Improving Offline Handwritten Digit Recognition Using Concavity-Based Features

This paper examines benefits of using concavity-based structural features in recognition of handwritten digits. An overview of existing concavity features is presented and a new method is introduced. These features are used as complementary features to gradient and chaincode features, both among the best performing features in handwritten digit recognition. Two support vector classifiers (SVCs) are chosen for classification task as the top performers in previous works; SVC with radial basis function (RBF) kernel and the SVC with polynomial kernel. For reference, we also used the k-nearest neighbor (k-NN) classifier. Results are obtained on MNIST, USPS and DIGITS datasets. We also tested dataset independency of various feature vectors by combining different datasets. The introduced feature extraction method gives the best results in majority of tests

Investigating the use of pretrained convolutional neural network on cross-subject and cross-dataset EEG emotion recognition

The electroencephalogram (EEG) has great attraction in emotion recognition studies due to its resistance to deceptive actions of humans. This is one of the most significant advantages of brain signals in comparison to visual or speech signals in the emotion recognition context. A major challenge in EEG-based emotion recognition is that EEG recordings exhibit varying distributions for different people as well as for the same person at different time instances. This nonstationary nature of EEG limits the accuracy of it when subject independency is the priority. The aim of this study is to increase the subject-independent recognition accuracy by exploiting pretrained state-of-the-art Convolutional Neural Network (CNN) architectures. Unlike similar studies that extract spectral band power features from the EEG readings, raw EEG data is used in our study after applying windowing, pre-adjustments and normalization. Removing manual feature extraction from the training system overcomes the risk of eliminating hidden features in the raw data and helps leverage the deep neural network’s power in uncovering unknown features. To improve the classification accuracy further, a median filter is used to eliminate the false detections along a prediction interval of emotions. This method yields a mean cross-subject accuracy of 86.56% and 78.34% on the Shanghai Jiao Tong University Emotion EEG Dataset (SEED) for two and three emotion classes, respectively. It also yields a mean cross-subject accuracy of 72.81% on the Database for Emotion Analysis using Physiological Signals (DEAP) and 81.8% on the Loughborough University Multimodal Emotion Dataset (LUMED) for two emotion classes. Furthermore, the recognition model that has been trained using the SEED dataset was tested with the DEAP dataset, which yields a mean prediction accuracy of 58.1% across all subjects and emotion classes. Results show that in terms of classification accuracy, the proposed approach is superior to, or on par with, the reference subject-independent EEG emotion recognition studies identified in literature and has limited complexity due to the elimination of the need for feature extraction.<br

Argumentation for Knowledge Representation, Conflict Resolution, Defeasible Inference and Its Integration with Machine Learning

Modern machine Learning is devoted to the construction of algorithms and computational procedures that can automatically improve with experience and learn from data. Defeasible argumentation has emerged as sub-topic of artificial intelligence aimed at formalising common-sense qualitative reasoning. The former is an inductive approach for inference while the latter is deductive, each one having advantages and limitations. A great challenge for theoretical and applied research in AI is their integration. The first aim of this chapter is to provide readers informally with the basic notions of defeasible and non-monotonic reasoning. It then describes argumentation theory, a paradigm for implementing defeasible reasoning in practice as well as the common multi-layer schema upon which argument-based systems are usually built. The second aim is to describe a selection of argument-based applications in the medical and health-care sectors, informed by the multi-layer schema. A summary of the features that emerge from the applications under review is aimed at showing why defeasible argumentation is attractive for knowledge-representation, conflict resolution and inference under uncertainty. Open problems and challenges in the field of argumentation are subsequently described followed by a future outlook in which three points of integration with machine learning are proposed

Atlantic halibut (Hippoglossus hippoglossus L.) fry mortality after transportation with focus on biological and chemical aspects

