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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.
241

Decoupled uplink-downlink user association in full-duplex small cell networks

Sekander, Silvia January 1900 (has links)
In multi-tier cellular networks, user performance is largely a ected by the varying transmit powers, distances, and non-uniform tra c loads of di erent base stations (BSs) in both the downlink (DL) and uplink (UL) directions of transmission. In presence of such heterogeneity, decoupled UL-DL user association (DUDe), which allows users to associate with di erent BSs for UL and DL transmissions, can be used to optimize network performance. Again, in-band full-duplex (FD) communi- cation is considered as a promising technique to improve the spectral e ciency of future multi-tier fth generation (5G) cellular networks. Nonetheless, due to severe UL-to-DL and DL-to-UL interference issues arising due to FD communications, the performance gains of DUDe in FD multi-tier networks are inconspicuous. To this end, this thesis develops a comprehensive framework to analyze the usefulness of DUDe in a full-duplex multi-tier cellular network. We rst formulate a joint UL and DL user association problem (with the provision of decoupled association) that maximizes the sum-rate for UL and DL transmission of all users. Since the formulated problem is a mixed-integer non-linear programming (MINLP) problem, we invoke approxi- mations and binary constraint relaxations to convert the problem into a Geometric Programming (GP) problem that is solved using Karush-Kuhn-Tucker (KKT) opti- mality conditions. Given the centralized nature and complexity of the GP problem, the solution of which serves as the upper bound for any sub-optimal solution, we formulate a distributed two-sided iterative matching game and develop a solution to obtain the solution of the game. In this game, the users and BSs rank one another using preference metrics that are subject to the externalities (i.e., dynamic interfer- ence conditions). The solution of the game is guaranteed to converge and provides Pareto-e cient stable associations. Finally, we derive e cient light-weight versions of the iterative matching solution, i.e., non-iterative matching and sequential UL-DL matching algorithms. The performances of all the solutions are critically evaluated in terms of aggregate UL and DL rates of all users, the number of unassociated users, and the number of coupled/decoupled associations. Simulation results demonstrate the e cacy of the proposed algorithms over the centralized GP solution as well as traditional coupled and decoupled user association schemes. / October 2016
242

Webb Couture : En studie om hur modedesign kan inspirera och förändra webbdesignprocessen för att utmana User Experience standarder / Web Couture : A study about how fashiondesign can inspire and change the web design process in order to challange User Experience standards

Carlfjord, Adam, Gustavsson, Henrik January 2015 (has links)
Webbdesign är ett hantverk med potential till oändlig variation och oräkneliga möjligheter, men det är även en process styrd av standarder och förhållningssätt för att optimera resultatet för slutanvändaren. Begrepp så som user experience och framför allt user experience design har i och med utvecklingen blivit allt viktigare aktörer inom webbdesign. Samtidigt som de underlättar i utvecklingsprocessen genom att diktera hur design bör utformas, skapar de inte också då begränsningar av potentialen för webbdesign? Antalet variationer och möjligheter minskar drastiskt när webbdesigners anpassar sig efter dessa standarder. Den här undersökningen syftar till att utveckla nya metoder och strategier för att främja innovativ webbdesign och undersöka hur modebranschens konstanta strävan efter innovation skulle kunna inspirera och kanske till och med förändra webbdesign utvecklingen. Genom att bryta ner, analysera och sammanfoga designprocesserna för haute couture och webbdesign skapas en designmetod som ger medvetenhet i designval och hjälper att ifrågasätta standarder samt att undersöka alternativa lösningar. Designmetoden kallar vi Webb couture och är ett resultat av undersökningens teoretiska efterforskningar kring user experience och haute couture, designmetoden tillämpas även praktiskt i gestaltningen av undersökningen. / Web design is a craft with unlimited potential for variations and possibilities, but it is also a process controlled by standards and guidelines to optimize results for the end-user. Concepts like User Experience and User Experience Design have through the development of the field become actors of great influence in web design. While they facilitate the development process by dictating how design should be designed, does it not also create limitations to the true potential of web design? The total number of variations and possibilities is reduced drastically when a web designer applies such standards. The goal of this study is to develop new methods and strategies to create innovative web design and to investigate how the fashion industry’s constant quest for innovation could be applied to transform web design. Through breaking down, analyzing and merging the design processes of haute couture and web design we created a design method that gives awareness to the design choices and helps to question the standards and explore alternative solutions. The design method is called Web couture which is a result of the study's theoretical research on user experience and haute couture, this design method is also applied in practice on a web production that is part of the study.
243

An ontology-based approach to Automatic Generation of GUI for Data Entry

Liu, Fangfang 20 December 2009 (has links)
This thesis reports an ontology-based approach to automatic generation of highly tailored GUI components that can make customized data requests for the end users. Using this GUI generator, without knowing any programming skill a domain expert can browse the data schema through the ontology file of his/her own field, choose attribute fields according to business's needs, and make a highly customized GUI for end users' data requests input. The interface for the domain expert is a tree view structure that shows not only the domain taxonomy categories but also the relationships between classes. By clicking the checkbox associated with each class, the expert indicates his/her choice of the needed information. These choices are stored in a metadata document in XML. From the viewpoint of programmers, the metadata contains no ambiguity; every class in an ontology is unique. The utilizations of the metadata can be various; I have carried out the process of GUI generation. Since every class and every attribute in the class has been formally specified in the ontology, generating GUI is automatic. This approach has been applied to a use case scenario in meteorological and oceanographic (METOC) area. The resulting features of this prototype have been reported in this thesis.
244

