Modelling data and voice traffic over IP networks using continuous-time Markov models

Common approaches to IP-traffic modelling have featured the use of stochastic models, based on the Markov property, which can be classified into black box and white box models based on the approach used for modelling traffic. White box models, are simple to understand, transparent and have a physical meaning attributed to each of the associated parameters. To exploit this key advantage, this thesis explores the use of simple classic continuous-time Markov models based on a white box approach, to model, not only the network traffic statistics but also the source behaviour with respect to the network and application. The thesis is divided into two parts: The first part focuses on the use of simple Markov and Semi-Markov traffic models, starting from the simplest two-state model moving upwards to n-state models with Poisson and non-Poisson statistics. The thesis then introduces the convenient to use, mathematically derived, Gaussian Markov models which are used to model the measured network IP traffic statistics. As one of the most significant contributions, the thesis establishes the significance of the second-order density statistics as it reveals that, in contrast to first-order density, they carry much more unique information on traffic sources and behaviour. The thesis then exploits the use of Gaussian Markov models to model these unique features and finally shows how the use of simple classic Markov models coupled with use of second-order density statistics provides an excellent tool for capturing maximum traffic detail, which in itself is the essence of good traffic modelling. The second part of the thesis, studies the ON-OFF characteristics of VoIP traffic with reference to accurate measurements of the ON and OFF periods, made from a large multi-lingual database of over 100 hours worth of VoIP call recordings. The impact of the language, prosodic structure and speech rate of the speaker on the statistics of the ON-OFF periods is analysed and relevant conclusions are presented. Finally, an ON-OFF VoIP source model with log-normal transitions is contributed as an ideal candidate to model VoIP traffic and the results of this model are compared with those of previously published work.

Knowledge transfer in website design:exploring the processes and benefits of design collaboration for non-creative Micros

This thesis explores the interaction between Micros (<10 employees) from non-creative sectors and website designers ("Creatives") that occurred when creating a website of a higher order than a basic template site. The research used Straussian Grounded Theory Method with a longitudinal design, in order to identify what knowledge transferred to the Micros during the collaboration, how it transferred, what factors affected the transfer and outcomes of the transfer including behavioural additionality. To identify whether the research could be extended beyond this, five other design areas were also examined, as well as five Small to Medium Enterprises (SMEs) engaged in website and branding projects. The findings were that, at the start of the design process, many Micros could not articulate their customer knowledge, and had poor marketing and visual language skills, knowledge core to web design, enabling targeted communication to customers through images. Despite these gaps, most Micros still tried to lead the process. To overcome this disjoint, the majority of the designers used a knowledge transfer strategy termed in this thesis as ‘Bi-Modal Knowledge Transfer’, where the Creative was aware of the transfer but the Micro was unaware, both for drawing out customer knowledge from the Micro and for transferring visual language skills to the Micro. Two models were developed to represent this process. Two models were also created to map changes in the knowledge landscapes of customer knowledge and visual language – the Knowledge Placement Model and the Visual Language Scale. The Knowledge Placement model was used to map the placement of customer knowledge within the consciousness, extending the known Automatic-Unconscious -Conscious model, adding two more locations – Peripheral Consciousness and Occasional Consciousness. Peripheral Consciousness is where potential knowledge is held, but not used. Occasional Consciousness is where potential knowledge is held but used only for specific tasks. The Visual Language Scale was created to measure visual language ability from visually responsive, where the participant only responds personally to visual symbols, to visually multi-lingual, where the participant can use visual symbols to communicate with multiple thought-worlds. With successful Bi-Modal Knowledge Transfer, the outcome included not only an effective website but also changes in the knowledge landscape for the Micros and ongoing behavioural changes, especially in marketing. These effects were not seen in the other design projects, and only in two of the SME projects. The key factors for this difference between SMEs and Micros appeared to be an expectation of knowledge by the Creatives and failure by the SMEs to transfer knowledge within the company.

Automatic Identification of False Friends in Parallel Corpora: Statistical and Semantic Approach

False friends are pairs of words in two languages that are perceived as similar but have different meanings. We present an improved algorithm for acquiring false friends from sentence-level aligned parallel corpus based on statistical observations of words occurrences and co-occurrences in the parallel sentences. The results are compared with an entirely semantic measure for cross-lingual similarity between words based on using the Web as a corpus through analyzing the words’ local contexts extracted from the text snippets returned by searching in Google. The statistical and semantic measures are further combined into an improved algorithm for identification of false friends that achieves almost twice better results than previously known algorithms. The evaluation is performed for identifying cognates between Bulgarian and Russian but the proposed methods could be adopted for other language pairs for which parallel corpora and bilingual glossaries are available.

