Humans are in general poor at making judgments that adhere to the logical principles of probability theory. One demonstration of this is termed the “conjunction fallacy”: judging a conjunction (A&B) as being more probable than its constituent (A). Systematic commitment of the conjunction fallacy has been shown in numerous studies on probability judgments. Different actions to remedy the fallacy have been suggested. According to the nested-sets hypothesis, when the nested-set structure of a problem becomes clear (i.e. the relation between categories and subcategories), then the conjunction fallacy is remedied. However, previous demonstrations of this remediation have provided very explicit task-related information and it can be questioned whether it is trivial that such information leads to more correct judgments. The primary aim of this study was to test the nested- sets hypothesis in two different formats of a probability judgment task, by more subtly hinting about the nested-set structure. Twenty-nine participants were randomly divided into two groups, one Probability condition and one Informed probability condition, where participants in the latter condition were provided with the hint. The second aim was to investigate whether the Informed probability condition was performed more slowly, potentially due to the time-cost of more elaborated judgments. The results show that a subtle hint about the nested-set structure was able to remedy the conjunction fallacy in a forced-choice probability judgment task but not statistically reliably in a probability estimation task. No response-time differences were observed between the conditions. The results support the nested-sets hypothesis and imply that even a subtle reasoning hint clarifying the relation between categories and subcategories might remedy one of the most robust probability judgment fallacies. / Människor är i allmänhet dåliga på att göra bedömningar som följer principer för sannolikhetsteori. En indikation på det är ”konjunktionsfelet”: att bedöma en konjunktion (A&B) som mer sannolik än sin konstituent (A). Konjunktionsfelet har påvisats i flera studier på sannolikhetsbedömningar. Olika sätt att avhjälpa felet har föreslagits. Enligt nested-set hypotesen föreslås att när nested-set strukturen av ett problem blir tydlig (dvs. relationen mellan kategorier och subkategorier), minskas benägenheten att begå konjunktionsfelet. Däremot har tidigare demonstrationer av den här minskningen angett väldigt explicit uppgifts-relaterad information och det kan ifrågasättas om det är trivialt att sådan information leder till mer korrekta bedömningar. Studiens primära syfte var att testa nested-set hypotesen i två olika sannolikhetsbedömningsformat, genom att subtilt antyda om nested-set strukturen. Tjugonio deltagare delades slumpmässigt in i två grupper, en Sannolikhetsbetingelse och en Informerad sannolikhetsbetingelse, där den senare betingelsen fick den extra informationen. Det andra syftet var att undersöka om Informerad sannolikhetsbetingelsen skulle utföras långsammare, potentiellt på grund av tids-kostnaden av mer elaborerade bedömningar. Resultatet visar att en subtil antydan om nested-set strukturen minskade konjunktionsfelet i en fler-vals uppgift på sannolikhetsbedömningar men inte statistiskt pålitligt i en sannolikhetsestimeringsuppgift. Inga responstidsskillnader hittades mellan betingelserna. Resultat stödjer nested-set hypotesen och antyder att även en subtil antydan som klargör relationen mellan kategorier och underkategorier kan åtgärda ett av de mest robusta tankefel som observerats vid sannolikhetsbedömningar.

Dynamic memory allocators are a determining factor of an application's performanceand have the opportunity to improve a major performance bottleneck ontoday's computer hardware: data locality. To approach this problem, a memoryallocator must rst oer strategies that allow the locality problem to be addressed.However, while focusing on locality, an allocator must also not ignore the existing constraintsof allocation speed and fragmentation, which further complicate its design. Inorder for a locality improving technique to be successfully employed in today's largecode applications, its integration needs to be automatic, without user intervention.The alternative, manual integration, is not a tractable solution.In this dissertation we develop three novel memory allocators that explore dierentallocation strategies that enhance an application's locality. We conduct the rststudy that shows that allocation speed, fragmentation and locality improving goalsare antagonistic. We develop an automatic method that supplies allocation hintsfrom C++ STL containers to their allocators. This method allows applications tobenet from locality improving techniques at the cost of a simple re-compilation. Weconduct the rst study that quanties the eect of allocation hints on performance,and show that an allocator with high locality of reference can be as competitive asone using an application's spatial feedback.To further allow dynamic memory allocation to improve an application's performance,new and non-traditional strategies need be explored. We develop a generic software tool that allows users to examine unconventional strategies. The tool allowsusers not only to focus on allocation strategies rather than their implementation, butalso to compare and contrast various approaches.

