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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

Resource-efficient image segmentation using self-supervision and active learning

Max, Muriel January 2021 (has links)
Neural Networks have been demonstrated to perform well in computer vision tasks, especially in the field of semantic segmentation, where a classification is performed on a per pixel-level. Using deep learning can reduce time and effort in comparison to manual segmentation, however, the performance of neural networks highly depends on the data quality and quantity, which is costly and time-consuming to obtain; especially for image segmentation tasks. In this work, this problem is addressed by investigating a combined approach of self-supervised pre-training and active learning aimed at selecting the most informative training samples. Experiments were performed using the Gland Segmentation and BraTS 2020 datasets. The results indicate that active learning can increase performance for both datasets when only a small percentage of labeled data is used. Furthermore, self-supervised pre-training improves model robustness as well as in some cases additionally boosts model performance. / Neurala nätverk har visats fungera bra för att lösa visionsbasesarade problem med datorer, särskilt inom bildsegmentering, där operationer utförs på en per pixelnivå. Att använda djupinlärning kan minska tid och ansträngning jämfört med manuell segmentering. Prestandan för dessa metoder är dock beror på kvaliteten och kvantiteten på den tillgängliga datan, vilket är kostsamt och tidskrävande att få fram. I detta arbete behandlar vi problemet om kostsam dataannotering genom att undersöka mer effektiva tillvägagångssätt för att träna dessa modeller på mindre annoterad data genom en kombination av självövervakad förträning och active learning - som kan användas för att finna de mest informativa träningspunkterna. Experiment utfördes med hjälp av datasetten Gland Segmentation och BraTS 2020. Resultaten indikerar attactive learning kan öka prestandan för båda datamängderna när endast ett fåtal datapunkter har annoterats och används för träning. Dessutom förbättrar självövervakad pre-training modellens robusthet och kan i vissa fall öka modellprestandan.
182

Team-Based Learning Approach for the Delivery of Over-the-counter Module in the Faculty of Pharmacy in Jordan

Basheer, H.A., Isreb, Mohammad, Batarseh, Y.S., Tweddell, Simon 17 June 2022 (has links)
Yes / Team-based learning is an active learning strategy that focuses on student’s engagement, development of critical thinking, and transferable skills needed in the workplace. While many pharmacy faculties around the world have applied team-based learning into their curriculums, the implementation of team-based learning into the Middle East is still in the experimental phase and poses its own challenges. This reflective statement elaborates on our experience and feedback of implementing team-based learning for the first time at the pharmacy faculty of Zarqa University in Jordan through the delivery of over-the-counter module.
183

The effect of an active learning approach on grade 11 learners' achievement in newton's laws of motion : a case study of a school in the Eastern Cape

Aboagye, Isaac Baohene January 2012 (has links)
ABSTRACT The aim of this study was to investigate the effect of an active learning approach (ALA) on the achievement of 11 th grade learners in Newton’s laws of motion, The case study was done in one school by comparing the achievement of learners in Newton’s laws of motion through an Active Learning Approach (ALA) with that of learners taught through Traditional Direct I nstruction (TDI) and to determine whether learners taught with ALA retained the material better than those taught with TDI. Two grade 11 classes in one school in the Queenstown District of the Eastern Cape were selected on their performance in two differen t tests and used as case study . The Force Concept Inventory was used to determine the achievements and retention of knowledge of the two groups. The effect of the active lear ning approach on the treatment group was also measured by ask ing each learner in t he group to complete a learner assessment of instruction form. The treatment group was also subjected to a classroom group interview. T he following information emerged from the study: i) Learners taught using the ALA achieved significantly better in FCI pos t - test than those taught with traditional direct instruction. ii) In the retention of knowledge test, the mean score of the learners taught using the ALA was 4.8% higher than those taught with TDI although insignificant. iii) Learners subjected to the ALA liked the instructional approach and as such put in extra time to learn. The findings suggest that the active learning approach had positive effect on the achievement of the Grade 11 learners and thus, can be adapted to enhance learning in the classroom. / Physics
184

