Verification of emotion recognition from facial expression

Analysis of facial expressions is an active topic of research with many potential applications, since the human face plays a significant role in conveying a person’s mental state. Due to the practical values it brings, scientists and researchers from different fields such as psychology, finance, marketing, and engineering have developed significant interest in this area. Hence, there are more of a need than ever for the intelligent tool to be employed in the emotional Human-Computer Interface (HCI) by analyzing facial expressions as a better alternative to the traditional devices such as the keyboard and mouse. The face is a window of human mind. The examination of mental states explores the human’s internal cognitive states. A facial emotion recognition system has a potential to read people’s minds and interpret the emotional thoughts to the world. High rates of recognition accuracy of facial emotions by intelligent machines have been achieved in existing efforts based on the benchmarked databases containing posed facial emotions. However, they are not qualified to interpret the human’s true feelings even if they are recognized. The difference between posed facial emotions and spontaneous ones has been identified and studied in the literature. One of the most interesting challenges in the field of HCI is to make computers more human-like for more intelligent user interfaces. In this dissertation, a Regional Hidden Markov Model (RHMM) based facial emotion recognition system is proposed. In this system, the facial features are extracted from three face regions: the eyebrows, eyes and mouth. These regions convey relevant information regarding facial emotions. As a marked departure from prior work, RHMMs for the states of these three distinct face regions instead of the entire face for each facial emotion type are trained. In the recognition step, regional features are extracted from test video sequences. These features are processed according to the corresponding RHMMs to learn the probabilities for the states of the three face regions. The combination of states is utilized to identify the estimated emotion type of a given frame in a video sequence. An experimental framework is established to validate the results of such a system. RHMM as a new classifier emphasizes the states of three facial regions, rather than the entire face. The dissertation proposes the method of forming observation sequences that represent the changes of states of facial regions for training RHMMs and recognition. The proposed method is applicable to the various forms of video clips, including real-time videos. The proposed system shows the human-like capability to infer people’s mental states from moderate level of facial spontaneous emotions conveyed in the daily life in contrast to posed facial emotions. Moreover, the extended research work associated with the proposed facial emotion recognition system is forwarded into the domain of finance and biomedical engineering, respectively. CEO’s fear facial emotion has been found as the strong and positive predictor to forecast the firm stock price in the market. In addition, the experiment results also have demonstrated the similarity of the spontaneous facial reactions to stimuli and inner affective states translated by brain activity. The results revealed the effectiveness of facial features combined with the features extracted from the signals of brain activity for multiple signals correlation analysis and affective state classification

Limits to temporal synchronization in fundamental hand and finger actions

Coordinated movement is critical not only to sports technique and performance but to daily living and as such represents a fundamental area of research. Coordination requires being able to produce the right actions at the right time and has to incorporate perception, cognition, and forceful neuro-muscular interaction with the environment. Coordinated movements of the hands and fingers are some of the most complex activities undertaken where continuous learning and adaptation take place, but the temporal variability of the most basic movement components is still unknown. This thesis investigates the extent of temporal variability in the execution of four different simple hand and finger coordination tasks, with the purpose to find the various intrinsic temporal variability which limit the ability to coordinate the hands in space and time. Study one showed that in a synchronized bi-lateral two finger tapping test (<<1 cm movement to target) the best participant had a temporaltiming variability of 4.8 ms whereas the largest time variability could be as high as 24.8 ms. No obvious improvement was found after transfer practice, whereas the average time variability for asynchronized tapping decreased from 62.1 ms to 30.3 ms after instructed practice indicating a likely change in task grouping. Study two showed that in a unilateral thumb-index finger pinch and release test, the largest mean timing variability was 12 ms for pinching irrespective of performing the task in a slow alert manner or at a faster speed. However, the mean temporal variability for release was only 6.3 ms when the task was performed in a more alert manner and indicates that release is more accurately controlled temporally than grip. Study three suggested that in a unilateral sagittal plane throwing action of the lower arm and hand, that elbow and wrist coordination for dynamic index finger tip location was better with a radial-ulnar deviation, darts-type, throwing action than a wrist flexor-extensor type action, basketball free throw type action (the mean variability was 37.5 ms and 27.2 ms, respectively). Study four compared the variability in bi-lateral finger tapping between voluntary tapping and involuntary finger contraction tapping. Electrically stimulated neural contractions had significantly lower force onset variability than voluntary or direct magnetic stimulation of muscles (6 ms, 9.5 ms, and 10.3 ms for electrically stimulated, voluntary and Transcranial Magnetic Stimulation stimulated contraction). This work provides a comprehensive analysis of the temporal variability in various fundamental digital movement tasks that can aid with the understanding of basic human coordination in sporting, daily living and clinical areas

The rr-coloring and maximum stable set problem in hypergraphs with bounded matching number and edge size

