Computational Fluid Dynamics (CFD) is a main field that contributes to the development of high efficiency aircraft. CFD accuracy depends on the flow solver and the meshing of the geometry, and while it is doable to determine why a certain solver is more accurate than another, it is much more difficult to discern why two meshes produce differently accurate solutions. A framework is presented to evaluate the performance or ``goodness" of a mesh and to compare meshes. The framework is composed of quantifiable mesh parameters which define a mesh, and three performance measures: functional accuracy, their order of convergence, and their behaviour under the adjoint correction method. Although it seems that the relationships between parameters and results are not trivial, there are trends from which optimal mesh parameters are deduced. The H topology performs best, and the most important parameters are related to spacings and cell quality around the aerofoil leading edge.

Today's high-throughput data collection devices, e.g. spectrometers and gene chips, create information in abundance. However, this poses serious statistical challenges, as the number of features is usually much larger than the number of observed units.  Further, in this high-dimensional setting, only a small fraction of the features are likely to be informative for any specific project. In this thesis, three different approaches to the two-class supervised classification in this high-dimensional, low sample setting are considered. There are classifiers that are known to mitigate the issues of high-dimensionality, e.g. distance-based classifiers such as Naive Bayes. However, these classifiers are often computationally intensive and therefore less time-consuming for discrete data. Hence, continuous features are often transformed into discrete features. In the first paper, a discretization algorithm suitable for high-dimensional data is suggested and compared with other discretization approaches. Further, the effect of discretization on misclassification probability in high-dimensional setting is evaluated.   Linear classifiers are more stable which motivate adjusting the linear discriminant procedure to high-dimensional setting. In the second paper, a two-stage estimation procedure of the inverse covariance matrix, applying Lasso-based regularization and Cuthill-McKee ordering is suggested. The estimation gives a block-diagonal approximation of the covariance matrix which in turn leads to an additive classifier. In the third paper, an asymptotic framework that represents sparse and weak block models is derived and a technique for block-wise feature selection is proposed.      Probabilistic classifiers have the advantage of providing the probability of membership in each class for new observations rather than simply assigning to a class. In the fourth paper, a method is developed for constructing a Bayesian predictive classifier. Given the block-diagonal covariance matrix, the resulting Bayesian predictive and marginal classifier provides an efficient solution to the high-dimensional problem by splitting it into smaller tractable problems. The relevance and benefits of the proposed methods are illustrated using both simulated and real data. / Med dagens teknik, till exempel spektrometer och genchips, alstras data i stora mängder. Detta överflöd av data är inte bara till fördel utan orsakar även vissa problem, vanligtvis är antalet variabler (p) betydligt fler än antalet observation (n). Detta ger så kallat högdimensionella data vilket kräver nya statistiska metoder, då de traditionella metoderna är utvecklade för den omvända situationen (p<n).  Dessutom är det vanligtvis väldigt få av alla dessa variabler som är relevanta för något givet projekt och styrkan på informationen hos de relevanta variablerna är ofta svag. Därav brukar denna typ av data benämnas som gles och svag (sparse and weak). Vanligtvis brukar identifiering av de relevanta variablerna liknas vid att hitta en nål i en höstack. Denna avhandling tar upp tre olika sätt att klassificera i denna typ av högdimensionella data.  Där klassificera innebär, att genom ha tillgång till ett dataset med både förklaringsvariabler och en utfallsvariabel, lära en funktion eller algoritm hur den skall kunna förutspå utfallsvariabeln baserat på endast förklaringsvariablerna. Den typ av riktiga data som används i avhandlingen är microarrays, det är cellprov som visar aktivitet hos generna i cellen. Målet med klassificeringen är att med hjälp av variationen i aktivitet hos de tusentals gener (förklaringsvariablerna) avgöra huruvida cellprovet kommer från cancervävnad eller normalvävnad (utfallsvariabeln). Det finns klassificeringsmetoder som kan hantera högdimensionella data men dessa är ofta beräkningsintensiva, därav fungera de ofta bättre för diskreta data. Genom att transformera kontinuerliga variabler till diskreta (diskretisera) kan beräkningstiden reduceras och göra klassificeringen mer effektiv. I avhandlingen studeras huruvida av diskretisering påverkar klassificeringens prediceringsnoggrannhet och en mycket effektiv diskretiseringsmetod för högdimensionella data föreslås. Linjära klassificeringsmetoder har fördelen att vara stabila. Nackdelen är att de kräver en inverterbar kovariansmatris och vilket kovariansmatrisen inte är för högdimensionella data. I avhandlingen föreslås ett sätt att skatta inversen för glesa kovariansmatriser med blockdiagonalmatris. Denna matris har dessutom fördelen att det leder till additiv klassificering vilket möjliggör att välja hela block av relevanta variabler. I avhandlingen presenteras även en metod för att identifiera och välja ut blocken. Det finns också probabilistiska klassificeringsmetoder som har fördelen att ge sannolikheten att tillhöra vardera av de möjliga utfallen för en observation, inte som de flesta andra klassificeringsmetoder som bara predicerar utfallet. I avhandlingen förslås en sådan Bayesiansk metod, givet den blockdiagonala matrisen och normalfördelade utfallsklasser. De i avhandlingen förslagna metodernas relevans och fördelar är visade genom att tillämpa dem på simulerade och riktiga högdimensionella data.

