Although anxiety disorders and conduct problems often co-occur in children and adolescents, literature describing the effects of such co-occurrence is mixed. There is evidence that symptoms of anxiety disorders may mitigate symptoms of conduct problems (buffering hypothesis) or may exacerbate symptoms of conduct problems (multiple problem hypothesis). A dual-pathway model has been proposed that suggests several possible etiological or risk processes that may differentiate these pathways (i.e., the buffering hypothesis or the multiple problem hypothesis) (Drabick, Ollendick, & Bubier, 2010). Executive functioning is one factor that has been identified that may differentially confer risk to the proposed pathways; however, little research has been done investigating its role. The purpose of the present study was to evaluate the dual-pathway model by determining whether executive functioning abilities contribute to differentiating those youth for whom anxiety exacerbates conduct problems from those for whom anxiety mitigates conduct problems. Specifically, the study sought to examine if executive functioning moderated the effect of anxiety symptom severity on conduct problems. Latent variable structural equation modeling (SEM) was used to analyze the data of 221 youth aged 9 to 16 in a residential treatment center who completed a full neuropsychological evaluation. Results of the study failed to support the hypothesis that executive functioning moderates the effect of anxiety on conduct problems. Furthermore, a structural equation model without an interaction between executive functioning and anxiety was found to fit the data better than a model with an interaction between those variables. Overall, the study found that executive functioning abilities could not distinguish youth for whom anxiety exacerbates conduct problems from youth for whom anxiety mitigates conduct problems. Recommendations for future research in light of the limitations of the current study, as well as remaining gaps in the literature, are discussed. / text

Deploying wind power to a larger extent is one solution to reduce negative environmental impacts of electric power supply. However, various challenges are connected with increasing wind power penetration levels. From the perspective of transmission system operators, this includes balancing of varying as well as - to some extent - uncertain generation levels. From the perspective of power generating companies, changes in the generation mix will affect the market's merit order and, hence, their profits. This thesis focuses on provision and use of flexibility in the Nordic electricity market. First, this thesis studies wind power variations and accuracy of wind power forecasts in Sweden using statistical methods. Even though today’s wind penetration levels are still low in Sweden, power systems and electricity markets have to cope with these characteristics of variations and forecast errors to a larger extent in future. Second, it investigates to which extent an increased exchange and use of flexibility that is available in the intraday time-frame could efficiently facilitate system balancing and whether this would also be profitable from the power generating companies' perspective. Here, a simulation model is developed that reflects important aspects of production planning and trading decisions in the intraday time-frame. In a first case study, it is shown that the benefits of internal rescheduling strongly depend on the costs to adjust production plans in the intraday time-frame as compared to real-time. In a second case study, it becomes evident that trading flexibility in the intraday time-frame can reduce the need for system balancing more efficiently than internal rescheduling within each balance responsible party. Motivated by the positive gains of intraday trading and the challenge of appropriately modelling continuous intraday markets, trading activity and price development on Elbas is investigated. The results provide insights into trading behaviour on a continuous intraday market and show that trading is not always in accordance to the power system's physical situation. To the extent to which better information and adaptations in the market design could improve the market participants' base for trading decisions, policy recommendations and further research questions areas suggested. / Att använda vindkraft i en större utsträckning är en möjlighet att minska elproduktionens negativa miljöpåverkan. Det finns dock också olika utmaningar med stora mängder vindkraft. Från ett systemperspektiv gäller det till exempel att hålla balansen mellan tillförsel och konsumtion av el. Från elproducenternas perspektiv bör vindkraftens påverkan på elmarknaden nämnas eftersom det påverka aktörernas vinster. Avhandlingen titta närmare in i hur man kan få tillgång till mer flexibilitet på produktionssidan. Avhandlingen består av tre delar. För det första undersöks variationer och prognosfel av vindkraft i Sverige med hjälp av statistiska metoder. Även om andel vindkraft hittills är låg i Sverige, behöver elsystemet och elmarknader i framtiden hantera samma egenskaper av själva variationer och prognosfel som idag men i en större utsträckning. För det andra undersöks hur den flexibiliteten som finns i tidshorisonten några timmar innan leveranstimmen kan utnyttjas för att integrera vindkraften på ett sätt som är både fördelaktigt från systemets och från aktörernas perspektiv. Undersökningen sker med hjälp av en simuleringsmodell som omfattar viktiga delar i produktionsplanering och intradayhandel. I en fallstudie uppvisas att vinster av intern omplanering är i högsta grad beroende på kostnadsskillnaden mellan omplanering några timmar innan leveranstimmen och anpassning av körscheman under själva leveranstimmen. Resultat av ytterligare en fallstudie uppvisar att det är betydligt billigare och mer effektivt att använda intradayhandel istället för intern omplanering för att utnyttja den befintliga flexibiliteten och för att reducera obalanser som systemoperatörer annars behöver ta hand om under leveranstimmen. Detta är en anledning till att undersöka handelsmönster på Elbas som är en intradaymarknad med kontinuerlig handel. En annan anledning till den här tredje delen är utmaningarna i att modellera kontinuerlig intradayhandel. Studien beskriver handelsaktiviteten på Elbas och hur priserna utvecklas under handelstiden. Ett resultat är att handeln inte alltid återspeglar den fysiska situationen i elsystemet. I den utsträckningen som ett snabbare informationsflöde och förändringar i marknadsdesignen kunde förbättrar aktörernas underlag för intradayhandel, föreslås förbättringar och öppna forskningsfrågor. / <p>QC 20150911</p> / Elektra 36141: Korttidsplanering av vatten-värmekraftsystem vid stora mängder vindkraft: System-perspektivet