This thesis is a project finalizing Bachelor of Science degrees in the fields of biological chemistry and chemical- & environmental engineering. As the literature database for Atlantic halibut fish farming is scarce, the need for research is evident and potentially innovative. The intention for this thesis was to show initiative contacting a company within the common field of interest that is fish farming and establish a mutually positive project. As a response to inquiry, Sterling White Halibut (SWH) presented a current problem that was very intriguing and relevant in an educative regard. The thesis project was designed in collaboration with SWH. The focus areas for monitoring were biological stress and water chemistry. Hippoglossus hippoglossus fry (6.70 ± 2.35 g) was transported approximately one thousand kilometers from Rørvik to Imsland. This thesis concerns one batch of 94 186 Atlantic halibut fry, with arrival at Imsland in March 2021. Measurements were made upon arrival and for one month after delivery. SWH reports that a late onset mortality occurs after transportation of small fry sent from the hatchery to the rearing facilities. Some fry batches have endured substantial mortality which is considered caused by the transportation and transfer of fry. The complex phenomenon of late onset mortality after transportation required investigation. Water sampling and chemical analysis were performed in two stages. First stage was at arrival. Analysis of transportation water compared to receiving water presented a relatively large difference in water quality. The second stage was comprised of daily analysis of the water quality to monitor changes during the expected period of mortality. These differences were relatively minor. Biological parameters were measured at arrival and monitored afterwards on each of the three field excursions to complement the water quality data. These datasets served as the basis for the graphical- and statistical analysis. Mortality was considered the prime biological parameter of which the other data were evaluated against. Correlation (r = -0.44) between pH and mortality was discovered and 19 % of the variation observed is explained by the regression model of pH and mortality. Abrupt environmental differences in transportation water compared to receiving water was revealed, which contributes to additional stress after transportation. Stress levels were indicated by elevated blood glucose concentration and increased red blood cell (RBC) count. Late onset mortality is suggested as a consequence of stress during and after transportation, including an unsuccessful adaptation to a new environment at the rearing facilities.This thesis is a project finalizing Bachelor of Science degrees in the fields of biological chemistry and chemical- & environmental engineering. As the literature database for Atlantic halibut fish farming is scarce, the need for research is evident and potentially innovative. The intention for this thesis was to show initiative contacting a company within the common field of interest that is fish farming and establish a mutually positive project. As a response to inquiry, Sterling White Halibut (SWH) presented a current problem that was very intriguing and relevant in an educative regard. The thesis project was designed in collaboration with SWH. The focus areas for monitoring were biological stress and water chemistry. Hippoglossus hippoglossus fry (6.70 ± 2.35 g) was transported approximately one thousand kilometers from Rørvik to Imsland. This thesis concerns one batch of 94 186 Atlantic halibut fry, with arrival at Imsland in March 2021. Measurements were made upon arrival and for one month after delivery. SWH reports that a late onset mortality occurs after transportation of small fry sent from the hatchery to the rearing facilities. Some fry batches have endured substantial mortality which is considered caused by the transportation and transfer of fry. The complex phenomenon of late onset mortality after transportation required investigation. Water sampling and chemical analysis were performed in two stages. First stage was at arrival. Analysis of transportation water compared to receiving water presented a relatively large difference in water quality. The second stage was comprised of daily analysis of the water quality to monitor changes during the expected period of mortality. These differences were relatively minor. Biological parameters were measured at arrival and monitored afterwards on each of the three field excursions to complement the water quality data. These datasets served as the basis for the graphical- and statistical analysis. Mortality was considered the prime biological parameter of which the other data were evaluated against. Correlation (r = -0.44) between pH and mortality was discovered and 19 % of the variation observed is explained by the regression model of pH and mortality. Abrupt environmental differences in transportation water compared to receiving water was revealed, which contributes to additional stress after transportation. Stress levels were indicated by elevated blood glucose concentration and increased red blood cell (RBC) count. Late onset mortality is suggested as a consequence of stress during and after transportation, including an unsuccessful adaptation to a new environment at the rearing facilities

Atlantic halibut (Hippoglossus hippoglossus L.) fry mortality after transportation with focus on biological and chemical aspects