Active learning in the literacy learning programme of the foundation phase in Curriculum 2005

Ebrahim, Hasina Banu 04 1900 (has links)
This study focuses on the concept of Active Learning (AL) and the related concept Active Leamer Participation (ALP) as it features in the Literacy Learning Programme of the Foundation Phase of Curriculum 2005. The aim of the action research project, conducted at four schools in the Durban district of K waZulu- Natal, was to find a model of AL in order to provide guidance on teaching for ALP. The study involved the researcher working collaboratively with five Foundation Phase educators over a period of four months. Results of the study indicated that teaching in the sequential stages of classbuilding and teambuilding, whole class discussion, group work and individual work increases learners' active participation and ownership in terms of the learning experience. These stages form the model of active learning. Due to the spirit of camaraderie and partnership that developed in each stage, the research team is inclined to call it "The Tirisano Model of Active Learning". / Educational Studies / M. Ed. (Didactics)
185

Assessing the effects of augmented reality on the spatial skills of postsecondary construction management students in the U.S.

Kim, Jeff 27 May 2016 (has links)
There is a continual challenge within the construction industry to meet schedule, budget, and quality expectations. At the same time, there is an underlying problem where the older and more experienced workforce is retiring from industry at a faster rate than the newer workforce can replace them. As the more experienced workforce departs from the industry, they are taking with them much-needed skills and experience that fail to get transitioned to the newer and less experienced workforce. Among these skills are spatial skills. The construction industry has already caught on that this is a serious problem that they must contend with, and so, they have looked to the postsecondary institutions to help resolve it. However, the postsecondary institutions have a problem of their own, whereby they commonly default to passive teaching techniques that are not well suited to teaching spatial skills. So, therefore, there is a need to graduate construction management students with better spatial skills in order to meet the necessities of industry. Along with this, is the need for academia to reconsider teaching styles to better train spatial skills. Spatial skills, it has been found, are better retained when active and collaborative teaching engagements are arranged. Therefore, identifying and testing a practical and non-interfering classroom tool that students can easily use, would be the most favorable way to overcome academia’s tendency towards passive teaching. Spatial skills are needed in every part of the construction industry. In fact, everyday simple tasks require spatial skills and while these skills are honed over time, more refined skills, capable of interpreting abstract space, are required to assemble a complex construction project. Construction projects are getting more complex and often the design involves some measure of abstract thinking. Teaching these abstract-based spatial skills in postsecondary institutions has typically been done through drafting and plan reading courses, with some success. However, the need from industry is not being fully met with these skills and so an alternative solution is recommended. While Building Information Modeling (BIM) has become an adequate solution to aid in the understanding and planning of highly abstract designs, successfully using it requires excellent spatial skills. Consequently, it would be advantageous if those spatial skills were developed before students were introduced to BIM. Augmented reality is a collection of technologies that allows a user to view the “real” world with additional information that is intended to provide a better understanding of what is being observed. Augmented reality already has applications in many industries and is fast becoming a proven technology. With the availability of smaller and more powerful consumer mobile devices, augmented reality has the potential of becoming a more ubiquitous and practical tool. Recognizing that this technology can be practical, non-interfering, and known by the masses makes it an excellent solution for the classroom. Therefore, this research will study the use of an augmented reality tool to determine if there is an improvement of spatial skills in terms of accuracy, time to execute, and the retention of concepts over time. Furthermore, a separate analysis will be conducted to determine if the teaching tool is a benefit or disruption to the overall learning experience.
186

Enabling organisational knowledge through action learning : an epistemological study