Conceptual Idea of Identification of Patterns and Problem Solving in the Human’s Memory and the Possibilities to Use it in Artificial Intelligent

Given cybernetic idea is formed on the basis of neurophysiologic, neuropsychological, neurocybernetic data and verisimilar hypotheses, which fill gaps of formers, of the author as well. First of all attention is focused on general principles of a Memory organization in the brain and processes which take part in it that realize such psychical functions as perception and identification of input information about patterns and a problem solving, which is specified by the input and output conditions, as well. Realization of the second function, essentially cogitative, is discussed in the aspects of figurative and lingual thinking on the levels of intuition and understanding. The reasons of advisability and principles of bionic approach to creation of appropriate tools of artificial intelligent are proposed.

ASPICO: Advanced Scientific Portal for International Cooperation on Digital Cultural Conten

* This research is partially supported by a grant (bourse Lavoisier) from the French Ministry of Foreign Affairs (Ministère des Affaires Etrangères).

Where do bright ideas occur in our brain? Meta-analytic evidence from neuroimaging studies of domain-specific creativity

Many studies have assessed the neural underpinnings of creativity, failing to find a clear anatomical localization. We aimed to provide evidence for a multi-componential neural system for creativity. We applied a general activation likelihood estimation (ALE) meta-analysis to 45 fMRI studies. Three individual ALE analyses were performed to assess creativity in different cognitive domains (Musical, Verbal, and Visuo-spatial). The general ALE revealed that creativity relies on clusters of activations in the bilateral occipital, parietal, frontal, and temporal lobes. The individual ALE revealed different maximal activation in different domains. Musical creativity yields activations in the bilateral medial frontal gyrus, in the left cingulate gyrus, middle frontal gyrus, and inferior parietal lobule and in the right postcentral and fusiform gyri. Verbal creativity yields activations mainly located in the left hemisphere, in the prefrontal cortex, middle and superior temporal gyri, inferior parietal lobule, postcentral and supramarginal gyri, middle occipital gyrus, and insula. The right inferior frontal gyrus and the lingual gyrus were also activated. Visuo-spatial creativity activates the right middle and inferior frontal gyri, the bilateral thalamus and the left precentral gyrus. This evidence suggests that creativity relies on multi-componential neural networks and that different creativity domains depend on different brain regions.

Neural activity during object perception in schizophrenia patients is associated with illness duration and affective symptoms

Background - Abnormalities in visual processes have been observed in schizophrenia patients and have been associated with alteration of the lateral occipital complex and visual cortex. However, the relationship of these abnormalities with clinical symptomatology is largely unknown. Methods - We investigated the brain activity associated with object perception in schizophrenia. Pictures of common objects were presented to 26 healthy participants (age = 36.9; 11 females) and 20 schizophrenia patients (age = 39.9; 8 females) in an fMRI study. Results - In the healthy sample the presentation of pictures yielded significant activation (pFWE (cluster) < 0.001) of the bilateral fusiform gyrus, bilateral lingual gyrus, and bilateral middle occipital gyrus. In patients, the bilateral fusiform gyrus and bilateral lingual gyrus were significantly activated (pFWE (cluster) < 0.001), but not so the middle occipital gyrus. However, significant bilateral activation of the middle occipital gyrus (pFWE (cluster) < 0.05) was revealed when illness duration was controlled for. Depression was significantly associated with increased activation, and anxiety with decreased activation, of the right middle occipital gyrus and several other brain areas in the patient group. No association with positive or negative symptoms was revealed. Conclusions - Illness duration accounts for the weak activation of the middle occipital gyrus in patients during picture presentation. Affective symptoms, but not positive or negative symptoms, influence the activation of the right middle occipital gyrus and other brain areas.

Improving cross language information retrieval using corpus based query suggestion approach

Users seeking information may not find relevant information pertaining to their information need in a specific language. But information may be available in a language different from their own, but users may not know that language. Thus users may experience difficulty in accessing the information present in different languages. Since the retrieval process depends on the translation of the user query, there are many issues in getting the right translation of the user query. For a pair of languages chosen by a user, resources, like incomplete dictionary, inaccurate machine translation system may exist. These resources may be insufficient to map the query terms in one language to its equivalent terms in another language. Also for a given query, there might exist multiple correct translations. The underlying corpus evidence may suggest a clue to select a probable set of translations that could eventually perform a better information retrieval. In this paper, we present a cross language information retrieval approach to effectively retrieve information present in a language other than the language of the user query using the corpus driven query suggestion approach. The idea is to utilize the corpus based evidence of one language to improve the retrieval and re-ranking of news documents in the other language. We use FIRE corpora - Tamil and English news collections in our experiments and illustrate the effectiveness of the proposed cross language information retrieval approach.

