The Mīqāt of al-Juhfa is located in the west of Saudi Arabia about 187 km northwest of the Holy City of Mecca. Al-Juhfa is one of the five fixed places called Mawāqīt, or entry stations to the pilgrimage (Hajj). These Mawāqīt were designated during the early Islamic period for any pilgrim comes through them with the intention of Hajj. During the early Abbasid period, al-Juhfa was the largest occupied Mīqāt in the Islamic world. This study focuses primarily on historical and archaeological aspects of the Mīqāt of al-Juhfa during the early Islamic period. To illustrate these aspects, the study analyzed many primary sources that mention al-Juhfa in order to reconstruct the historical and cultural development of the site and to establish the extent to which it functions as an urban center. The study benefited from important information provided by these sources in this respect, such as the chronology of the site, its strategic location, topographical features, the nature of the landscape at different times, the function of specific objects, human activities that took place at the site, and factors that led to its prosperity and decline. The study also undertook a fieldwork at al-Juhfa site—primarily archaeological survey and excavation. This fieldwork enabled us to test the results of the textual analysis and to reveal other characteristics of the site (such as its cultural role, urban elements, planning and defences, architectural functions, building technique, building material, and other features). Moreover, the study analyzed both the formal and technical qualities of all archaeological discoveries on the site, comparing them with their analogues at other early Islamic sites in the Middle East. The study derived many results that clearly indicate the great importance of al-Juhfa as an urban center characterized by several urban functions during the early Abbasid period in the late of 8th century until its importance began to decline gradually between the second half of 11th century and the first half of 12th century. This chronology is supported by both written sources and the archaeological evidence. Several architectural elements and a collection of archaeological finds of different pieces of pottery, ceramic, glass, worked stone, and metal were discovered at al-Juhfa. These discoveries provide us with more information about the extent of mutual influence and active interaction between various cultures during pre-Islamic period as well as the high cultural and commercial level achieved by al-Juhfa and the relationship it had with other Islamic sites in the Middle East. / Graduate / 2019-06-26

Restlöcher ausgekohlter Braunkohlentagebaue werden aus landeskulturellen und ökonomischen Gründen wasserwirtschaftlich als Speicher, Hochwasserrückhaltebecken, Klärteiche, Wassergewinnungsanlagen sowie zur Naherholung genutzt. Diese Restlöcher werden zum großen Teil von aus geschüttetem Abraum bestehenden Böschungen umschlossen. Bei Wasserspiegelschwankungen neigen diese unbefestigten Böschungen zum Rutschen. Als Folge dieser Böschungsrutschungen bilden sich auf der Wasseroberfläche Wellen, die eine beachtliche Größe erreichen können. Diese Schwallwellen übertreffen in ihren Ausmaßen die Windwellen in den Tagebaurestlöchern um ein Vielfaches. Um diese Erscheinungen vorausberechnen zu können, wurden im Hubert-Engels-Laboratorium der Sektion Wasserwesen Untersuchungen durchgeführt. Die Entwicklung einer allgemeingültigen Berechnungsmethode für die Schwallwelle bei der Bewegung eines Teiles der das Wasserbecken begrenzenden Böschung verlangt die Einführung erfassbarer Parameter wie der Breite der rutschenden Böschung, den zeitlichen Verlauf der Wasserverdrängung sowie Tiefen- und Lageverhältnisse des Beckens. Die dafür notwendigen Kennzahlen können nur näherungsweise bestimmt werden, so dass einfache Beckengeometrien, ein über die Rutschzeit gleich bleibender Verlauf der Wasserverdrängung und Erhaltung der Böschungskante einem Berechnungsverfahren zugrunde gelegt werden müssen. Für die Berechnung des Füllschwalles auf das ruhende Wasser sind einige Verfahren bekannt geworden, die auf eine gemeinsame Gleichung für die Berechnung der Schwallhöhe zurückzuführen sind. Für die ebene Ausbreitung des Füllschwalles über Ruhewasser ergeben sieh zwei prinzipielle Abflussmöglichkeiten: Auflösung in Wellen oder brandender Schwallkopf. Diese beiden Möglichkeiten sowie der Übergangsbereich werden durch FROUDE-zahlen festgelegt. Der Wellenkopf von Füllschwallwellen wird durch eine Einzelwelle gebildet. Die Rutschung einer Böschung wurde durch die gleichzeitige Horizontal- und Vertikalbewegung einer Platte nachgebildet. Die Bewegung der Platte, die entstehenden Wellen und die Kräfte auf Auflaufböschung wurden durch einen Oszillografen aufgezeichnet. Die Auswertung der Versuche ergab eine Übereinstimmung zwischen Messergebnissen und den Berechnungen nach den Gesetzen des Füllschwalls. Die sekundlich verdrängte Wassermenge pro Breiteneinheit und die Ruhewassertiefe bestimmen die entstehenden Schwallwellen. Ein Einfluss der vertikalen Bewegungskomponente ist im untersuchten Bereich nicht nachweisbar. Die dynamischen Kräfte auf die Abschlussböschung können durch den Impuls der Einzelwelle dargestellt werden. Die räumliche Ausbreitung der Schwallwellen wurde in einem Modell untersucht. Dabei wurde festgestellt, dass die größten Wellenhöhen in der Richtung der Bewegung der Platte auftreten, während die Wellenhöhen in seitlichen Ausbreitungsrichtungen kleiner sind. Berechnungsansätze für die maximale Wellenhöhe der front wurden ermittelt. Als Ergebnis wurde ein Berechnungsverfahren entwickelt, welches ausgehend von den Parametern dar Rutschung, die Eigenschaften der Schwallwellen einschließlich der durch sie hervorgerufenen Belastungen auf der Auflaufböschung ermöglicht. Mit diesem Berechnungsverfahren ist es möglich, Böschungen wirtschaftlich zu gestalten und schädliche Rückwirkungen auf das Staubecken durch Schwallwellen zu vermeiden. Bisher notwendige Kosten für eine sehr flache Gestaltung der Böschung können entfallen. Gleichzeitig bleibt ein größerer nutzbarer Stauraum erhalten. Die Digitalisierung der vorliegenden Arbeit durch die Sächsische Landesbibliothek - Staats- und Universitätsbibliothek Dresden (SLUB) wurde durch die Gesellschaft der Förderer des Hubert-Engels-Institutes für Wasserbau und Technische Hydromechanik an der Technischen Universität Dresden e.V. unterstützt.