Van Niekerk, Herman J. 12 1900 (has links)
Thesis (PhD)--Universiteit van Stellenbosch, 2004. / ENGLISH ABSTRACT: Key words: Organisational knowledge, pluralistic epistemology, action learning, systems theory, structuration theory, organisational learning, knowledge management. In today's competitive environment the value and importance of knowledge as an organisational resource is considered to be a key element and source of power. Knowledge is regarded as the single most important source of core competence to ensure competitiveness and long term sustainability. The value of most products and services now depends on knowledge-based intangibles and many organisational theorists argue that strategy formulations should be built on a resource-based theory. The challenge for many organisations is therefore how to enable organisational knowledge and how to increase their organisational learning capacity and performance. Following a multi-disciplinary approach, this study critically evaluates and interprets existing theories on action and systems thinking. The traditional positivist paradigm no longer answers to the needs of a post-modem paradigm and corporate epistemologists and practitioners alike are in search of a new paradigm on how to construct organisational knowledge. Drawing on Habermasian theory of communicative action, as well as Parsons' general theory of action and Giddens' structuration theory, I argue that the construction of knowledge happens in a pluralistic manner, in contrast with traditional approaches which support a paradigm informed by a singular epistemology. A pluralistic approach to the development of knowledge, in relation to a Habermasian theory of communicative action which emphasises the importance of communication and which integrates action and systems theory, is therefore proposed. Constitutive features of organisational knowledge, such as deliberation, knowledge leadership, organisational culture and technology, are identified and analysed. Action learning has been adopted by a number of leading international comparues as a learning methodology. However, action learning has seemingly not been grounded in a defensible epistemological framework. In redescribing action learning, this study explores epistemological foundations of action learning in an attempt to provide corporate epistemologists with a defensible epistemological framework which promotes pluralism and constitutive features of organisational knowledge. A framework for organisational learning and knowledge construction, the Pluralistic Action Learning Systems theory (pALS), is suggested as an improved model of organisational learning suitable for implementation in a post-modem era. This framework incorporates the primary "technical" elements of the learning process, namely problem identification, collection of information, analysis and interpretation, application/use and reflection, as well as organisational enablers inherent in collaborative learning. Organisational knowledge is therefore seen as the outcome of a learning process which occurs at the individual, social and organisational system levels. Organisational knowledge is also constituted by features such as communication, knowledge leadership and trust which are essential in a collaborative learning environment. Knowledge is therefore not constructed through a single paradigm, but socially constructed through a pluralistic epistemology. Organisational knowledge is the outcome of organisational learning and such an organisational learning process is enabled by an action learning approach. An empirical study is conducted which is based on a forty-point questionnaire. The sample size is 120 part-time MBA students who are enrolled for an action learning management development programme and who have all been theoretically and practically exposed to an action learning programme. The findings of the empirical study conclude that the construction of knowledge happens in a pluralistic manner and that an organisational epistemology should be shaped by a pluralistic framework if it were to be successful in a post-modem business environment. It proposes that action learning, which is shaped by a pluralistic epistemology grounded in the Habermasian theory of communicative action, provides a defensible