This thesis is a project finalizing Bachelor of Science degrees in the fields of biological chemistry and chemical- & environmental engineering. As the literature database for Atlantic halibut fish farming is scarce, the need for research is evident and potentially innovative. The intention for this thesis was to show initiative contacting a company within the common field of interest that is fish farming and establish a mutually positive project. As a response to inquiry, Sterling White Halibut (SWH) presented a current problem that was very intriguing and relevant in an educative regard. The thesis project was designed in collaboration with SWH. The focus areas for monitoring were biological stress and water chemistry. Hippoglossus hippoglossus fry (6.70 ± 2.35 g) was transported approximately one thousand kilometers from Rørvik to Imsland. This thesis concerns one batch of 94 186 Atlantic halibut fry, with arrival at Imsland in March 2021. Measurements were made upon arrival and for one month after delivery. SWH reports that a late onset mortality occurs after transportation of small fry sent from the hatchery to the rearing facilities. Some fry batches have endured substantial mortality which is considered caused by the transportation and transfer of fry. The complex phenomenon of late onset mortality after transportation required investigation. Water sampling and chemical analysis were performed in two stages. First stage was at arrival. Analysis of transportation water compared to receiving water presented a relatively large difference in water quality. The second stage was comprised of daily analysis of the water quality to monitor changes during the expected period of mortality. These differences were relatively minor. Biological parameters were measured at arrival and monitored afterwards on each of the three field excursions to complement the water quality data. These datasets served as the basis for the graphical- and statistical analysis. Mortality was considered the prime biological parameter of which the other data were evaluated against. Correlation (r = -0.44) between pH and mortality was discovered and 19 % of the variation observed is explained by the regression model of pH and mortality. Abrupt environmental differences in transportation water compared to receiving water was revealed, which contributes to additional stress after transportation. Stress levels were indicated by elevated blood glucose concentration and increased red blood cell (RBC) count. Late onset mortality is suggested as a consequence of stress during and after transportation, including an unsuccessful adaptation to a new environment at the rearing facilities.This thesis is a project finalizing Bachelor of Science degrees in the fields of biological chemistry and chemical- & environmental engineering. As the literature database for Atlantic halibut fish farming is scarce, the need for research is evident and potentially innovative. The intention for this thesis was to show initiative contacting a company within the common field of interest that is fish farming and establish a mutually positive project. As a response to inquiry, Sterling White Halibut (SWH) presented a current problem that was very intriguing and relevant in an educative regard. The thesis project was designed in collaboration with SWH. The focus areas for monitoring were biological stress and water chemistry. Hippoglossus hippoglossus fry (6.70 ± 2.35 g) was transported approximately one thousand kilometers from Rørvik to Imsland. This thesis concerns one batch of 94 186 Atlantic halibut fry, with arrival at Imsland in March 2021. Measurements were made upon arrival and for one month after delivery. SWH reports that a late onset mortality occurs after transportation of small fry sent from the hatchery to the rearing facilities. Some fry batches have endured substantial mortality which is considered caused by the transportation and transfer of fry. The complex phenomenon of late onset mortality after transportation required investigation. Water sampling and chemical analysis were performed in two stages. First stage was at arrival. Analysis of transportation water compared to receiving water presented a relatively large difference in water quality. The second stage was comprised of daily analysis of the water quality to monitor changes during the expected period of mortality. These differences were relatively minor. Biological parameters were measured at arrival and monitored afterwards on each of the three field excursions to complement the water quality data. These datasets served as the basis for the graphical- and statistical analysis. Mortality was considered the prime biological parameter of which the other data were evaluated against. Correlation (r = -0.44) between pH and mortality was discovered and 19 % of the variation observed is explained by the regression model of pH and mortality. Abrupt environmental differences in transportation water compared to receiving water was revealed, which contributes to additional stress after transportation. Stress levels were indicated by elevated blood glucose concentration and increased red blood cell (RBC) count. Late onset mortality is suggested as a consequence of stress during and after transportation, including an unsuccessful adaptation to a new environment at the rearing facilities