Dynamic memory allocators are a determining factor of an application's performanceand have the opportunity to improve a major performance bottleneck ontoday's computer hardware: data locality. To approach this problem, a memoryallocator must rst oer strategies that allow the locality problem to be addressed.However, while focusing on locality, an allocator must also not ignore the existing constraintsof allocation speed and fragmentation, which further complicate its design. Inorder for a locality improving technique to be successfully employed in today's largecode applications, its integration needs to be automatic, without user intervention.The alternative, manual integration, is not a tractable solution.In this dissertation we develop three novel memory allocators that explore dierentallocation strategies that enhance an application's locality. We conduct the rststudy that shows that allocation speed, fragmentation and locality improving goalsare antagonistic. We develop an automatic method that supplies allocation hintsfrom C++ STL containers to their allocators. This method allows applications tobenet from locality improving techniques at the cost of a simple re-compilation. Weconduct the rst study that quanties the eect of allocation hints on performance,and show that an allocator with high locality of reference can be as competitive asone using an application's spatial feedback.To further allow dynamic memory allocation to improve an application's performance,new and non-traditional strategies need be explored. We develop a generic software tool that allows users to examine unconventional strategies. The tool allowsusers not only to focus on allocation strategies rather than their implementation, butalso to compare and contrast various approaches.

Feedback is an essential component of the learning process, but in fields like computer science, which have rapidly increasing class sizes, it can be difficult to provide feedback to students at scale. Intelligent tutoring systems can provide personalized feedback to students automatically, but they can take large amounts of time and expert knowledge to build, especially when determining how to give students hints. Data-driven approaches can be used to provide personalized next-step hints automatically and at scale, by mining previous students’ solutions. I have created ITAP, the Intelligent Teaching Assistant for Programming, which automatically generates next-step hints for students in basic Python programming assignments. ITAP is composed of three stages: canonicalization, where a student's code is transformed to an abstracted representation; path construction, where the closest correct state is identified and a series of edits to that goal state are generated; and reification, where the edits are transformed back into the student's original context. With these techniques, ITAP can generate next-step hints for 100% of student submissions, and can even chain these hints together to generate a worked example. Initial analysis showed that hints could be used in practice problems in a real classroom environment, but also demonstrated that students' relationships with hints and help-seeking were complex and required deeper investigation. In my thesis work, I surveyed and interviewed students about their experience with helpseeking and using feedback, and found that students wanted more detail in hints than was initially provided. To determine how hints should be structured, I ran a usability study with programmers at varying levels of knowledge, where I found that more novice students needed much higher levels of content and detail in hints than was traditionally given. I also found that examples were commonly used in the learning process, and could serve an integral role in the feedback provision process. I then ran a randomized control trial experiment to determine the effect of next-step hints on learning and time-on-task in a practice session, and found that having hints available resulted in students spending 13.7% less time during practice while achieving the same learning results as the control group. Finally, I used the data collected during these experiments to measure ITAP’s performance over time, and found that generated hints improved as data was added to the system. My dissertation has contributed to the fields of computer science education, learning science, human-computer interaction, and data-driven tutoring. In computer science education, I have created ITAP, which can serve as a practice resource for future programming students during learning. In the learning sciences, I have replicated the expertise reversal effect by finding that more expert programmers want less detail in hints than novice programmers; this finding is important as it implies that programming teachers may provide novices with less assistance than they need. I have contributed to the literature on human-computer interaction by identifying multiple possible representations of hint messages, and analyzing how users react to and learn from these different formats during program debugging. Finally, I have contributed to the new field of data-driven tutoring by establishing that it is possible to always provide students with next-step hints, even without a starting dataset beyond the instructor’s solution, and by demonstrating that those hints can be improved automatically over time.