framework to enhance organisational knowledge through a collaborative learning approach fostering values such as deliberation, trust and openness. / AFRIKAANSE OPSOMMING: Sleutel woorde: Organisasiekennis, pluralistiese epistemologie, aksieleer, stelseldenke, strukturasie teorie, organisasieleer, kennisbestuur. Die waarde en belangrikheid van kennis in vandag se vinnige veranderende wêreld word beskou as van kritiese waarde en as die enkele mees belangrike element van kompetisie om lang termyn volhoubaarheid te bewerkstellig. In die hedendaagse korporatiewe omgewing word die waarde van die meeste produkte en dienste gebaseer op ontasbare elemente soos onder andere kennis. Korporatiewe strategeë argumenteer derhalwe dat korporatiewe strategie gevolglik op 'n vermoëns-strategie gebaseer moet word. Vir baie maatskappye is die uitdaging dus hoe kennis konstrueer moet word en hoe maatskappye hulle vermoëns moet verbeter om kennisorganisasies te word. Hierdie studie volg 'n multi-disiplinêre benadering wat bestaande aksie- en stelseldenke teorieë krities evalueer en interpreteer. Die tradisionele positivistiese raamwerk beantwoord nie aan die vereistes van 'n post-moderne paradigma nie en beide korporatiewe epistemoloeë en praktisyns is op soek na nuwe wyses hoe om organisasiekennis te konstrueer. Deur gebruik te maak van Parsons se algemene aksie teorie, en in besonder Habermas se teorie van kommunikatiewe aksie en Giddens se strukturasieteorie, argumenteer ek dat die konstruksie van kennis op 'n veeldoelige wyse plaasvind, in teenstelling met die tradisionele benadering wat 'n raamwerk aanbeveel wat op 'n enkelvoudige teorie van kennis gebaseer is. 'n Pluralistiese benadering met betrekking tot die ontwikkeling van kennis, in ooreenstemming met Habermas se teorie van kommunikatiewe aksie en gesteun deur aksie- en stelsels teorie, word derhalwe aanbeveel. Kenmerkende eienskappe van organisasie kennis soos, uitgebreide dialoog, kennisleierskap, organisasiekultuur en tegnologie word ook geidentifiseer en ontleed. Aksieleer is deur verskeie toonaangewende internasionale maatskappye aanvaar as 'n leer metodologie. Dit wil egter voorkom asof aksieleer nie in 'n epistemologiese raamwerk gegrond is nie. Deur aksieleer te herbeskryf ondersoek hierdie studie epistemologiese gronde van aksieleer in 'n poging om korporatiewe epistemoloeë met 'n verdigbare teoretiese kennisraamwerk toe te rus. 'n Raamwerk vir organisasie leer en die konstruksie van kennis, die Pluralistiese Aksieleer Stelsels (pALS) raamwerk, word derhalwe aanbeveel as 'n verdedigbare model wat aan die eise van 'n postmoderne samelewing beantwoord. Hierdie raamwerk sluit die primêre tegniese elemente van die leerproses in, te wete: probleem identifisering, die inwin van informasie, analisering en interpretasie van informasie, aanwending en gebruik van informasie en refleksie. Hierdie proses word verder ondersteun deur aspekte wat organisasieleer vergemaklik binne spanverband. Organisasieleer word dus beskou as die uitkoms van 'n leerproses wat bogenoemde elemente bevat en wat gebaseer is op 'n leeromgewing wat samewerking bevorder. Organisasiekennis word derhalwe gesien as die uitkoms van 'n leerproses wat op die individuele, sosiale en organisasie vlakke geskied. So 'n leerproses word bevorder en vergemaklik deur 'n aksieleer proses. Organisiekennis word ook gekenmerk deur eienskappe soos kommunikasie en kennisleierskap wat binne 'n saamwerk leeromgewing as noodsaaklik geag word. Kennis word dus nie deur 'n enkelvoudige raamwerk konstrueer nie, maar word ondersteun deur 'n veelvoudige epistemologie. Die empiriese studie is gebaseer op 'n veertigpunt vraelys. Die ondersoekgroep is 120 :MBA studente wat vir 'n aksieleer bestuursontwikkelingsprogam ingeskryf is en wat beide teoreties en prakties aan aksieleer blootgestel is. Die bevindings van die studie dui daarop dat kennis nie op 'n enkelvoudige wyse geskep word nie, maar wel deur van verskeie teorieë van kennis gebruik te maak. Die bevindings van die studie beveel aan dat aksieleer, as 'n pluralistiese teorie van kennis gegrond in die denke van Habermas, 'n verdedigbare raamwerk verskaf wat organisasieleer en die konstruksie van kennis bevorder deur 'n leeromgewing waarin waardes soos vertroue, openlikheid en kommunikasie bevorder word.
187