One hundred and eleven mother-child dyads visited the laboratory when children were 10 to 12 years old and again two years later. Children’s self-disclosure to mothers and mothers’ accurate knowledge of effective comforting strategies were examined together in the context of maternal warmth and children’s positive coping. Maternal warmth longitudinally predicted children’s disclosure, and children’s disclosure longitudinally predicted mothers’ accurate knowledge of comforting strategies. Maternal warmth moderated the association between mothers’ accurate knowledge of comforting strategies and children’s positive coping. Specifically, maternal knowledge predicted child coping only in children of cold mothers. Implications for the socialization of coping and the role of child disclosure and parents’ accurate knowledge in parenting interventions are discussed.

Darbo tikslas - nustatyti nenutrūkstamų izometrinių susitraukimų tikslumo ir stabilumo valdymo ypatumus. Tyrimo metu kelti šie uždaviniai: 1) nustatyti ir palyginti vaizdinės grįžtamosios informacijos (VGI) ir skirtingos procentinės jėgos (SPJ) įtaką nenutrūkstamo izometrinio susitraukimo tikslumui, stabilumui ir raumenų (agonisto ir antagonisto) elektriniam aktyvumui; 2) nustatyti ir palyginti mokymosi ir potencijuojamojo krūvio įtaką nenutrūkstamo izometrinio susitraukimo tikslumui ir stabilumui. Buvo tiriami jauni, fiziškai aktyvūs vyrai (n = 8; amžius 20,0 ± 1,5 m, ūgis 182,4 ± 6,5 cm; kūno masė 73,0 ± 5,7 kg, KMI kūno masės indeksas 22,0 ± 1,7 kg/m2 (vid. ± S). Pirmojo tyrimo metu tiriamieji atliko 20%, 50% ir 70% nuo MVJ nenutrūkstamus izometrinius susitraukimus (NIS). Tiriamieji atliko 2 NIS su ir be VGI. NIS truko 13 s, tačiau buvo analizuojami tik paskutinių 10 s duomenys, nes per pirmas 3 s tiriamiesiems buvo leidžiama pasiekti reikiamą jėgą nuo MVJ ir ją išlaikyti likusias 10 s. Antrojo tyrimo metu tiriamieji atliko tokius pačius NIS kaip ir pirmojo tyrimo metu 20% jėga nuo MVJ. Tiriamieji po su VGI ir be jos atliktų NIS atliko rankos raumenų potenciaciją, kurios metu turėjo padidinti rankos lenkimo jėgą iki maksimumo ir ją išlaikyti 10 s. Pailsėję 10 s vėl atliko NIS be VGI. Visas tyrimas buvo pakartotas po 9 - erių mokymosi pratybų, kai per pratybas tiriamieji buvo mokomi atlikti greitus ir tikslius izometrinius susitraukimus 20% jėga nuo MVJ kas antrą dieną su... [toliau žr. visą tekstą] / Research aim was to establish the peculiarities of control of the accuracy and the stability of continuous isometric muscle contractions. Objectives: 1) to establish and compare effect of visual feedback on the accuracy, stability and muscle activity of continuous isometric contractions performed with different strength; 2) to establish and compare effect of learning on the dependence of accuracy and stability of a continuous isometric contraction on muscle potentiation. The subjects studied were healthy, physically active men (n = 8; age 20.0 ± 1.5 m, height 182.4 ± 6.5 cm; body mass 73.0 ± 5.7 kg, body mass index 22.0 ± 1.7 kg/m2 ( ±SD). In experiment 1, the subjects performed CIC at 20%, 50% and 70% force of MVC. The subjects performed two series of CIC – first with visual feedback information (VFI), second – without VFI. The duration of each series was 13 sec. In experiment 2, the subjects performed the same CIC at 20% force of MVC. The subjects after two series of CIC (first with VFI, second – without VFI), done potentiation load (PL), when they had to achieve maximal force and it maintain 10 sec. After 10 sec rest the subjects performed CIC without VFI. All the experiment was repeated after 9 training series. In training series, they were learning speeds – accuracy isometric contractions at 20% force of MVC. Absence of visual feedback information worsening in the accuracy of performing CIC at all forces of MVC. We have established that there is a significant... [to full text]