Author: Martin Karlsson &amp; Sebastian Dahlén, students at Karlstad Business School. Keywords: Bank, repo rate, changes, variable mortgage rate, margins, relationship, competition. Problem formulation: How do banks differ in behavior for increases and decreases of the repo rate. Purpose: The paper aims to examine how banks differ in their response to a decrease and increase in the repo rate. Two periods between 2002-2006 and 2010-2014 were studied to compare the competition on the bank market historically. Background: This segment gives a basic understanding on the bank market, interest rates and loans. Method: The study is a quantitative study of data for the floating mortgage rate over two time periods using regressions models. Articles, literature and reports form the basis of the theory segment. Theory: The paper gives a theoretical understanding on how pricing works on the banking market focusing on oligopoly theory. Empirical data: The data sample is based on secondary data retrieved from the banks’ official web sites. Analysis: The results are analyzed in a separate segment to give a better overview. iv Conclusion: The results show a correlation between the banks mortgage rate and the repo rate. The banks responses to decrease and increases of the repo rate differed for the years 2002-2006 and 2010-2014. For the first period banks were keener on decreasing their mortgage rates than increasing. The opposite relationship was found in the second period.

Learning and memory impairments are among the most common and enduring cognitive consequences of traumatic brain injury (TBI). Researchers have yet to reach a consensus with regard to the basic cognitive mechanism underlying new learning and memory disturbances after TBI. The purpose of the present study was to investigate the current views regarding the cognitive processes thought to explain impairments in verbal learning and memory subsequent to brain injury. Specifically, this study sought to examine the roles of the central executive component of working memory and processing speed in verbal learning ability following TBI. Latent variable structural equation modeling (SEM) was used to analyze the data of 70 post-acute care TBI patients between the ages of 16 and 65, who completed a full neuropsychological evaluation. Results indicated that verbal learning and memory difficulties following TBI were explained primarily in terms of the central executive aspects of working memory, after accounting for the relative contributions of processing speed in the model. The direct effect of processing speed on verbal learning and memory was not significant when working memory was taken into account in the model. Rather, the effects of processing speed on verbal learning ability were largely indirect through the central executive component of working memory. Results highlight the importance of both working memory and processing speed in supporting verbal learning and memory processes after TBI. Practical implications for targeting remediation efforts and directing approaches to memory rehabilitation are discussed in light of the study’s findings. / text