Changes in Brain Resting-state Functional Connectivity Associated with Peripheral Nerve Block: A Pilot Study.

BACKGROUND: Limited information exists on the effects of temporary functional deafferentation (TFD) on brain activity after peripheral nerve block (PNB) in healthy humans. Increasingly, resting-state functional connectivity (RSFC) is being used to study brain activity and organization. The purpose of this study was to test the hypothesis that TFD through PNB will influence changes in RSFC plasticity in central sensorimotor functional brain networks in healthy human participants. METHODS: The authors achieved TFD using a supraclavicular PNB model with 10 healthy human participants undergoing functional connectivity magnetic resonance imaging before PNB, during active PNB, and during PNB recovery. RSFC differences among study conditions were determined by multiple-comparison-corrected (false discovery rate-corrected P value less than 0.05) random-effects, between-condition, and seed-to-voxel analyses using the left and right manual motor regions. RESULTS: The results of this pilot study demonstrated disruption of interhemispheric left-to-right manual motor region RSFC (e.g., mean Fisher-transformed z [effect size] at pre-PNB 1.05 vs. 0.55 during PNB) but preservation of intrahemispheric RSFC of these regions during PNB. Additionally, there was increased RSFC between the left motor region of interest (PNB-affected area) and bilateral higher order visual cortex regions after clinical PNB resolution (e.g., Fisher z between left motor region of interest and right and left lingual gyrus regions during PNB, -0.1 and -0.6 vs. 0.22 and 0.18 after PNB resolution, respectively). CONCLUSIONS: This pilot study provides evidence that PNB has features consistent with other models of deafferentation, making it a potentially useful approach to investigate brain plasticity. The findings provide insight into RSFC of sensorimotor functional brain networks during PNB and PNB recovery and support modulation of the sensory-motor integration feedback loop as a mechanism for explaining the behavioral correlates of peripherally induced TFD through PNB.

Individual Differences in the Neural Response to Personal Goal Pursuit Success and Failure: A Developmental Analysis

Regulatory focus theory (RFT) proposes two different social-cognitive motivational systems for goal pursuit: a promotion system, which is organized around strategic approach behaviors and "making good things happen," and a prevention system, which is organized around strategic avoidance and "keeping bad things from happening." The promotion and prevention systems have been extensively studied in behavioral paradigms, and RFT posits that prolonged perceived failure to make progress in pursuing promotion or prevention goals can lead to ineffective goal pursuit and chronic distress (Higgins, 1997).

Research has begun to focus on uncovering the neural correlates of the promotion and prevention systems in an attempt to differentiate them at the neurobiological level. Preliminary research suggests that the promotion and prevention systems have both distinct and overlapping neural correlates (Eddington, Dolcos, Cabeza, Krishnan, & Strauman, 2007; Strauman et al., 2013). However, little research has examined how individual differences in regulatory focus develop and manifest. The development of individual differences in regulatory focus is particularly salient during adolescence, a crucial topic to explore given the dramatic neurodevelopmental and psychosocial changes that take place during this time, especially with regard to self-regulatory abilities. A number of questions remain unexplored, including the potential for goal-related neural activation to be modulated by (a) perceived proximity to goal attainment, (b) individual differences in regulatory orientation, specifically general beliefs about one's success or failure in attaining the two kinds of goals, (c) age, with a particular focus on adolescence, and (d) homozygosity for the Met allele of the catechol-O-methyltransferase (COMT) Val158Met polymorphism, a naturally occurring genotype which has been shown to impact prefrontal cortex activation patterns associated with goal pursuit behaviors.

This study explored the neural correlates of the promotion and prevention systems through the use of a priming paradigm involving rapid, brief, masked presentation of individually selected promotion and prevention goals to each participant while being scanned. The goals used as priming stimuli varied with regard to whether participants reported that they were close to or far away from achieving them (i.e. a "match" versus a "mismatch" representing perceived success or failure in personal goal pursuit). The study also assessed participants' overall beliefs regarding their relative success or failure in attaining promotion and prevention goals, and all participants were genotyped for the COMT Val158Met polymorphism.