Transformative learning : an exploratory analysis of theory and practice in a study and thinking skills programme

Kilpin, Elsa Margaretha 12 1900 (has links)
Thesis (MEd)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: Many students that embark on higher education do not have study and thinking skills that are sufficiently well developed in order for them to become autonomous, selfdirected learners. This is partly due to the fact that the historically authoritarian and rigid approaches to teaching in some schools have discouraged independent thought. Other contributory factors such as negative beliefs, attitudes and dispositions, and distorted concepts of the self and of learning, also prevent effective learning from taking place. The focus of this research is a study and thinking skills programme. This programme is part of a four week bridging course for freshmen at the University of Stellenbosch. It is based on a comprehensive rationale derived from cognitive education theory, comprising a number of well known theorists such as Piaget, Vygotsky, Feuerstein and Lozanov. This is further supplemented by instruments from authors in the field of thinking skills (de Bono, Buzan). The purpose of this research was to identify elements of the programme which might be responsible for aspects of transformative learning, as defined by Mezirow in his Transformative Learning Theory. These aspects initially became apparent from students' responses in post-programme evaluations. The responses represented an unexpected outcome, as Mezirow's theory was not represented in the programme's rationale. Eight criteria were developed from Mezirow's theory, operationalised as questions, and then utilized to assess transformative learning in the context of the programme. In a conceptual analysis, four categories of the programme (the rationale, the objectives, the course material and implementation procedures) were compared and contrasted with criteria from Transformative Learning Theory. From this analysis it was apparent that several criteria of Transformative Learning Theory were present in the programme: it facilitated learning in both instrumental and communicative domains; it provided opportunities to explore meaning structures and to investigate distorted meaning perspectives; and it instigated disorientating or conflicting experiences with regard to these. Some criteria were absent from the programme in that it failed to promote rational discourse according Mezirow's definition, it did not adequately promote reflection on premises, and it did not intentionally address the transformation of meaning perspectives. These three omissions may be traced to the lack of an "adult learning" focus in the programme's theoretical structure. Despite this, a number of parallels were identified which may explain the representation of Mezirow's criteria in the programme, and hence the students' responses. Conclusions are drawn regarding a theoretically justified view of transformative learning in the context of the Study and Thinking Skills (S&TS) programme, and practical implications for educators are explained. Finally, recommendations are made for enhancing trans formative learning within the Study and Thinking Skills (S&TS) programme, and for the design of similar programmes. Recommendations are also proposed for further research in this area which, in the contemporary South African educational context, clearly deserves more attention in adult education and related settings. / AFRIKAANSE OPSOMMING: Talle studente wat tot hoer onderwys toetree se studie en denkvaardighede is me voldoende ontwikkeld om as outonome, selfgerigte leerders sukses te kan behaal nie. Dit is deels toe te skryf aan die outoritere en rigiede benaderings tot onderwys in sommige skole, wat selfstandige denke ontmoedig. Daar is egter ook ander belemmerende faktore soos studente se negatiewe houdings en verkeerde opvattings van leer en van hulself wat verhinder dat effektiewe leer plaasvind. Die fokus van hierdie navorsing is 'n Studie- en Denkvaardigheidprogram (S&TS). Hierdie program vorm deel van 'n vier week lange oorbruggingsprogram vir eerstejaarstudente aan die Universiteit van Stellenbosch. Die program is gebaseer op 'n omvattende rasionaal vanuit die kognitiewe opvoedkunde perspektief wat die werk van 'n aantal bekende teoretici (Piaget, Vygotsky, Feuerstein en Lozanov) insluit en word aangevul met oefeninge deur outeurs in die veld van denkvaardighede (De Bono en Buzan). Die doel van die navorsmg was om elemente van die program te identifiseer wat verantwoordelik kon wees vir aanduidings van transformatiewe leer, soos gedefinieer deur Mezirow in sy Transformatiewe Leerteorie. Hierdie aanduidings spruit uit studente se response tydens evalueringsessies na afloop van die program. Transformatiewe leeruitkomste was onverwags, omdat Mezirow se teorie nie verteenwoordig was in die rasionaal waarvolgens die program ontwerp is nie. Agt kriteria wat uit Mezirow se teorie ontwikkel kon word, is geoperasionaliseer en in vraagvorm gebruik om die inhoud van die program te analiseer. Die kriteria is as verteenwoordigend van transformatiewe leer in die konteks van 'n studie en denkvaardigheidsprogram beskou. In die analise van die inhoud is vier kategoriee van die program (die rasionaal, die doelstellings, die kursusmateriaal en die implementerings-prosedures) vergelyk en gekontrasteer met die kriteria vanuit die Transformatiewe Leerteorie. Uit hierdie analise het geblyk dat die program aan sekere kriteria voldoen, naamlik dat dit leer in be ide die kommunikatiewe en intrumentele domeine fasiliteer; geleenthede skep om betekenisstrukture te verken en versteurde betekenisperspektiewe te ondersoek; en dat dit disorienterende of konflikterende ervarings veroorsaak met betrekking tot bestaande betekenisstrukture en -perspektiewe. Sommige kriteria was glad nie verteenwoordig in die program nie. Die program het nie daarin geslaag om rasionele diskoers, volgens Mezirow se definisie daarvan, te ontlok nie.; dit het nie voldoende reflektering met betrekking tot onderliggende aannames aangemoedig nie en dit het nie doelbewus die transformasie van betekenisprespektiewe bevorder nie. Hierdie drie weglatings uit die program mag verband hou met die feit dat die teoretiese onderbou van die program nie op volwassene leer fokus nie. Ten spyte hiervan is daar egter steeds 'n aantal ooreenkomste tussen die kognitiewe ontwikkelingsteoriee en Mezirow se transformatiewe leerteorie geidentifiseer wat die verteenwoordiging van Mezirow se teorie in die program en dus die studente se response moontlik kan verklaar. Gevolgtrekkings met betrekking tot 'n teoreties geregverdigde beskouing van transformatiewe leer in die konteks van die Studie- en Denkvaardigheidprogram en die praktiese implikasies hiervan vir opvoeders, word beskryf. Ten slotte word aanbevelings gemaak om transformatiewe leer in die program te bevorder en vir die ontwerp van soortgelyke progamme.
188