Αντικείμενο αυτής της διπλωματικής εργασίας είναι η μελέτη και προσομοίωση της λειτουργίας μιας ανεμογεννήτριας μεταβλητών στροφών, η οποία οδηγεί μια ασύγχρονη γεννήτρια διπλής τροφοδότησης, με τη βοήθεια του προγράμματος PSCAD/EMTDC. Γίνεται επίσης μελέτη της λειτουργίας αυτής της ανεμογεννήτριας κατά τη διάρκεια βυθίσεων της τάσης του δικτύου, καθώς και μελέτη της δυνατότητας παραμονής της μηχανής σε λειτουργία κατά τη διάρκεια αυτών των σφαλμάτων. Πιο αναλυτικά, στο πρώτο κεφάλαιο γίνεται αναφορά στις ανανεώσιμες πηγές ενέργειας και ειδικότερα στην αιολική ενέργεια και στο σημαντικό ποσοστό ηλεκτρικής ενέργειας, που καλούνται να συνεισφέρουν στο σύνολο του ενεργειακού μείγματος κάθε χώρας, στο μέλλον. Γίνεται αναφορά στο κόστος παραγωγής ηλεκτρικής ενέργειας με χρήση αιολικής ενέργειας και στη συνέχεια το κόστος αυτό συγκρίνεται με το κόστος της ηλεκτρικής ενέργειας που παράγεται από συμβατικούς σταθμούς. Στο δεύτερο κεφάλαιο γίνεται μία γενική παρουσίαση των αιολικών συστημάτων. Περιγράφονται τα δομικά στοιχεία μιας ανεμογεννήτριας και η αεροδυναμική μετατροπή της κινητικής ενέργειας του ανέμου σε ηλεκτρική. Παρουσιάζονται διάφορες τοπολογίες ανεμογεννητριών που χρησιμοποιούνται σήμερα και στη συνέχεια δίνεται το μαθηματικό μοντέλο της γεννήτριας επαγωγής διπλής τροφοδότησης και οι μετασχηματισμοί σε στρεφόμενα πλαίσια αναφοράς. Κατόπιν γίνεται μελέτη του μετατροπέα πηγής τάσης και αναφέρονται τεχνικές διαμόρφωσης για την παραγωγή των επιθυμητών κυματομορφών. Τέλος, γίνεται σχεδιασμός ενός LCL φίλτρου καταστολής των αρμονικών συνιστωσών των ρευμάτων που εγχύει ο μετατροπέας στο δίκτυο. Στο τρίτο κεφάλαιο περιγράφεται ο διανυσματικός έλεγχος και γίνεται εφαρμογή του στον έλεγχο του μετατροπέα προς την πλευρά του δρομέα και στον έλεγχο του μετατροπέα προς την πλευρά του δικτύου. Παρουσιάζεται η γενική στρατηγική ελέγχου της ανεμογεννήτριας με χρήση του ελέγχου βήματος πτερυγίου για τον περιορισμό της παραγώμενης ισχύος στις υψηλές ταχύτητες ανέμου. Όταν η ταχύτητα του ανέμου είναι μικρότερη της ονομαστικής, τότε η ταχύτητα της μηχανής και η παραγώμενη ισχύς ακολουθούν την χαρακτηριστική ισχύος – ταχύτητας, που εξασφαλίζει βέλτιστη λειτουργία. Γίνεται προσομοίωση της λειτουργίας της ανεμογεννήτριας και εκτίμηση της απόκρισης σε βηματικές αλλαγές της ταχύτητας του ανέμου. Στο τέταρτο κεφάλαιο γίνεται μελέτη παραμονής της ανεμογεννήτριας σε λειτουργία, κατά τη διάρκεια βύθισης της τάσης του δικτύου και ανάλυση μεθόδων υλοποίησης αυτού του στόχου. Με την ανίχνευση του σφάλματος ο δρομέας βραχυκυκλώνεται και ο μετατροπέας προς την πλευρά του δρομέα αποσυνδέεται, ενώ οι διακόπτες του αποκόπτονται για να προστατευθούν από το υψηλό ρεύμα του δρομέα. Μόλις το ρεύμα του δρομέα πέσει και πάλι κάτω από την ανώτατη επιτρεπτή τιμή, ο μετατροπέας συνδέεται και πάλι με τον δρομέα για να ανακτήσει τον έλεγχο της παραγώμενης από τον στάτη ενεργού και αέργου ισχύος. Αμέσως παράγεται άεργος ισχύς για την στήριξη της τάσης του δικτύου, ενώ μειώνεται η παραγωγή ενεργού ισχύος, έτσι ώστε το συνολικό ρεύμα του δρομέα να παραμείνει μέσα στα επιτρεπτά όρια. Με την αποκατάσταση της τάσης του δικτύου, η παραγώμενη ενεργός και άεργος ισχύς παίρνουν σταδιακά τις τιμές που είχαν πριν την εκδήλωση του σφάλματος. / -