A number of significant findings emerged. Both promotion and prevention priming were associated with activation in regions associated with self-referential cognition, including the left medial prefrontal cortex, cuneus, and lingual gyrus. Promotion and prevention priming were also associated with distinct patterns of neural activation; specifically, left middle temporal gyrus activation was found to be significantly greater during prevention priming. Activation in response to promotion and prevention goals was found to be modulated by self-reports of both perceived proximity to goal achievement and goal orientation. Age also had a significant effect on activation, such that activation in response to goal priming became more robust in the prefrontal cortex and in default mode network regions as a function of increasing age. Finally, COMT genotype also modulated the neural response to goal priming both alone and through interactions with regulatory focus and age. Overall, these findings provide further clarification of the neural underpinnings of the promotion and prevention systems as well as provide information about the role of development and individual differences at the personality and genetic level on activity in these neural systems.

Mandibular Torus : A Synthesis of New and Previously Reported Data and a Discusssion of its Cause

Using original data on 1,5000 mandibles, but mainly previously published data, I present a overview of the distribution characteristics of mandibular torus and a hypothesis concerning its cause. Pedigree studies have established that genetic factors influence torus development. Extrinsic factors are strongly implicated by other evidence: prevalence among Arctic peoples, effect of dietary change, age regression, preponderance in males and on the right side, effect of cranial deformation, concurrence with palatine torus and maxillary alveolar exostoses, and clinical evidence. I propose that the primary factor is masticatory stress. According to a mechanism suggested by orthodontic research, the horizontal component of bite force tips the lower canine, premolars and first molar so that their root apices exert pressure on the periodontal membrane, causing formation of new bone on the lingual cortical plate of the alveolar process. Thus formed, the hyperostosis is vulnerable to trauma and its periosteal covering becomes bruised causing additional deposition of bone. Genes influence torus indirectly through their effect on occlusion. A patern of increased expressivity with incidence suggests that a quasicontinuous model may provide a better fit to pedigree data than single locus models previously tested.

A vueltas con la naturaleza del cambio fonético-fonológico: los casos de Nj y Lj

Las etapas del cambio fonético-fonológico han sido descritas desde hace décadas, especialmente desde un punto de vista articulatorio y casi siempre partiendo de los testimonios escritos de que se podía disponer. No obstante, recientemente han ido surgiendo nuevas teorías que defienden que el cambio puede ser explicado a través del estudio de la variación y los procesos fonéticos propios del habla actual, puesto que ambos están relacionados con fenómenos de hipo (e hiper) articulación y, a la postre, de coarticulación. Una de ellas es la Fonología Evolutiva (Blevins 2004), aun cuando no ofrece una explicación satisfactoria para la difusión del cambio. En este estudio, se ha recurrido a estas teorías para esclarecer las causas de la evolución de dos contextos de yod segunda: /nj/ y /lj/, que llevaron a la fonologización de // y //, en un primer estadio de la historia del español.

ReaderBench goes Online: A Comprehension-Centered Framework for Educational Purposes

In this paper we introduce the online version of our ReaderBench framework, which includes multi-lingual comprehension-centered web services designed to address a wide range of individual and collaborative learning scenarios, as follows. First, students can be engaged in reading a course material, then eliciting their understanding of it; the reading strategies component provides an in-depth perspective of comprehension processes. Second, students can write an essay or a summary; the automated essay grading component provides them access to more than 200 textual complexity indices covering lexical, syntax, semantics and discourse structure measurements. Third, students can start discussing in a chat or a forum; the Computer Supported Collaborative Learning (CSCL) component provides indepth conversation analysis in terms of evaluating each member’s involvement in the CSCL environments. Eventually, the sentiment analysis, as well as the semantic models and topic mining components enable a clearer perspective in terms of learner’s points of view and of underlying interests.

Bilingual Lexical Access in Reading : Analyzing the Effect of Semantic Context on Non-Selective Access in Bilingual Memory

Recent empirical studies about the neurological executive nature of reading in bilinguals differ in their evaluations of the degree of selective manifestation in lexical access as implicated by data from early and late reading measures in the eye-tracking paradigm. Currently two scenarios are plausible: (1) Lexical access in reading is fundamentally language non-selective and top-down effects from semantic context can influence the degree of selectivity in lexical access; (2) Cross-lingual lexical activation is actuated via bottom-up processes without being affected by top-down effects from sentence context. In an attempt to test these hypotheses empirically, this study analyzed reader-text events arising when cognate facilitation and semantic constraint interact in a 22 factorially designed experiment tracking the eye movements of 26 Swedish-English bilinguals reading in their L2. Stimulus conditions consisted of high- and low-constraint sentences embedded with either a cognate or a non-cognate control word. The results showed clear signs of cognate facilitation in both early and late reading measures and in either sentence conditions. This evidence in favour of the non-selective hypothesis indicates that the manifestation of non-selective lexical access in reading is not constrained by top-down effects from semantic context.