Tyrime buvo ištirta elektroninio ir indukcinio elektros energijos skaitiklių paklaidų priklausomybė nuo apkrovos stiprio, galios koeficiento ir tinklo įtampos. Tyrimui atlikti buvo naudojamas elektros energijos skaitiklių analizatorius CALPORT 100, kurio tikslumo klasė 0,2. Nustatyta, kad padidėjus tinklo įtampai 10-čia voltų elektroninio elektros energijos skaitiklio paklaida padidėja apie 0,1 %, o indukcinio sumažėja apie 0,065 %. Didžiausi paklaidų pokyčiai abiejų tipų skaitikliuose pastebėti palaikant mažiausias nuo 0,25 A iki 3 A apkrovas. Apkrovos galios koeficiento sumažėjimas nuo 1,0 iki 0,7, esant standartiniai 230 V tinklo įtampai, sukėlė ženklų abiejų tipų skaitiklių neigiamų paklaidų padidėjimą iki -3,48 % elektroniniam skaitikliui ir -3,85 % indukciniam skaitikliui. Didžiausios paklaidos buvo užfiksuotos esant didžiausiai tinklo įtampai 260 V ir mažiausiai galios koeficiento reikšmei 0,7, tuo metu elektroninio skaitiklio santykinė paklaida siekė -4,55 %, o indukcinio -5,32 %. / The aim of this study - to investigate the relation between accuracy of electrical meters and voltage, load and power factor variations. Experiments were performed with electronic and induction type electrometers. Examinations were carried out with electricity meter analyzer CALPORT100. It was found that the increase in voltage of 10 volts here an electricity meter error increases to about 0.1%, while induction by about 0,065%. The largest variations in the two types of meters observed in maintaining the minimum from 0.25 A to 3 A loads. The load power factor decreased from 1.0 to 0.7, with standard 230 V mains voltage, confounding both counters negative bias increases to -3.48% for the electronic meter and meter induction -3,85%. Maximum error was recorded at the maximum voltage of 260 V and a minimum power factor 0.7, while the electronic meter relative error was -4.55% and -5.32% induction.

Magistro baigiamajame darbe išanalizuota ir įvertinta tarptautinė valiutų rinka, jos struktūra bei analizės ir prognozės būdai. Taip pat analizuojami neuronini tinklai bei įvairios jų struktūros: daugiasluoksnis perseptronas, radialinių bazinių funkcijų neuroniniai tinklai, GRNN bei rekurentiniai neuroniniai tinklai. Tyrimu siekiama nustatyti ar valiutų kursų prognozavimo tikslumas, taikant neuroninius tinklus, priklauso nuo investavimo rizikos lygio. Darbas susideda iš trijų skyrių. Pirmame skyriuje nagrinėjama tarptautinės valiutų rinkos teorija, didesnį dėmesį atkreipiant į pačia FOREX koncepciją, rinkos dalyvius bei jų elgesį ir finansinius instrumentus, naudojamus šioje rinkoje. Tiriami pagrindiniai valiutų kursų prognozės bei analizės būdai, skirstant juos fundamentalią ir techninę analizę. Analizė atliekama, tiriant Lietuvos ir užsienio mokslininkų darbus valiutų rinkos prognozavimo srityje. Antrame skyriuje analizuojami neuroniniai tinklai. Aprašoma neuroninių tinklų koncepcija bei taikymo sritys. Naudojant literatūros analizės metodą, tiriami Lietuvos ir užsienio autorių moksliniai darbai, kuriuose aprašomi neuroninių tinklų tyrimai valiutų rinkos prognozavimo srityje. Pateikiama aktualiausių straipsnių meta analizė. Trečiame skyriuje atliekamas tyrimas su pasirinktų tyrimų duomenimis. Aprašomi šių pasirinkimo motyvai. Skyriaus galia pateikti statistiniai analizės rezultatai: MAE (angl. Mean absoliute error), MAPE (angl. Mean absolute percentage error) krypties... [toliau žr. visą tekstą] / The master thesis analyses the application of the neural networks for foreign exchange market forecast. Multilayer perceptron, radial basis functionneural networks, GRNN and recurrent neural networks are analyzed in order to find the correlation level between the forecast accuracy and the level of the investment risk. The work consists of three main parts. The first part analyses the conception, the main participants, trading characteristics and trading instruments of the FOREX market as well as the trading strategies and the methods of forecasting currency market. The second part is appointed to analyze the neural networks. The analyzes the conception, the structure and the application of the neural networks is made. The Meta-analyses of the main scientific articles are provided in every sub-part. In the third part the forecasting data analysis is performed to evaluate the correlation rate between the forecast accuracy and the level of the investment risk. Mean absolute error, Mean absolute percentage error, sign function andStandard deviation are used as indicators.