Den tekniska utvecklingen har varit storskalig i världen och människors vardagsliv harändrats mycket det senaste seklet. I kontrast till detta har den svenska skolan inte sett sammahastiga tekniska utveckling. Samtidigt visar resultat från PISA att elevers resultat i matematiksjunker. Här identifieras två problem som måste lösas. Därför syftade denna undersökningtill att underlätta elevers matematikstudier genom att skapa en ny digital lärmiljö. Lärmiljönkom att kombinera matematiska lösningsförslag med nätcoaching. Det gjordes med hjälp avdet digitala läromedlet Mathleaks och lärplattformen TalkMath. Därefter analysera hur entill-en nätcoaching fungerade i denna nya lärmiljö. Undersökningen syftade även ta reda påhur elever uppfattar lärmiljön och om den kan vara ett komplement till lösningsförslag.Lärmiljön skapades med grund i pedagogiska teorier såsom Vygotskijs sociokulturellaperspektiv, teorier om coaching, synkron kommunikation samt teorier om en-till-ennätcoaching. Två metoder användes för att samla denna data. För det första sparades allakonversationer automatiskt i en databas. För det andra så användes en enkät för att samlaelevernas uppfattning av lärmiljön. Ramverket Undersökande relation användes för attanalysera alla konversationerna mellan elev och coach. Studenterna valdes ut från en svenskgymnasieskola där en av författarna jobbar, eleverna var i åldrarna 15-18 år. Resultatenindikerade att denna nya lärmiljö var ett bra komplement till lösningsförslag. Det drogs ävenslutsatsen att lärmiljön hjälpte elevers kognitiva progression. Undersökningen visar att endigital lärmiljö kan vara ett bra komplement för elever som studerar matematik medlösningsförslag. / The digital and technical development of the world have been large-scale and people’s day-to day life has changed immensely the last century. In contrast, the Swedish school system has not been seeing the same rapid technical development. As students’ results in mathematic sare declining an approach to battle this trend can be to apply this technological development on students’ studies in mathematics. Therefore, this thesis sought to ease students’ mathematics studies by creating a digital learning environment. By combining worked examples with online coaching the environment was created through the platforms Mathleaks and TalkMath. Then examine how online one-to-one coaching works in this environment. It also sought to analyse how students perceive this teaching environment and if it can be usedas a complement to worked-examples. The environment was created based on pedagogical theories such as Vygotsky's sociocultural perspective, coach theories, synchronous communication as well as theory around one-to-one online coaching. Two methods were used to gather data. First, the conversations were automatically stored in a database. Secondly, a survey was used to gather the students’ opinion of the teaching environment. The framework Relationship of Inquiry was used to analyse all conversations between students and coaches. Students were chosen from an upper secondary school in the ages of 15-18 where one of the authors worked. Results indicated that the teaching environment that was created was a good complement to worked-examples. The environment was shown to help student’s knowledge progression. This shows that digital teaching environments can be a valuable addition for students when studying mathematics.