Exploration génétique de l'hypothyroïdie congénitale par dysgénésie thyroïdienne

L'hypothyroïdie congénitale par dysgénésie thyroïdienne (HCDT, ectopie dans plus de 80 %) a une prévalence de 1 cas sur 4000 naissances vivantes. L’HCDT est la conséquence d'une défaillance de la thyroïde embryonnaire à se différencier, à se maintenir ou à migrer vers sa localisation anatomique (partie antérieure du cou), qui aboutit à une absence totale de la thyroïde (athyréose) ou à une ectopie thyroïdienne (linguale ou sublinguale). Les HCDT sont principalement non-syndromiques (soit 98% des cas sont non-familiale), ont un taux de discordance de 92% chez les jumeaux monozygotes, et ont une prédominance féminine et ethnique (i.e., Caucasienne). La majorité des cas d’HCDT n’a pas de cause connue, mais est associée à un déficit sévère en hormones thyroïdiennes (hypothyroïdie). Des mutations germinales dans les facteurs de transcription liés à la thyroïde (NKX2.1, FOXE1, PAX8, NKX2.5) ont été identifiées dans seulement 3% des patients atteints d’HCDT sporadiques et l’analyse de liaisons exclue ces gènes dans les rares familles multiplex avec HCDT. Nous supposons que le manque de transmission familiale claire d’HCDT peut résulter de la nécessité d’au moins deux « hits » génétiques différents dans des gènes importants pour le développement thyroïdien. Pour répondre au mieux nos questions de recherche, nous avons utilisé deux approches différentes: 1) une approche gène candidat, FOXE1, seul gène impliqué dans l’ectopie dans le modèle murin et 2) une approche en utilisant les techniques de séquençage de nouvelle génération (NGS) afin de trouver des variants génétiques pouvant expliquer cette pathologie au sein d’une cohorte de patients avec HCDT. Pour la première approche, une étude cas-contrôles a été réalisée sur le promoteur de FOXE1. Il a récemment été découvert qu’une région du promoteur de FOXE1 est différentiellement méthylée au niveau de deux dinucléotides CpG consécutifs, définissant une zone cruciale de contrôle de l’expression de FOXE1. L’analyse d’association basée sur les haplotypes a révélé qu’un haplotype (Hap1: ACCCCCCdel1C) est associé avec le HCDT chez les Caucasiens (p = 5x10-03). Une réduction significative de l’activité luciférase est observée pour Hap1 (réduction de 68%, p<0.001) comparé au promoteur WT de FOXE1. Une réduction de 50% de l’expression de FOXE1 dans une lignée de cellules thyroïdienne humaine est suffisante pour réduire significativement la migration cellulaire (réduction de 55%, p<0.05). Un autre haplotype (Hap2: ACCCCCCC) est observé moins fréquemment chez les Afro-Américain comparés aux Caucasiens (p = 1.7x10-03) et Hap2 diminue l’activité luciférase (réduction de 26%, p<0.001). Deux haplotypes distincts sont trouvés fréquemment dans les contrôles Africains (Black-African descents). Le premier haplotype (Hap3: GTCCCAAC) est fréquent (30.2%) chez les contrôles Afro-Américains comparés aux contrôles Caucasiens (6.3%; p = 2.59 x 10-9) tandis que le second haplotype (Hap4: GTCCGCAC) est trouvé exclusivement chez les contrôles Afro-Américains (9.4%) et est absent chez les contrôles Caucasiens (P = 2.59 x 10-6). Pour la deuxième approche, le séquençage de l’exome de l’ADN leucocytaire entre les jumeaux MZ discordants n’a révélé aucune différence. D'où l'intérêt du projet de séquençage de l’ADN et l’ARN de thyroïdes ectopiques et orthotopiques dans lesquelles de l'expression monoallélique aléatoire dans a été observée, ce qui pourrait expliquer comment une mutation monoallélique peut avoir des conséquences pathogéniques. Finalement, le séquençage de l’exome d’une cohorte de 36 cas atteints d’HCDT a permis d’identifier de nouveaux variants probablement pathogéniques dans les gènes récurrents RYR3, SSPO, IKBKE et TNXB. Ces quatre gènes sont impliqués dans l’adhésion focale (jouant un rôle dans la migration cellulaire), suggérant un rôle direct dans les défauts de migration de la thyroïde. Les essais de migration montrent une forte diminution (au moins 60% à 5h) de la migration des cellules thyroïdiennes infectées par shRNA comparés au shCtrl dans 2 de ces gènes. Des zebrafish KO (-/- et +/-) pour ces nouveaux gènes seront réalisés afin d’évaluer leur impact sur l’embryologie de la thyroïde.