To date, research on the effect of depressive symptomatology on victim-witness identification is scarce even though depressive symptomatology is highly prevalent in the victim-witness experience. Furthermore, being a victim-witness often instigates the use of counselling services, which could cause a shift in affect, and applying mood dependent memory theories, any change in affect should be detrimental to eyewitness accuracy. Still, individuals suffering from subclinical depression, or dysphoria, have exhibited heightened perceptual skills, and depressed affect exhibits remarkable stability over time. Therefore, I theorized that: (1) dysphoric people’s heightened sensitivity and motivation towards accurate understanding may result in more accurate eyewitness identifications, and (2) individuals who express stable levels of dysphoria should have greater eyewitness identification accuracy than should people with stable levels of nondysphoria, with stable levels of severe depressive symptomatology, or with unstable depressive symptomatology. In Study One, 132 students were randomly assigned to one of three autobiographical mood inductions: a positive, negative, or neutral/control. Following this manipulation, participants completed 12 experimental trials each consisting of a target exposure, a 30-second distraction task, and lastly, a six-person simultaneous line-up. Higher levels of dysphoria were associated with greater overall identification accuracy and that temporary mood conferred an advantage only when participants recalled highly sad memories. In Study Two, 173 participants were exposed to 12 target faces at a first session and returned two-to-four weeks later to identify these faces from 12 six-person simultaneous line-ups. Individuals who exhibited stable levels of dysphoria from eyewitness event to the line-up task performed significantly better on the simultaneous line-ups than all of the other groups. Among those exhibiting unstable dysphoria, people whose depressive symptomatology improved were almost as accurate as those who had stable dysphoria. These results support the need for victim-witnesses to receive immediate help to stabilize or improve depressive symptomatology not just for their mental well-being but also to preserve eyewitness accuracy. / Thesis (Master, Psychology) -- Queen's University, 2010-09-23 13:11:50.153

No description available.

<p>The aim of this study was to explore the use of play with toddlers who are HIV positive to facilitate play, playfulness and sensory-motor development. The objectives were to explore how the therapist facilitated play, to explore how the child responded to the intervention, to explore how playfulness manifested as a facilitatory strategy and to explore how playfulness manifested as a response. A qualitative approach framed the case study research method with three participants between the ages of twelve months and three years. The main source of data was a record of the play-based intervention with the three participants. Additional data was obtained from participant observation of the children&rsquo / s responses to the play-based intervention, and hospital and occupational therapy record notes. A theory analytical strategy was used by coding data using theoretic propositions inductively. Each case was first analyzed individually, and then an analysis was made across the cases. Qualitative analysis of the data was done manually by coding, seeking categories and eliciting emergent themes by using an analytical strategy of theoretical propositions and an analytical technique of explanation building. Coding was done inductively, using theoretical constructs from the occupation by design, namely the elements of appeal, intactness and accuracy. Signs of playfulness were coded according to evidence of the elements of playfulness, namely perception of control, intrinsic motivation, suspension of reality or framing were evident in the data. Findings of the study were reported under two themes: Playful enablement &ndash / the therapist and Engaging, playing and developing &ndash / the child.</p>