Active learning in cost-sensitive environments

Liu, Alexander Yun-chung 21 June 2010 (has links)
Active learning techniques aim to reduce the amount of labeled data required for a supervised learner to achieve a certain level of performance. This can be very useful in domains where unlabeled data is easy to obtain but labelling data is costly. In this dissertation, I introduce methods of creating computationally efficient active learning techniques that handle different misclassification costs, different evaluation metrics, and different label acquisition costs. This is accomplished in part by developing techniques from utility-based data mining typically not studied in conjunction with active learning. I first address supervised learning problems where labeled data may be scarce, especially for one particular class. I revisit claims about resampling, a particularly popular approach to handling imbalanced data, and cost-sensitive learning. The presented research shows that while resampling and cost-sensitive learning can be equivalent in some cases, the two approaches are not identical. This work on resampling and cost-sensitive learning motivates a need for active learners that can handle different misclassification costs. After presenting a cost-sensitive active learning algorithm, I show that this algorithm can be combined with a proposed framework for analyzing evaluation metrics in order to create an active learning approach that can optimize any evaluation metric that can be expressed as a function of terms in a confusion matrix. Finally, I address methods for active learning in terms of different utility costs incurred when labeling different types of points, particularly when label acquisition costs are spatially driven. / text
189

Interactive image search with attributes

Kovashka, Adriana Ivanova 18 September 2014 (has links)
An image retrieval system needs to be able to communicate with people using a common language, if it is to serve its user's information need. I propose techniques for interactive image search with the help of visual attributes, which are high-level semantic visual properties of objects (like "shiny" or "natural"), and are understandable by both people and machines. My thesis explores attributes as a novel form of user input for search. I show how to use attributes to provide relevance feedback for image search; how to optimally choose what to seek feedback on; how to ensure that the attribute models learned by a system align with the user's perception of these attributes; how to automatically discover the shades of meaning that users employ when applying an attribute term; and how attributes can help learn object category models. I use attributes to provide a channel on which the user of an image retrieval system can communicate her information need precisely and with as little effort as possible. One-shot retrieval is generally insufficient, so interactive retrieval systems seek feedback from the user on the currently retrieved results, and adapt their relevance ranking function accordingly. In traditional interactive search, users mark some images as "relevant" and others as "irrelevant", but this form of feedback is limited. I propose a novel mode of feedback where a user directly describes how high-level properties of retrieved images should be adjusted in order to more closely match her envisioned target images, using relative attribute feedback statements. For example, when conducting a query on a shopping website, the user might state: "I want shoes like these, but more formal." I demonstrate that relative attribute feedback is more powerful than traditional binary feedback. The images believed to be most relevant need not be most informative for reducing the system's uncertainty, so it might be beneficial to seek feedback on something other than the top-ranked images. I propose to guide the user through a coarse-to-fine search using a relative attribute image representation. At each iteration of feedback, the user provides a visual comparison between the attribute in her envisioned target and a "pivot" exemplar, where a pivot separates all database images into two balanced sets. The system actively determines along which of multiple such attributes the user's comparison should next be requested, based on the expected information gain that would result. The proposed attribute search trees allow us to limit the scan for candidate images on which to seek feedback to just one image per attribute, so it is efficient both for the system and the user. No matter what potentially powerful form of feedback the system offers the user, search efficiency will suffer if there is noise on the