Understanding speech in background noise is occasionally difficult for normal hearing listeners and is often impossible for the listener with sensorineural hearing loss. The ability to understand speech in noise depends upon multiple factors such as the characteristics of the speech signal, the signal-to-noise ratio, and the listener's degree of hearing impairment. A routine hearing evaluation usually does not provide ample information about a listener's functional communication abilities. The Hearing-in-Noise Test (HINT) developed by The House Ear Institute provides an efficient and reliable method for evaluating an individual's suprathreshold speech understanding ability in quiet and in noise. The purpose of this pilot study was to investigate monaural speech reception thresholds for sentences (RTS) in quiet and in noise using the standardized Hearing-in-Noise Test (HINT). Data was collected from one clinical setting using twenty-five subjects with bilateral normal hearing (WNL) and twenty subjects with bilaterally symmetrical sensorineural hearing loss (SNHL). Subject age ranged from 40 to 65 years. The study results were generally in agreement with the HINT norms. It was concluded that administering the HINT monaurally under headphones could differentiate between normal hearing individuals and individuals with cochlear hearing loss. The SNHL group exhibited higher RTSs than the WNL group in both quiet and in noise. The mean RTS difference between the two groups in quiet was 14.56 dB while the mean RTS difference in noise was only 2.85 dB. Surprisingly, the difference between the two subject groups in quiet was greater than was expected.

La signalisation calcique joue un rôle crucial dans la réponse des cellules aux signaux extracellulaires. Ces dernières années, les progrès des techniques de microscopie ont permis de montrer que l’organisation spatio-temporelle du signal calcique était un élément fondamental de la réponse des cellules. L'organisation temporelle du signal calcium se caractérise ainsi par l'observation d'oscillations de calcium dont la fréquence varie en fonction du stimulus. Pour de nombreux types cellulaires, et notamment pour les hépatocytes, modèle cellulaire de notre étude, l’amplitude et la fréquence des oscillations de calcium sont très régulières et finement régulées. Les nombreux facteurs qui interviennent pour assurer cette régulation rendent l'étude de ce processus difficile. Ceci explique que l’étude des oscillations de calcium est un des domaines dans lequel l’aspect expérimental est communément complété avec la modélisation mathématique.Parmi les nombreux éléments qui participent à la régulation du signal calcique, les mitochondries qui ont longtemps été considérées comme ayant un rôle passif, pourraient jouer un rôle important. En effet il a été établi que les mitochondries étaient capables d’accumuler de façon active le calcium libéré par le reticulum endoplasmique. Notre objectif a donc été d’étudier l’importance des mitochondries dans la régulation des oscillations de calcium dans les hépatocytes, et grâce à nos résultats expérimentaux, de mettre au point un modèle mathématique. Pour cela nous avons choisi de modifier la prise de calcium par les mitochondries en altérant le moins possible leur fonctionnement normal. Nous avons utilisé une protéine altérant directement la prise de calcium par les mitochondries (HINT 2) et une autre protéine altérant l’interaction entre le reticulum endoplasmique et les mitochondries (R-1). Nos résultats expérimentaux et computationnels démontrent que la protéine HINT 2 augmente l’activité de la chaine respiratoire, ce qui a pour effet d’accélérer l’accumulation de calcium par les mitochondries et d’augmenter la fréquence des oscillations de calcium cytosolique dans les hépatocytes. En effet le modèle élaboré permet à la fois de reproduire les observations expérimentales mais également de prédire avec succès que l’absence de la protéine Hint 2 rend les mitochondries plus sensibles à l’ouverture du pore de transition mitochondrial (mPTP). Nous avons également démontré que le R-1 n’affecte pas significativement la prise de calcium par les mitochondries mais que sa surexpression aboutit à une élévation de la concentration calcique de base des cellules hépatocytaires. A la lumière de nos résultats, cette élévation de la concentration de calcium basale semble être due à son interaction physique avec la pompe ATPase SERCA 2. Nos résultats nous ont permis de mettre en évidence à la fois la contribution des mitochondries dans la régulation des oscillations de calcium dans les hépatocytes grâce à la protéine Hint 2, mais aussi le lien direct entre la surexpression du R-1 et l’élévation de la concentration en calcium de base dans les cellules HepG2. / Calcium signaling plays a crucial role in cell response to external stimuli. These