Motivated by the analogous questions in graphs, we study the complexity of coloring and stable set problems in hypergraphs with forbidden substructures and bounded edge size. Letting $\nu(G)$ denote the maximum size of a matching in $H$, we obtain complete dichotomies for the complexity of the following problems parametrized by fixed $r, k, s \in \mathbb{N}$: $r$-Coloring in hypergraphs $G$ with edge size at most $k$ and $\nu(G) \leq s$; $r$-Precoloring Extension in $k$-uniform hypergraphs $G$ with $\nu(G) \leq s$; $r$-Precoloring Extension in hypergraphs $G$ with edge size at most $k$ and $\nu(G) \leq s$; Maximum Stable Set in $k$-uniform hypergraphs $G$ with $\nu(G) \leq s$; Maximum Weight Stable Set in $k$-uniform hypergraphs with $\nu(G) \leq s$; as well as partial results for $r$-Coloring in $k$-uniform hypergraphs $\nu(G) \leq s$. We then turn our attention to $2$-Coloring in 3-uniform hypergraphs with forbidden induced subhypergraphs, and give a polynomial-time algorithm when restricting the input to hypergraphs excluding a fixed one-edge hypergraph. Finally, we consider linear 3-uniform hypergraphs (in which every two edges share at most one vertex), and show that excluding an induced matching in $G$ implies that $\nu(G)$ is bounded by a constant; and that $3$-coloring linear $3$-uniform hypergraphs $G$ with $\nu(G) \leq 532$ is NP-hard

ERROR ANALYSIS OF A THROWING ACTION

The purpose of the present study was to characterise the temporal regulation of a simple but natural movement, forearm throwing. Our finding is the time leg of wrist flexion throwing is less consistent than that ofdeviation throwing. Two experiments demonstrate two potential error factors involved in a simple throwing action. The result data demonstrated that there is a limit with which people can perform self-timing activities. The limit for best people could do in releasing two fingers is 6ms, 12ms for deviations throwing only, flexion throwing with finger releasing is about 18 ms, but was about 25ms in deviation throwing with finger releasing

Multi-dimensional measures of geography and the opioid epidemic: place, time and context

The opioid crisis has hit the United States hard in recent years. Behavioral patterns and social environments associated with opioid use and misuse vary significantly across communities. It is important to understand the geospatial prevalence of opioid overdoses and other impacts related to the crisis in order to provide a targeted response at different locations. This dissertation contributes a framework for understanding spatial and temporal patterns of drug prevalence, treatment services access and associated socio-environmental factors for opioid use and misuse. This dissertation addresses three main questions related to geography and the opioid epidemic: 1) How did drug poisoning deaths involving heroin evolve over space and time in the U.S. between 2000-2016; 2) How did access to opioid use disorder treatment facilities and emergency medical services vary spatially in New Hampshire during 2015-2016; and 3) What were the relations between socio-environmental factors and numbers of emergency department patients with drug-related health problems over space and time in Maryland during 2016-2018. For the first study, this dissertation developed a spatial and temporal data model to investigate trends of heroin mortality over a 17-year period (2000-2016). The research presented in this dissertation also involved developing a composite index to analyze spatial accessibility to both opioid use disorder treatment facilities and emergency medical services and compared these locations with the locations of deaths involving fentanyl to identify possible gaps in services. In the third study for this dissertation, I utilized socially-sensed data to identify neighborhood characteristics and investigated spatial and temporal relationships with emergency department patients with drug-related health problems admitted to the four hospitals in the western Baltimore area in Maryland during 2016 to 2018, in order to identify the dynamic patterns of the associations in terms of various socio-environmental factors

Coloring Algorithms for Graphs and Hypergraphs with Forbidden Substructures

This thesis mainly focus on complexity results of the generalized version of the $r$-Coloring Problem, the $r$-Pre-Coloring Extension Problem and the List $r$-Coloring Problem restricted to hypergraphs and ordered graphs with forbidden substructures. In the context of forbidding non-induced substructure in hypergraphs, we obtain complete complexity dichotomies of the $r$-Coloring Problem and the $r$-Pre-Coloring Extension Problem in hypergraphs with bounded edge size and bounded matching number, as well as the $r$-Pre-Coloring Extension Problem in hypergraphs with uniform edge size and bounded matching number. We also get partial complexity result of the $r$-Coloring Problem in hypergraphs with uniform edge size and bounded matching number. Additionally, we study the Maximum Stable Set Problem and the Maximum Weight Stable Set Problem in hypergraphs. We obtain complexity dichotomies of these problems in hypergraphs with uniform edge size and bounded matching number. We then give a polynomial-time algorithm of the 2-Coloring Problem restricted to the class of 3-uniform hypergraphs excluding a fixed one-edge induced subhypergraph. We also consider linear hypergraphs and show that 3-Coloring in linear 3-uniform hypergraphs with either bounded matching size or bounded induced matching size is NP-hard if the bound is a large enough constant. This thesis also contains a near-dichotomy of complexity results for ordered graphs. We prove that the List-3-Coloring Problem in ordered graphs with a forbidden induced ordered subgraph is polynomial-time solvable if the ordered subgraph contains only one edge, or it is isomorphic to some fixed ordered 3-vertex path plus isolated vertices. On the other hand, it is NP-hard if the ordered subgraph contains at least three edges, or contains a vertex of degree two and does not satisfy the polynomial-time case mentioned before, or contains two non-adjacent edges with a specific ordering. The complexity result when forbidding a few ordered subgraphs with exactly two edges is still unknown

Détermination du pouvoir entartrant de l'eau d'un circuit via l'utilisation d'une microbalance électrochimique à quartz ultrasensible.