Au cours des dernières années, il a été démontré que la façon dont la douleur est communiquée, par l’entremise de comportements de douleur, est associée à l’incapacité auto-rapportée et à la trajectoire de chronicité des individus souffrant de douleur persistante. Cependant, très peu de recherches ont investigué le lien entre la perception de la douleur dans le couple et la trajectoire de chronicité des individus souffrant de douleur persistante. Dans le cadre de cette thèse, trois études ont été réalisées afin de mieux comprendre les facteurs impliqués dans la communication de la douleur au sein de couples dont l’un des partenaires souffrait de douleur persistante. Une première étude a été réalisée afin de valider une version francophone du « Pain Disability Index (PDI) », un questionnaire développé pour évaluer l’incapacité reliée à la douleur persistante. Comme attendu, les résultats indiquent que cette version du PDI reproduit la structure factorielle de la version originale du PDI et présente une bonne fidélité et validité. Une autre étude a été réalisée auprès de couples dont l’un des partenaires souffre de douleur persistante afin d’évaluer les corrélats de la justesse empathique, d’explorer la relation entre la justesse empathique reliée à la douleur et différentes variables associées à l’adaptation du patient et du conjoint et enfin d’explorer la relation entre la justesse empathique reliée à la douleur et des variables relationnelles. Les résultats suggèrent que de façon générale, la justesse empathique est associée à des résultats négatifs chez les patients souffrant de douleur persistante et ne semble pas un corrélat important de la satisfaction conjugale. Enfin, une dernière étude a été réalisée afin de comprendre l’influence de la concordance des pensées catastrophiques dans le couple sur l’émission de comportements de douleur et sur la perception de la douleur et de l’incapacité lors d’une tâche physiquement exigeante. Il a été trouvé que les participants ayant un niveau élevé de pensées catastrophiques, qui étaient en relation avec un conjoint ayant un faible niveau de pensées catastrophiques, ont émis plus de comportements de douleur que tous les autres groupes. Ces résultats suggèrent que les personnes souffrant de douleur persistante ayant un niveau élevé de pensées catastrophiques peuvent avoir besoin d’augmenter le « volume » de la communication de la douleur afin de compenser pour la tendance des conjoints ayant un faible niveau de pensées catastrophiques à sous-estimer les signaux de douleur. En résumé, puisque l’émission de comportements de douleur est associée à l’incapacité auto-rapportée des individus souffrant de douleur persistante, il est possible que toute situation qui contribue à une augmentation des comportements de douleur, contribuera également à un niveau d’incapacité plus élevé. Ainsi, d’un point de vue clinique, les interventions qui amènent le conjoint à faire de l’écoute active et à valider la personne souffrante, pourraient réduire la présence des comportements de douleur et potentiellement avoir un impact sur le niveau d’incapacité des personnes souffrant de douleur persistante. / In the past, it has been shown that pain communication, through the display of pain behaviours, is related to self-reported disability and pain chronicity. However, few studies have investigated the link between pain perception in couples and the chronic trajectory of individuals suffering from persistent pain. In the current thesis, three studies were conducted in order to understand the factors that are involved in pain communication in couples where one partner suffers from persistent pain. The first study aimed to validate a francophone version of the Pain Disability Index (PDI), a questionnaire, developed to assess disability associated with persistent pain. As expected, the results showed that this version of the PDI replicate the factorial structure of the original version of the PDI and showed a good reliability and validity. Another study was conducted with couples where one partner suffers from persistent pain to investigate the correlates of empathic accuracy, explore the relation between pain-related empathic accuracy and different variables associated with adaptational outcomes for chronic pain patients and their spouses, and explore the relation between pain-related empathic accuracy and relational variables. The results generally suggest that empathic accuracy is associated with negative outcomes for the patient, and might not be an important correlate of marital satisfaction. Finally, a last study was conducted to understand the influence of couple concordance of catastrophizing on the display of pain behaviours and on the perception of pain and disability in a physically demanding task. Results revealed that high catastrophizing pain participants, who were in a relationship with a low catastrophizing spouse, displayed more pain behaviours than all other groups. These findings suggest that high catastrophizing chronic pain persons might need to increase the ‘volume’ of pain communication in order to compensate for low catastrophizing spouses’ tendency to underestimate the severity of their pain experience. In brief, since the display of pain behaviours is related to self-reported disability of chronic pain persons, it is possible that any situation that contributes to the increase of pain behaviours, will also contribute to a higher disability level. Therefore, from a clinical perspective, interventions that lead the spouse to engage in active listening and to respond with validating statements, could reduce the amount of pain behaviours and possibly have an impact on the disability level of chronic pain persons.