last years, the progress of the microsocopy techniques allowed demonstrate that spatio-temporal organisation of the calcium signal is fundamental for cell physiology. This spatio-temporal organization is characterized by the observation of calcium oscillations whose frequency varies according to the stimulus. For many cell types in particular hepatocytes, calcium oscillations amplitude and frequency are regular and finely regulated. The large range of actors involved in this regulation explains the complexity of studying this process. This explains why the calcium oscillations studies are one of the area in which the experimental approach is commonly associated with computational approaches.Among all the elements participating in the regulation of calcium signaling, mitochondria that have been thought for many years to play a passive role may have a greater role. Indeed it has been shown that mitochondria are able to accumulate actively calcium from the endoplasmic reticulum.Our goal was to study the importance of mitochondria in calcium oscillations regulation in hepatocytes and to elaborate a model based on these experimental results. For that purpose we choose to change the calcium uptake by mitochondria using techniques that didn’t kill them. We used a protein that alters directly mitochondrial calcium uptake (Hint 2), and a protein involved in the interaction between endoplasmic reticulum and mitochondria (R-1).Our experimental and computational results show that HINT 2 enhances the electron transport chain activity, which lead to faster mitochondrial calcium uptake and faster calcium oscillations in the cytosol of hepatocytes. The model allows us not only to reproduce experimental data but also to successfully predict that the loss of HINT 2 lead the mitochondria to be more sensitive to the mitochondrial transition pore opening (mPTP).We also demonstrate that R-1 doesn’t change mitochondrial calcium uptake, but its over expression lead to a higher calcium concentration in resting cells. In the light of our results, this higher calcium concentration seems to be the result of R-1 interaction with ATPase pump SERCA 2.Our results allowed us to show not only the role of mitochondria in the regulation of hepatocytes calcium oscillations by HINT 2, but also the link between R-1 over expression and a higher calcium concentration in the cytosol of HepG2 cells.

The overall aim of the research is to develop a computational platform based on HINT paradigm for manipulating, predicting and analyzing biomacromolecular-ligand structure. A second synergistic goal is to apply the above methodology to design novel and potent anti-cancer agents. The crucial role of the microtubule in cell division has identified tubulin as an interesting target for the development of therapeutics for cancer. Pyrrole-containing molecules derived from nature have proven to be particularly useful as lead compounds for drug development. We have designed and developed a series of substituted pyrroles that inhibit growth and promote death of breast tumor cells at nM and μM concentrations in human breast tumor cell lines. In another project, stilbene analogs were designed and developed as microtubule depolymerizing agents that showed anti-leukemic activity. A molecular modeling study was carried out to accurately represent the complex structure and the binding mode of a new class of tubulin inhibitors that bind at the αβ-tubulin colchicine site. These studies coupled with HINT interaction analyses were able to describe the complex structure and the binding modes of inhibitors. Qualitative analyses of the results showed general agreement with the experimental in vitro biological activity for these derivatives. Consequently, we have been designing new analogs that can be synthesized and tested; we believe that these molecules will be highly selective against cancer cells with minimal toxicity to the host tissue. Another goal of our research is to develop computational tools for drug design. The development and implementation of a novel cavity detection algorithm is also reported and discussed. The algorithm named VICE (Vectorial Identification of Cavity Extents) utilizes HINT toolkit functions to identify and delineate a binding pocket in a protein. The program is based on geometric criteria and applies simple integer grid maps to delineate binding sites. The algorithm was extensively tested on a diverse set of proteins and detects binding pockets of different shapes and sizes. The study also implemented the computational titration algorithm to understand the complexity of ligand binding and protonation state in the active site of HIV-1 protease. The Computational titration algorithm is a powerful tool for understanding ligand binding in a complex biochemical environment and allows generating hypothesis on the best model for binding.

