over time and be a function of income and prices. This paper discusses why the CV should change in response to changes in these variables, and suggests a practical way to estimate changes in the CV over time in the absence of survey data.[ES] La FAO estima el número de personas que pasan hambre sobre la base de tres parámetros principales: el suministro de energÃa alimentaria (SEA), el requisito mÃnimo de energÃa alimentaria (MDER), y el coeficiente de variación del consumo de energÃa alimentaria (CV). Mientras que los dos primeros evolucionan con el tiempo y siguen una trayectoria coherente con la teorÃa económica, el CV se mantiene constante en la estimación. El objetivo de este trabajo es justificar el carácter dinámico del CV y presentar un método práctico para estimar su evolución temporal, cuando no se dispone de datos provenientes de encuestas nacionales.Morales-Opazo, C.; Barreiro-Hurlé, J. (2011). Reconsidering the FAO methodology for the calculation of the number of hungry people in the world. EconomÃa Agraria y Recursos Naturales - Agricultural and Resource Economics. 11(2):63-82. https://doi.org/10.7201/earn.2011.02.03SWORD638211
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