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Yes / To reproduce the natural flow topography in a laboratory environment, it is crucial to recapture its bed condition in order to ensure the accurate representation. Water-worked bed represents a state-of-the-art experimentally formed bed to imitate the natural-formed channel in most rivers or natural streams. Recently, this technique has been intensively studied through experimental and computational approaches; however, its actual influence towards the near-bed flow as compared to experimentally prepared rough bed in well-packed bedform order are still yet to be investigated deeply. This experimental study systematically investigated and compared the differences in velocity distribution and three-dimensional (3D) turbulence characteristics, including turbulence intensities and Reynolds stresses, between uniform smooth bed, laboratory-prepared rough bed and water-worked bed open channel flows. The flow comparisons were concentrated at near-bed region where clear flow behaviour change can be observed. Through these comparisons, the study inspected the characteristics of water-worked bedform thoroughly, in order to inform future experimental research that tries to reproduce natural stream behaviours. / the Major State Basic Research Development Grant No. 2013CB036402 from Tsinghua University. The support from the Major State Basic Research Development Program (973 program) of China is also greatly appreciated. We also acknowledge the National Key Research and Development Project from the Ministry of Science and Technology during the Thirteenth Five-year Plan Period (Grant No. 2017YFC0403600) and the Science and Technology Projects State Grid Corporation of China (Grant No. 52283014000T).

A key challenge of the learning sciences is moving research results into practice. Educators on the front lines perceive little value in the outputs of education research and demand more “usable knowledge”. This work explores the potential instead of usable artifacts to translate knowledge into practice, adding scientists as stakeholders in an interaction design process. The contributions are two effective systems, the scientific and contextual principles in their design, and a research model for scientific research through interaction design. College student study practices are the domain chosen for the development of these methods. Iterative ethnographic fieldwork identified two systems that would be likely to advance both learning in practice and knowledge for applying the employed theories in general. Nudge was designed to improve students’ study time management by regularly emailing students with explicit recommended study activities. It reconceptualizes the syllabus into an interactive guide that fits into modern students' attention streams. Examplify was designed to improve how students learn from worked example problems by modularizing them into steps and scaffolding their metacognitive behaviors though problem-solving and self-explanation prompts. It combines these techniques in a way that is exceedingly easy to author, using existing answer keys and students' self-evaluations. Nudge and Examplify were evaluated experimentally over a full semester of a lecture-based introductory chemistry course. Nudge messages increased students’ sense of achievement and interacted with students’ existing time management skills to improve exam grades for poorer students. Among students who could choose whether to receive them, 80% did. Students with access to Examplify had higher exam scores (d=0.26), especially on delayed measures of learning (d=0.40). A key design decision in Examplify was not clearly resolvable by existing theory and so was tested experimentally by comparing two variants, one without prompts to solve the steps. The variant without problem solving was less effective (d=0.77) and less used, while usage rates of the variant with problem solving increased over time. These results support the use of the design methods employed and provide specific empirical recommendations for future designs of these and similar systems for implementing theory in practice.

The aim of the dissertation thesis is to develop a methodology of the compilation of symmetric Time Input-Output tables under the conditions of the Czech Republic. The following aim is to create an input-output model which is based on the compiled symmetric Time Input-Output tables. For the practical applications of this model it is crucial to link the created Input-Output model with the Semi-Dynamic Input-Output model. Semi-Dynamic Input-Output model in the conception of the submitted dissertation thesis takes into account several multiplier effects and presents more comprehensive tool for the use of the Input-Output analyses in this way. The first chapter focuses on the development of the issues linked to the Input-Output tables and analyses on the territory of the Czech Republic and in the world as well. The second chapter which is also theoretical is focused on mapping of different kinds of Input-Output analyses which are done in the world using Physical, Time or Hybrid Input-Output tables. The third chapter is a purely methodological because here it is described the methodology of the compilation of symmetric Time Input-Output tables as well as methodological approach to the various sensitivity analyses. The fourth chapter focuses on the creation Semi-Dynamic Input-Output model and on the formal linking with the Input-Output model based on the Time Input-Output tables. The last fifth chapter is focused analytically. Methods described in the third chapter are applied on the official published data on the Czech economy. The analytical chapter is perceived in the submitted dissertation thesis as a tool for the sensitivity analysis in the sense of validation of the quality of the compiled Time Input-Output tables.