Title: Book of problems of kinematics of mass point Author: Jana Moltašová Department: Department of Physics Education Supervisor: RNDr. Dana Mandíková, CSc. Supervisor's e-mail address: Dana.Mandikova@mff.cuni.cz Abstract: This thesis is a follow-up to the bachelor thesis titled Book of problems of kinematics of mass point for students of Physics Education. This work is a part of wider project which aim is to create an electronic collection of problems completed with detailed solutions and structured hints. Within the frame of this work was made part of collection with forty problems, which theme is kinematics of mass point. Most of problems were chosen from already existing collections and textbooks. Each problem contains task, system of hints and resulting solutions of hints, detailed solution and answer. At the beginning of the work are given aims of the work and its structure. In the next part of work is mentioned a survey of curriculum which is instructed in lower and upper secondary school and university in brief, which relates to this theme. The next part is a survey and brief characterization of collections of problems with this theme. The fourth part of the work is devoted to the electronic collection of problems, its history, the technical elaboration of problems, there is described the...

Professional research project (Au.D.)--University of South Florida, 2003. / Title from PDF of title page. / Document formatted into pages; contains 25 pages. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: Understanding speech in background noise is occasionally difficult for normal hearing listeners and is often impossible for the listener with sensorineural hearing loss. The ability to understand speech in noise depends upon multiple factors such as the characteristics of the speech signal, the signal-to-noise ratio, and the listener's degree of hearing impairment. A routine hearing evaluation usually does not provide ample information about a listener's functional communication abilities. The Hearing-in-Noise Test (HINT) developed by The House Ear Institute provides an efficient and reliable method for evaluating an individual's suprathreshold speech understanding ability in quiet and in noise. / ABSTRACT: The purpose of this pilot study was to investigate monaural speech reception thresholds for sentences (RTS) in quiet and in noise using the standardized Hearing-in-Noise Test (HINT). Data was collected from one clinical setting using twenty-five subjects with bilateral normal hearing (WNL) and twenty subjects with bilaterally symmetrical sensorineural hearing loss (SNHL). Subject age ranged from 40 to 65 years. The study results were generally in agreement with the HINT norms. It was concluded that administering the HINT monaurally under headphones could differentiate between normal hearing individuals and individuals with cochlear hearing loss. The SNHL group exhibited higher RTSs than the WNL group in both quiet and in noise. The mean RTS difference between the two groups in quiet was 14.56 dB while the mean RTS difference in noise was only 2.85 dB. Surprisingly, the difference between the two subject groups in quiet was greater than was expected. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Ett formativt arbetssätt framhålls som produktivt för elevers lärande (Balan, 2012). Samtidigt beskriver Jönsson (2008) att verksamma lärare har svårt att ta sig an arbetssättet då det är omfattande och tidskrävande. Denna motsättning vill vi reflektera kring och närma oss med hjälp av en utarbetad uppgift och hint-kort (ledtrådar) som formativt verktyg för eleverna. Syftet är att undersöka elevers uppfattningar kring användandet av hint-kort och huruvida de upplever att uppgiftens upplägg påverkar deras lärande.Martons variationsteori framhåller kritiska aspekter och kritiska drag som avgörande för att elever skall kunna närma sig ett lärandeobjekt (Marton & Booth, 1997). Vidare ligger denna teori som grund för utformningen av våra hint-kort. Uppgiftens upplägg kopplas till variationsteorin och tidigare forskning som framhåller vikten av förförståelse och metakognition. En kvalitativ metod i form av 10 intervjuer användes för att undersöka elevers uppfattningar kring uppgiftens upplägg och hint-kort. Resultatet analyserades utifrån fenomenografi, en empirisk strävan som grundar sig i att beskriva upplevelser av olika fenomen. Resultatet visar att majoriteten av eleverna ställde sig positiva till hint-korten och uppgiftens upplägg. Ett flertal elever upplevde att hint-korten hjälpte dem att spara tid och därmed effektivisera det egna lärandet. Ytterligare en upplevelse ett flertal elever framhöll var en känsla av trygghet pga. möjligheten att få extra stöd av hint-korten. De elever vars upplevelser av uppgiftens upplägg och hint-korten var mindre positiva saknade förförståelse för lärandeobjektet och ämnesområdet. Dessa elever kunde inte ta sig an uppgiften och dess upplägg med stöd från hint-korten i samma utsträckning som de elever som hade adekvat förförståelse. Detta är i linje med variationsteorin som menar att hur väl man tar sig an ett lärandeobjekt beror på vilka kritiska aspekter man har fått möta tidigare.