Formalising Human Mental Workload as a Defeasible Computational Concept

Human mental workload has gained importance, in the last few decades, as a fundamental design concept in human-computer interaction. It can be intuitively defined as the amount of mental work necessary for a person to complete a task over a given period of time. For people interacting with interfaces, computers and technological devices in general, the construct plays an important role. At a low level, while processing information, often people feel annoyed and frustrated; at higher level, mental workload is critical and dangerous as it leads to confusion, it decreases the performance of information processing and it increases the chances of errors and mistakes. It is extensively documented that either mental overload or underload negatively affect performance. Hence, designers and practitioners who are ultimately interested in system or human performance need answers about operator workload at all stages of system design and operation. At an early system design phase, designers require some explicit model to predict the mental workload imposed by their technologies on end-users so that alternative system designs can be evaluated. However, human mental workload is a multifaceted and complex construct mainly applied in cognitive sciences. A plethora of ad-hoc definitions can be found in the literature. Generally, it is not an elementary property, rather it emerges from the interaction between the requirements of a task, the circumstances under which it is performed and the skills, behaviours and perceptions of the operator. Although measuring mental workload has advantages in interaction and interface design, its formalisation as an operational and computational construct has not sufficiently been addressed. Many researchers agree that too many ad-hoc models are present in the literature and that they are applied subjectively by mental workload designers thereby limiting their application in different contexts and making comparison across different models difficult. This thesis introduces a novel computational framework for representing and assessing human mental workload based on defeasible reasoning. The starting point is the investigation of the nature of human mental workload that appears to be a defeasible phenomenon. A defeasible concept is a concept built upon a set of arguments that can be defeated by adding additional arguments. The word ‘defeasible’ is inherited from defeasible reasoning, a form of reasoning built upon reasons that can be defeated. It is also known as non-monotonic reasoning because of the technical property (non-monotonicity) of the logical formalisms that are aimed at modelling defeasible reasoning activity. Here, a conclusion or claim, derived from the application of previous knowledge, can be retracted in the light of new evidence. Formally, state-of-the-art defeasible reasoning models are implemented employing argumentation theory, a multi-disciplinary paradigm that incorporates elements of philosophy, psychology and sociology. It systematically studies how arguments can be built, sustained or discarded in a reasoning process, and it investigates the validity of their conclusions. Since mental workload can be seen as a defeasible phenomenon, formal defeasible argumentation theory may have a positive impact in its representation and assessment. Mental workload can be captured, analysed, and measured in ways that increase its understanding allowing its use for practical activities. The research question investigated here is whether defeasible argumentation theory can enhance the representation of the construct of mental workload and improve the quality of its assessment in the field of human-computer interaction. In order to answer this question, recurrent knowledge and evidence employed in state-of-the-art mental workload measurement techniques have been reviewed in the first place as well as their defeasible and non-monotonic properties. Secondly, an investigation of the state-of-the-art computational techniques for implementing defeasible reasoning has been carried out. This allowed the design of a modular framework for mental workload representation and assessment. The proposed solution has been evaluated by comparing the properties of sensitivity, diagnosticity and validity of the assessments produced by two instances of the framework against the ones produced by two well known subjective mental workload assessments techniques (the Nasa Task Load Index and the Workload Profile) in the context of human-web interaction. In detail, through an empirical user study, it has been firstly demonstrated how these two state-of-the-art techniques can be translated into two particular instances of the framework while still maintaining the same validity. In other words, the indexes of mental workload inferred by the two original instruments, and the ones generated by their corresponding translations (instances of the framework) showed a positive and nearly perfect statistical correlation. Additionally, a new defeasible instance built with the framework showed a better sensitivity and a higher diagnosticity capacity than the two selected state-of-the art techniques. The former showed a higher convergent validity with the latter techniques, but a better concurrent validity with performance measures. The new defeasible instance generated indexes of mental workload that better correlated with the objective time for task completion compared to the two selected instruments. These findings support the research question thereby demonstrating how defeasible argumentation theory can be successfully adopted to support the representation of mental workload and to enhance the quality of its assessments. The main contribution of this thesis is the presentation of a methodology, developed as a formal modular framework, to represent mental workload as a defeasible computational concept and to assess it as a numerical usable index. This research contributes to the body of knowledge by providing a modular framework built upon defeasible reasoning and formalised through argumentation theory in which workload can be optimally measured, analysed, explained and applied in different contexts

Nimentunnistusjärjestelmän testauksen automatisointi

Software testing is an essential part of the software development process. It is needed to ensure the quality of software. As the software development process is changing towards continuous integration and deployment, an increase in the level of automation in testing is needed to ensure software quality all the time. Using artificial intelligence (AI) creates additional challenges for testing. For instance, it can be challenging to determine whether the test output is unequivocally correct or not. In some cases, the tester can determine that AI software works correctly by using his own judgment or by getting the information from the product owner or the customer. However, in more challenging testing tasks with test automation, it needs to be very accurately specified what the correct output is and what is not. This thesis is about implementing test automation for a named entity recognition system that recognizes person and organization names from text. Named entity recognition is a subcategory of AI. It means aiming to find and classify named entities in text into pre-defined categories like person and organization names. In cases of that kind, the correct outputs can be determined by people

Les cténophores : de leur position dans l'arbre des métazoaires (approche phylogénomique) à leur diversité taxonomique (phylogénie moléculaire et anatomie comparée)