<p>User onboarding for Graphical User Interface (GUI) applications usually involve walkthrough tutorials explaining various UI elements, functions, and navigation screens. These First-time User Experiences (FTUEs) are crucial in determining any subsequent user interaction. The purpose of this study has been explored by eliciting answers to two research questions in specific. The study primarily investigates a user's perception of a tailored onboarding experience. Following this, the impact of these tutorials on the user's performance has also been used as a way to verify their effectiveness.</p> <p><br></p> <p>The emergence of educational crowdsourcing platforms has revolutionized traditional models of teaching and learning by engaging students in collaborative, real-world problem-solving activities. However, the success of crowdsourcing platforms in education largely depends on their ability to provide a positive and engaging user experience, particularly for first-time users. As a part of another ongoing study, the need for an engaging onboarding tutorial to educate users on the concept of worked-out examples and peer evaluations was evident. Thus, the interventions developed in this study are built upon a crowdsourcing platform designed to collect worked-out examples from university students. </p> <p><br></p> <p>Through a combination of qualitative and quantitative research methods, this study seeks to provide insights into the design of effective onboarding tutorials in the context of crowdsourcing educational resources. There have been numerous attempts to devise effective onboarding strategies. For instance, the interplay of narration and animation has been utilized as a way to gamify and design engaging FTUEs. The design choices for tailoring the experience were hence determined through Rapid Iterative Testing and Evaluation (RITE) methods. Analysis of the experimental data shows that there is a statistically significant improvement in the FTUE when users are presented with a tailored onboarding tutorial. Their usage patterns also tend to improve post their interactions with the tutorials. These results hope to contribute to a better understanding of user engagement in FTUEs, thus paving the way for furthering product adoption and value metrics on a broad scale.</p>

The aim of this study was to investigate the comparative effects of Constructivist-Based Teaching Method (CBTM) and the Traditional Teaching Method (TTM) on Grade 11 Mathematics learners’ errors in algebra. The constructivist learning theory (CLT) was used to frame this study. Mainly, CLT was used to influence the design of CBTI to hone participants’ errors in algebra that militate against their performance in Mathematics. The study was conducted in the Mpumalanga Province of South Africa with a four-week intervention programme in each of the two participating secondary schools. Participants consisted of n=78 Grade 11 Mathematics learners and one Grade 11 Mathematics teacher. A non-equivalent control group design consisting of a pre-test and post-test measure was employed. The Grade 11 teacher in the control school employed the TTM while the researcher implemented CBTM in the experimental school. The main aspects of CBTM entailed participants’ construction of their own knowledge from the base of prior knowledge and through group learning approach and exploratory talk in which discussions included argumentation, verbalising explanations, justifications and reflections. Participants in experimental school became familiar with the basic principles of CBTI such as group work, which enhanced the construction of conceptual understanding of algebraic concepts. This reduced most of the errors they commit in algebra and elevated their performance in Mathematics. The principal instruments for data collection consisted of a standardised Algebra Concept Achievement Test and lesson observations. The pre-test was used to determine participants’ initial errors in algebra before the intervention. A post-test was given at the end of intervention to ascertain change in participants’ errors in algebra over a four-week intervention period. Using descriptive and inferential statistical techniques, the study found that participants in experimental school significantly reduced their errors in algebra than those in control school. The study showed that CBTM was a more effective pedagogy that improved the errors Grade 11 learners commit in algebra than the TTM. / College of Education / M. Ed. (Mathematics Education)

The aim of this study was to investigate the effect of context-based problem solving instruction (CBPSI) on the problem solving performance of Grade 10 learners, who performed poorly in mathematics. A cognitive load theory (CLT) was used to frame the study. In addition, CLT was used to: 1) facilitate the interpretation and explanation of participants‟ problem solving performance; and, 2) influence the design of CBPSI to hone participants‟ problem solving skills. The study was conducted in the Gauteng province of South Africa and involved a two-week intervention program in each of the nine participating high schools. Participants consisted of 783 learners and four Grade 10 mathematics teachers. A non-equivalent control group design was employed, consisting of a pre- and post- measure. In addition, classroom observations and semi-structured interviews were conducted with teachers and learners. Teachers employed conventional problem solving instructions in four control schools while the researcher implemented CBPSI in five experimental schools. Instruction in experimental schools entailed several worked-out context-based problem solving examples given to participants in worksheets. The main aspects of CBPSI embraced elements of the effects of self-explanation and split-attention, as advocated by CLT. Due to the design of CBPSI participants in experimental schools became familiar with the basic context-based problem solving tasks that were presented to them through the worked-out example samples. In turn, the associated cognitive load of problem solving tasks was gradually reduced. The principal instrument for data collection was a standardized Functional Mathematics Achievement Test. The pre-test determined participants‟ initial problem solving status before intervention. A post-test was given at the end of intervention to benchmark change in the functionality of CBPSI over a two-week period. Using one-way analysis of covariance (ANCOVA), Analysis of Variance (ANOVA), and other statistical techniques the study found that participants in experimental schools performed significantly better than participants in control schools on certain aspects of problem solving performance. In addition, semi-structured interviews and classroom observations revealed that participants rated CBPSI highly. On the whole, the study showed that CBPSI is an effective instructional tool to enhance the problem solving performance of Grade 10 mathematics learners. / Mathematics Education / D. Phil. (Mathematics, Science and Technology Education)