We first studied factors associated with the rate of colonoscopy by primary care physicians (PCPs) in Ontario between the years 1996 and 2005. Next, we conducted an Instrumental Variable Analysis (IVA) to estimate the effect of colonoscopy on colorectal cancer (CRC) incidence and mortality on average-risk subjects aged 50-74 years. Finally, we explored two study cohorts, one by including subjects who had the outcomes during the exposure period (unselected cohort) and the other cohort by excluding those subjects (restricted cohort). We estimated the absolute risk reduction associated with colonoscopy in preventing CRC incidence and mortality using traditional regression analysis, propensity score analysis and IVA. PCPs who were Canadian medical graduates and with more years of experience were more likely to use colonoscopy. PCPs were more likely to use colonoscopy if their patient populations were predominantly women, older, had more illnesses, and if their patients resided in less marginalized neighborhoods (lower unemployment, fewer immigrants, higher income, higher education, and higher English/French fluency). Using PCP rate of discretionary colonoscopy as an instrumental variable, receipt of colonoscopy was associated with a 0.60% absolute reduction in 7-year CRC incidence and a 0.17% absolute reduction in 5-year risk of death due to CRC. The unselected cohort showed an increase in CRC incidence and mortality associated with colonoscopy, whereas the restricted cohort showed a reduction in CRC incidence and mortality associated with colonoscopy. In the restricted cohort, using different statistical models, the absolute risk reduction varied from 0.52-0.60% for CRC incidence and 0.08-0.17% for CRC mortality. There were social disparities in the use of colonoscopy by PCPs and this disparity increased as the overall use of colonoscopy increased over time. Colonoscopy is effective in reducing incidence and mortality due to CRC. Different methods of subject selection and statistical analysis provided different estimates of colonoscopy effectiveness.

L'objectif de la présente thèse est d'expliquer le passage de novice à expert en matière d'action motrice. L'expert et le novice basent tous deux leurs actions sur une structure « cognitive ». Dans mon modèle de l'action motrice, la structure « cognitive » de l'expert et la structure « cognitive » du novice partagent les mêmes éléments. Ces éléments sont 1) des perceptions de variables optiques de contrôle, 2) des perceptions d'affordances, 3) des intentions (un plan) et 4) un contrôleur moteur. Dans la première partie de ma thèse, je m'applique à définir ces quatre éléments. Lorsque l'agent passe de novice à expert, ces éléments subissent des changements, et la présente thèse a tenté de défendre ces changements. Ces changements ont pour conditions de possibilité des processus d'apprentissage. Donc, pour défendre ces changements, j'ai tenté, dans la seconde partie de ma thèse, de trouver les processus d'apprentissage qui sont à leur origine. Le premier changement dont il a été question est un changement moteur. Lorsque l'agent est novice, les commandes motrices du contrôleur moteur sont inappropriées, tandis que lorsqu'il est expert, ces commandes motrices sont appropriées. Le mécanisme d'apprentissage dont je me suis servi pour expliquer ce changement a été inspiré par le texte de Ashby, Design for a Brain. Le deuxième changement dont il a été question est un changement perceptuel. Lorsqu'il est novice, l'agent ne perçoit pas les bonnes affordances et les bonnes variables optiques de contrôle, tandis que, une fois expert, il les perçoit. Pour rendre compte de ce changement, je me suis inspiré de l'apprentissage par renforcement tel qu'il a été défini par Sutton et Barto (1998). Le troisième et dernier changement dont il a été question consiste en une diminution du plan. Lors de la diminution du plan, l'agent devient de plus en plus réactif. Ce changement est rendu possible par une « fusion » des politiques perceptuelles. Et, pour être optimale, la « fusion » des politiques perceptuelles doit reposer sur un apprentissage par renforcement, le même que celui qui est à l'origine de notre capacité à percevoir les bonnes affordances et les bonnes variables optiques de contrôle. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Affordance, plan, réactivité, variable optique de contrôle, contrôleur moteur.

