Affect-based information retrieval

One of the main challenges Information Retrieval (IR) systems face nowadays originates from the semantic gap problem: the semantic difference between a user’s query representation and the internal representation of an information item in a collection. The gap is further widened when the user is driven by an ill-defined information need, often the result of an anomaly in his/her current state of knowledge. The formulated search queries, which are submitted to the retrieval systems to locate relevant items, produce poor results that do not address the users’ information needs. To deal with information need uncertainty IR systems have employed in the past a range of feedback techniques, which vary from explicit to implicit. The first category of feedback techniques necessitates the communication of explicit relevance judgments, in return for better query reformulations and recommendations of relevant results. However, the latter happens at the expense of users’ cognitive resources and, furthermore, introduces an additional layer of complexity to the search process. On the other hand, implicit feedback techniques make inferences on what is relevant based on observations of user search behaviour. By doing so, they disengage users from the cognitive burden of document rating and relevance assessments. However, both categories of RF techniques determine topical relevance with respect to the cognitive and situational levels of interaction, failing to acknowledge the importance of emotions in cognition and decision making. In this thesis I investigate the role of emotions in the information seeking process and develop affective feedback techniques for interactive IR. This novel feedback framework aims to aid the search process and facilitate a more natural and meaningful interaction. I develop affective models that determine topical relevance based on information gathered from various sensory channels, and enhance their performance using personalisation techniques. Furthermore, I present an operational video retrieval system that employs affective feedback to enrich user profiles and offers meaningful recommendations of unseen videos. The use of affective feedback as a surrogate for the information need is formalised as the Affective Model of Browsing. This is a cognitive model that motivates the use of evidence extracted from the psycho-somatic mobilisation that occurs during cognitive appraisal. Finally, I address some of the ethical and privacy issues that arise from the social-emotional interaction between users and computer systems. This study involves questionnaire data gathered over three user studies, from 74 participants of different educational background, ethnicity and search experience. The results show that affective feedback is a promising area of research and it can improve many aspects of the information seeking process, such as indexing, ranking and recommendation. Eventually, it may be that relevance inferences obtained from affective models will provide a more robust and personalised form of feedback, which will allow us to deal more effectively with issues such as the semantic gap

Analyse biomécanique multidimensionnelle du geste de tourner le volant chez les conducteurs sans déficiences motrices

Tourner le volant d une automobile peut s avérer difficile pour les conducteurs ayant des déficiences motrices des membres supérieurs. En effet, ce mouvement demande une grande mobilité et une force musculaire non négligeable. A ce jour, les directions assistées automobiles sont réglées uniquement sur le ressenti des conducteurs sans déficiences motrices. Le projet ANR VTT VolHand, dans lequel ce travail de recherche s inscrit, ambitionne d apporter une réponse à cette problématique. L objectif de cette thèse est de renseigner la biomécanique du geste déjà chez le conducteur sans déficiences motrices (sain). Pour cela, l interaction main/volant, ainsi que la cinématique (ex. angles articulaires) et la dynamique (ex. efforts sur volant, efforts articulaires) du geste de tourner le volant sont étudiés au travers de plusieurs analyses multidimensionnelles multivariables (atemporelle et temporelle). La méthode originale proposée s appuie sur un découpage flou du volant et des variables cinématiques et dynamiques. La population expérimentée compte une centaine de sujets, dont 23 sujets sans déficience motrice. La plateforme expérimentale regroupe principalement un simulateur automobile compact permettant le recueil des efforts développés par chaque main, une consigne de suivi de trajectoire incitant le conducteur à reproduire un angle désiré et un système optoélectronique mesurant le geste de tourner le volant.Les résultats de l analyse de l interaction main/volant mettent en évidence 3 profils de conducteurs : les conducteurs croiseurs, les conducteurs croiseurs asymétriques et les conducteurs non croiseurs. L analyse des variables cinématiques et dynamiques montrent que les variables dynamiques résultant du tirer/pousser le volant sont discriminantes. Deux nouveaux profils sont alors identifiés : les pousseurs moyens et les tireurs. En majorité, les conducteurs sains tendent à croiser les mains et à pousser sur le volant lors de la réalisation d un geste de tourner le volant à basse vitesse.Plusieurs perspectives sont proposées à court terme, à moyen terme et à long terme. L une d entre elles concerne l adaptation de l assistance aux caractéristiques motrices des conducteurs avec déficience motrice.Steering wheel can be difficult for divers with disabilities on upper limb. Indeed, the steering action might require a large range of motion of upper limb and some muscular strength. Power steering systems that are currently proposed in car were implemented to match non disabled driver feelings and needs. ANR VTT VolHand project wants to enlarge the field of power steering system to drivers with disabilities on upper limbs. The present work is a part of this project. As a preliminary approach, the objective was to analyze the upper limb motion of healthy drivers during a steering exercise. Different multivariable analyses (low level of time summarizing and high level of time summarizing) were done to study hand/wheel interactions, kinematics variables (e.g. joint angles) and dynamics variables (e.g. joint torques). An original fuzzy windowing was proposed to describe hand position on steering wheel, kinematic and dynamics variables. One hundred subjects participated to experiment, included 23 healthy subjects, which consisted on a low speed steering task. The experimental platform was composed of a compact driving simulator, that allow the measurement of each hand effort on the steering wheel, a steering exercise based on a line following protocol, and a motion capture system.Analysis of hand/wheel interaction showed the existence of three driver profiles: hand crossing, asymmetric hand crossing and non hand crossing. Analysis of kinematics and dynamics variables showed that pulling/pushing forces were also discriminating. As a consequence, two additional profiles were identified: mean pushing drivers and pulling drivers. Overall, healthy drivers were hand crossing and mean pushing drivers during a low speed steering task.Short, middle and long prospects are proposed. One of them concerns automotive power steering system adaptation for disabled drivers.VALENCIENNES-Bib. électronique (596069901) / SudocSudocFranceF

Gesture Interaction at a Distance

The aim of this work is to explore, from a perspective of human behavior, which\ud gestures are suited to control large display surfaces from a short distance away; why that is so; and, equally important, how such an interface can be made a reality. A well-known example of the type of interface that is the focus in this thesis is portrayed in the science fiction movie ‘Minority Report’. The lead character of this movie uses hand gestures such as pointing, picking-up and throwing-away to interact with a wall-sized display in a believable way. Believable, because the gestures are familiar from everyday life and because the interface responds predictably. Although only fictional in this movie, such gesture-based interfaces can, when realized, be applied in any environment that is equipped with large display surfaces. For example, in a laboratory for analyzing and interpreting large data sets; in interactive shopping windows to casually browse a product list; and in the operating room to easily access a patient’s MRI scans. The common denominator is that the user cannot or may not touch the display: the interaction occurs at arms-length and larger distances