Ctenophores are one of the four animal phyla positioned outside from the Bilateria. Most ctenophore species are planktonic and gelatinous, and are easily recognisable by their eight comb rows used for swimming. Ctenophore systematics remains nowadays poorly understood. Anatomical characters do not help much in placing them within the animal tree, and similarly the grounds for establishment of their internal phylogeny as well as delimitation of species are notoriously weak due to a paucity of informative morpho-anatomical characters. Until now, the use of molecular data has failed to improve significantly this situation. The aim of this PhD thesis was to bring a contribution to our understanding of ctenophore evolution at different taxonomic scales. At the metazoan level, the position of ctenophores was addressed using a phylogenomic approach. Taxonomic sampling was significantly improved through sequencing and assembly of transcriptomes of 22 non-bilaterian species (belonging to ctenophores, cnidarians and sponges). Two independent datasets were analysed, one consisting in an update of an existing supermatrix of 128 genes, the other one (4235 genes) having been entirely built de novo, thanks to a newly-devised semi-automated protocol intended to eliminate all major potential causes of artefacts (contaminations, paralogies, missing data). Results clearly contradict recent phylogenomic studies which claimed Ctenophora to be the most early-diverging animal lineage, our analyses instead supporting Porifera as the sister-group to other metazoans. The exact position of ctenophores remains however uncertain at this stage, different conditions of analyses yielding three contradictory hypotheses as open possibilities. At the intra-phyletic level, analyses of a ADNr 18S and ITS (internal transcribed spacers) dataset, together with study of duplicated genes and the results of phylogenomic analyses, allowed resolving most phylogenetic relationships between ctenophore orders and families, including the placement of the ctenophore tree root. Finally, at smaller taxonomic scale, in-depth comparison between two species of the genus Pleurobrachia using immunohistochemistry demonstrates the potential of these techniques for uncovering new structural “micro-anatomical” characters useful for diagnosis and identification of ctenophore species. It is our hope that this work will contribute to improving the systematics of a poorly known phylum of great importance for understanding early animal evolution.Les cténophores représentent l’un des quatre embranchements animaux extérieurs aux Bilateria. La majoritédes espèces sont planctoniques et gélatineuses, et sont reconnaissables à leurs huit rangées de peignes dont lebattement permet la nage. Leur systématique est encore de nos jours mal comprise. L'anatomie descténophores offre peu de caractères aussi bien pour placer la lignée dans l’arbre des métazoaires, que pourétablir les relations de parenté au sein de l’embranchement et délimiter les espèces, et jusqu’à présent lesdonnées moléculaires n’ont pas permis de résoudre ces problèmes de manière satisfaisante. L’objectif de cetravail de thèse est de contribuer à améliorer notre compréhension de l'évolution des cténophores àdifférentes échelles taxonomiques. A l’échelle des métazoaires, la position phylogénétique des cténophores aété abordée par une approche phylogénomique. Un effort significatif a été réalisé pour améliorerl’échantillonnage taxonomique à travers le séquençage et l’assemblage des transcriptomes de 22 espèces denon-Bilateria (cténophores, cnidaires, spongiaires). Deux jeux de données indépendants ont été analysés, lepremier représentant une mise à jour d’une supermatrice existante de 128 gènes ; le second (4235 gènes)ayant été entièrement construit de novo via un protocole original comportant la mise au point de nouvellesméthodes pour traiter de manière semi-automatisée les principales sources potentielles d’artéfact(contaminations, paralogies, données manquantes). Les résultats contredisent certaines études récentes enmontrant que les spongiaires et non les cténophores représentent le groupe-frère des autres métazoaires. Laposition exacte de ces derniers reste à ce stade incertaine (trois options se présentant suivant les analyses). Al’échelle intra-phylétique, l'analyse d'un jeu de données comprenant les marqueurs ADNr 18S et InternalTranscribed Spacers (ITS), associée à des analyses de gènes dupliqués chez les cténophores et aux analysesphylogénomiques précédentes, a permis de résoudre une grande partie des relations phylogénétiques entre lesordres et les familles de cténophores, tout en permettant de préciser la position de la racine. Enfin, à uneéchelle taxonomique plus fine, une comparaison approfondie entre deux espèces du genre Pleurobrachia aumoyen de marquages immunohistochimiques montre le potentiel de ces techniques comme source denouveaux caractères structuraux « micro-anatomiques » à valeur diagnostique pour la délimitation etl’identification des espèces de cténophores. En conclusion, ce travail se veut une contribution au progrès dela systématique d’un embranchement encore méconnu et d’une grande importance pour la compréhensiondes évènements anciens de l’évolution animale