The scaling phenomenon could cause serious economic and technical problems to the cooling circuits of nuclear power plants. The objective of this work is to develop an original method, which allows rapid and in situ evaluation of the scaling potential of water. Such method should play a preventive role for optimal monitoring of the scaling risk. Three methods to test water scaling potential were examined and compared in this study: the method of Fast Controlled Precipitation (FCP), the method of electrochemical Quartz Crystal Microbalance (electrochemical QCM) and an original method of the pre-calcified microbalance (E-QCME). Indicative factors obtained by these three methods, which are representative of waterscaling potential, were analyzed and compared. Based on the results of the experiments on synthetic waters of controlled quality, a relationship was established between water scaling potential and chosen indicative factors for each method. These three methods have also been coupled with X-ray Diffraction measurements, Scanning Electron Microscopy and Infrared Spectroscopy, in order to characterize the deposit formed by different methods and with different synthetic waters. The comparison between these three methods shows that the EQCM-E method possesses advantages over the FCP method and the electrochemical QCM method, which can carry out in situ measurements, on a short time scale, with a nice sensitivity, of the water scaling potential. A first group of experiments was also conducted that coupled the SAXS measurements (SmallAngle X ray Scattering) with the FCP method for finer understanding of the mechanism of calcium carbonate formation and precipitation. During these experiments, in situ calcium carbonate nano clusters in metastable water were observed and characterized, before the homogeneous precipitation, which could probably play an important orle in the scaling phenomenon as precursors.Le phénomène d’entartrage a des conséquences économiques et techniques défavorables pour le circuit de refroidissement dans les centrales nucléaires de production d'électricité. L’objectif de ce travail est de développer une méthodologie originale, qui permet d’évaluer de manière in situ et rapide, le pouvoir entartrant d’une eau. Une telle méthodologie jouerait un rôle préventif pour permettre une surveillance optimale du circuit vis-à-vis du risque d’entartrage. Pour ce faire, trois méthodes d’évaluation du pouvoir entartrant des eaux ont été examinées et comparées dans cette étude : la méthode de Précipitation Contrôlée Rapide (PCR), la méthode de microbalance à quartz (QCM) électrochimique et une méthode originale de l’Entartrage sur la microbalance pré-Entartrée (E-QCM-E). Les indicateurs représentatifs du pouvoir entartrant d’une eau donnée, obtenus par ces trois méthodes, ont été analysés et comparés. En étudiant les résultats des expériences sur des eaux synthétiques de qualité contrôlée, des relations entre le pouvoir entartrant des eaux et ces indicateurs ont été établies. Ces trois méthodes ont aussi été couplées avec lesmesures de Diffraction des Rayons X, de Microscopie Electronique à Balayage et de Spectroscopie Infrarouge pour caractériser les dépôts formés par chaque méthode et avec différentes qualités d’eau. La comparaison entre ces trois méthodes a montré que la méthode d’E-QCM-E présente des avantages par rapport aux méthodes de PCR et QCM électrochimique, qui permet des mesures in situ, sur une échelle de temps courte(de l’ordre de l’heure) et suffisamment sensibles, pour évaluer le pouvoir entartrant des eaux. Lors de la thèse, des premières expériences du couplage de la mesure de SAXS (diffusion des rayons X aux petits angles) avec la méthode PCR ont également été effectuées, pour des connaissances plus fines sur les mécanismes de formation et de précipitation de carbonate de calcium, constituant majeur du tartre. Ces expériences ont permis d’observer et caractériser in situ les germes de carbonate de calcium de taille nanométrique dans une eau métastable, avant la précipitation homogène, qui jouent très probablement, en tant que précurseurs, un rôle important dans le phénomène d’entartrage

Preparation of silica aerogels with improved mechanical properties and extremely low thermal conductivities through modified sol-gel process

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 90-96).Reported silica aerogels have a thermal conductivity as low as 15 mW/mK. The fragility of silica aerogels, however, makes them impractical for structural applications. The purpose of the study is to improve the ductility of aerogels while retain the low thermal conductivity of silica aerogels. We have established a new synthesis route, a 3-step sol-gel processing method. The method provides better control of the formation of aerogel structures. The produced silica aerogels show much improved ductility compared to conventional methods in literatures. Furthermore, the synthesized silica aerogels have thermal conductivities as low as about 9 mW/mK, which is the lowest in all reported solids. The ultra low thermal conductivity can be explained with nano-scale structures for the silica aerogels, which have been characterized using advanced techniques including BET and SEM. We have further investigated and demonstrated the ability of enhancing mechanical properties of silica aerogels through structure modification using the proposed 3-step sol-gel processing method. The molecular-level synergism between silica particles/clusters and the doped functional materials inverts the relative host-guest roles in the produced aerogel composite, leading to new stronger and more robust low-density materials.by Yanjia Zuo.S.M