We first studied factors associated with the rate of colonoscopy by primary care physicians (PCPs) in Ontario between the years 1996 and 2005. Next, we conducted an Instrumental Variable Analysis (IVA) to estimate the effect of colonoscopy on colorectal cancer (CRC) incidence and mortality on average-risk subjects aged 50-74 years. Finally, we explored two study cohorts, one by including subjects who had the outcomes during the exposure period (unselected cohort) and the other cohort by excluding those subjects (restricted cohort). We estimated the absolute risk reduction associated with colonoscopy in preventing CRC incidence and mortality using traditional regression analysis, propensity score analysis and IVA. PCPs who were Canadian medical graduates and with more years of experience were more likely to use colonoscopy. PCPs were more likely to use colonoscopy if their patient populations were predominantly women, older, had more illnesses, and if their patients resided in less marginalized neighborhoods (lower unemployment, fewer immigrants, higher income, higher education, and higher English/French fluency). Using PCP rate of discretionary colonoscopy as an instrumental variable, receipt of colonoscopy was associated with a 0.60% absolute reduction in 7-year CRC incidence and a 0.17% absolute reduction in 5-year risk of death due to CRC. The unselected cohort showed an increase in CRC incidence and mortality associated with colonoscopy, whereas the restricted cohort showed a reduction in CRC incidence and mortality associated with colonoscopy. In the restricted cohort, using different statistical models, the absolute risk reduction varied from 0.52-0.60% for CRC incidence and 0.08-0.17% for CRC mortality. There were social disparities in the use of colonoscopy by PCPs and this disparity increased as the overall use of colonoscopy increased over time. Colonoscopy is effective in reducing incidence and mortality due to CRC. Different methods of subject selection and statistical analysis provided different estimates of colonoscopy effectiveness.

Šiame darbe nagrinėjama atsitiktinio dėmenų (atsitiktinių dydžių) skaičiaus skirstinio funkcijos aproksimacijos normaliuoju dėsniu tolygusis ir netolygusis įverčiai. Atsitiktinių dydžių atsitiktinio dėmenų skaičiaus suma traktuojama kaip draudėjo suminės išmokos. Pilnai išnagrinėtas atvejis, kai atsitiktinis dėmenų skaičius yra homogeninis Puasono procesas. Kita darbo dalis skirta atvejui, kai nėra Puasono procesas. Darbą sudaro 8 dalys: įvadas, analitinė – metodinė dalis, rezultatai, kuriais remsimės darbe, darbo tikslas, darbo rezultatai, publikuotas straipsnis, išvados, literatūros sąrašas. Darbo apimtis – 49 p. teksto be priedų, 2 iliustr., 4 bibliografiniai šaltiniai. / This work analyses the even and not even evaluations of distribution function approximation of random amount of random variables using normal law. The sum of random amount of random variables is treated as assurers total payout. In this paper there is fully explored the case when (random amount of random values) is homogeneous Poisson process. The other part of this work explores the case when is not a Poisson process. Structure: introduction, analytical – methodical part, results, are used in work, woprk point, work results, conclusions, references. Thesis consist of: 49 p. text without appendixes, 2 pictures, 4 bibliographical entries.

The analysis of the feature and application of linear induction motors at work have been performed; mathematical models of linear motors have been studied; mathematical description of induction machine have been presented; coordinate transform have been studied; dynamic equations in moving and move-less systems of axes of linear induction motor have been presented; the analysis of the classification of induction drives control modes have been performed. Four models of the frequency-regulated electric drives with linear induction motors have been studied: when the motor is supplied from variable frequency mains supply, when the motor is supplied from frequency converter, when frequency is changed by program, when frequency is changed in close-loop by vector control system. The characteristics of those models have been compared and performed. The received results are summarized in the conclusions.