communication channel between the user and the system. Therefore, I also study ways to capture the user's true perception of the attribute vocabulary used in the search. In existing work, the underlying assumption is that an image has a single "true" label for each attribute that objective viewers could agree upon. However, multiple objective viewers frequently have slightly different internal models of a visual property. I pose user-specific attribute learning as an adaptation problem in which the system leverages any commonalities in perception to learn a generic prediction function. Then, it uses a small number of user-labeled examples to adapt that model into a user-specific prediction function. To further lighten the labeling load, I introduce two ways to extrapolate beyond the labels explicitly provided by a given user. While users differ in how they use the attribute vocabulary, there exist some commonalities and groupings of users around their attribute interpretations. Automatically discovering and exploiting these groupings can help the system learn more robust personalized models. I propose an approach to discover the latent factors behind how users label images with the presence or absence of a given attribute, from a sparse label matrix. I then show how to cluster users in this latent space to expose the underlying "shades of meaning" of the attribute, and subsequently learn personalized models for these user groups. Discovering the shades of meaning also serves to disambiguate attribute terms and expand a core attribute vocabulary with finer-grained attributes. Finally, I show how attributes can help learn object categories faster. I develop an active learning framework where the computer vision learning system actively solicits annotations from a pool of both object category labels and the objects' shared attributes, depending on which will most reduce total uncertainty for multi-class object predictions in the joint object-attribute model. Knowledge of an attribute's presence in an image can immediately influence many object models, since attributes are by definition shared across subsets of the object categories. The resulting object category models can be used when the user initiates a search via keywords such as "Show me images of cats" and then (optionally) refines that search with the attribute-based interactions I propose. My thesis exploits properties of visual attributes that allow search to be both effective and efficient, in terms of both user time and computation time. Further, I show how the search experience for each individual user can be improved, by modeling how she uses attributes to communicate with the retrieval system. I focus on the modes in which an image retrieval system communicates with its users by integrating the computer vision perspective and the information retrieval perspective to image search, so the techniques I propose are a promising step in closing the semantic gap. / text
190

Exploring the flipped classroom in a Hong Kong secondary school

Tong, Tracy January 2014 (has links)
This study examines the implementation of the flipped classroom model in a local secondary school in Hong Kong. The flipped classroom is a relatively new educational model requiring teachers to invert the time students spend on lectures and the time students spend on homework. Although several studies conducted on this approach show improvements to student achievement as well as positive views from participating educators, parents and most students, there has been little research done based in Asian schools. For this design study, four geography classes of secondary one students in a local Hong Kong school were “flipped” for one full school term (4 months). Throughout the term, learning resources were posted to online educational platforms for students to access at home, and the teacher developed interactive activities for class time. This paper analyzes data from various summative assessments, statistics from the online platforms, student posts, video footage from the class, responses to a student survey and a teacher interview to examine four elements of the flipped classroom: the nature of the learning environment created to flip the classroom in a local Hong Kong secondary school; whether students could achieve or potentially improve outcomes of the course through flipped learning; whether flipped learning stimulated engagement from students with a particular focus on social constructivist behaviors; and, the sustainability of flipped teaching in a local Hong Kong school. / published_or_final_version / Education / Master / Master of Education

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