Ljud- eller oljud : Hur upplevs ljudsättning av  gränssnitt

Wolczynski, Leon January 2016 (has links)
Att presentera information eller påverka användarens upplevelser via ljudsättning av gränssnitt är lågt prioriterat inom systemutveckling. Design av gränssnitt håller den visuella presentationen av information central därtill sammankopplar detta främst med områden som exempelvis användbarhet eller funktionell form. Syftet med denna studie har varit att undersöka hur ljud påverkar upplevelsen samt hur detta skulle kunna implementeras för att förbättra användares upplevelser av internetbaserade gränssnitt. Det vetenskapliga ramverket har sammanställts genom ett artikelunderlag vilket genererat en grundläggande kategorisering. Detta avsåg koppling till ”Estetik”, ”Sonification”, ”Att ljudsätta användardata” samt ”User experience och audio”. Arbetssättet byggde på en metodkombination där ett kvantitativt internetbaserat frågeformulär undersökte områden inom ramverkets kategorisering samt en kvalitativ ”Think-aloud” undersökning där två verksamma systemutvecklare testade en ljudsatt prototyp. Resultatet från den kvalitativa undersökningen visade hur ljudsättning initialt inte värdesatts vid interaktion med ett gränssnitt samtidigt som prototypens ljudsättning inte upplevdes störande eller negativ. Prototypen framkom som ”för” kreativt vinklat vilket återkopplar till ramverkets beskrivning gällande två estetiska huvudspår inom webbdesign. Den kvantitativa analysen framställer hur användbarhet och ordning värdesatts högre än kreativa upplevelser samt att information i gränssnitt inte sågs lämpligt att förmedla via ljud. Slutsatsen inom arbetet ligger vid att ljudsättning av gränssnitt genom ett balanserat formspråk och en bibehållen känsla av kontroll, kan och bör kopplas till användarens interaktion med gränssnittet. Detta kan trots ett viss motstånd användas för att påverka upplevelser, känslor och därtill uppfattad användbarhet inom ett system.
245

Student Modeling in Intelligent Tutoring Systems

Gong, Yue 23 November 2014 (has links)
"After decades of development, Intelligent Tutoring Systems (ITSs) have become a common learning environment for learners of various domains and academic levels. ITSs are computer systems designed to provide instruction and immediate feedback, which is customized to individual students, but without requiring the intervention of human instructors. All ITSs share the same goal: to provide tutorial services that support learning. Since learning is a very complex process, it is not surprising that a range of technologies and methodologies from different fields is employed. Student modeling is a pivotal technique used in ITSs. The model observes student behaviors in the tutor and creates a quantitative representation of student properties of interest necessary to customize instruction, to respond effectively, to engage students¡¯ interest and to promote learning. In this dissertation work, I focus on the following aspects of student modeling. Part I: Student Knowledge: Parameter Interpretation. Student modeling is widely used to obtain scientific insights about how people learn. Student models typically produce semantically meaningful parameter estimates, such as how quickly students learn a skill on average. Therefore, parameter estimates being interpretable and plausible is fundamental. My work includes automatically generating data-suggested Dirichlet priors for the Bayesian Knowledge Tracing model, in order to obtain more plausible parameter estimates. I also proposed, implemented, and evaluated an approach to generate multiple Dirichlet priors to improve parameter plausibility, accommodating the assumption that there are subsets of skills which students learn similarly. Part II: Student Performance: Student Performance Prediction. Accurately predicting student performance is one of the most desired features common evaluations for student modeling. for an ITS. The task, however, is very challenging, particularly in predicting a student¡¯s response on an individual problem in the tutor. I analyzed the components of two common student models to determine which aspects provide predictive power in classifying student performance. I found that modeling the student¡¯s overall knowledge led to improved predictive accuracy. I also presented an approach, which, rather than assuming students are drawn from a single distribution, modeled multiple distributions of student performances to improve the model¡¯s accuracy. Part III: Wheel-spinning: Student Future Failure in Mastery Learning. One drawback of the mastery learning framework is its possibility to leave a student stuck attempting to learn a skill he is unable to master. We refer to this phenomenon of students being given practice with no improvement as wheel-spinning. I analyzed student wheel-spinning across different tutoring systems and estimated the scope of the problem. To investigate the negative consequences of see what wheel-spinning could have done to students, I investigated the relationships between wheel-spinning and two other constructs of interest about students: efficiency of learning and ¡°gaming the system¡±. In addition, I designed a generic model of wheel-spinning, which uses features easily obtained by most ITSs. The model can be well generalized to unknown students with high accuracy classifying mastery and wheel-spinning problems. When used as a detector, the model can detect wheel-spinning in its early stage with satisfying satisfactory precision and recall. "
246

Primary User Emulation Detection in Cognitive Radio Networks

Pu, Di 24 April 2013 (has links)
Cognitive radios (CRs) have been proposed as a promising solution for improving spectrum utilization via opportunistic spectrum sharing. In a CR network environment, primary (licensed) users have priority over secondary (unlicensed) users when accessing the wireless channel. Thus, if a malicious secondary user exploits this spectrum access etiquette by mimicking the spectral characteristics of a primary user, it can gain priority access to a wireless channel over other secondary users. This scenario is referred to in the literature as primary user emulation (PUE). This dissertation first covers three approaches for detecting primary user emulation attacks in cognitive radio networks, which can be classified in two categories. The first category is based on cyclostationary features, which employs a cyclostationary calculation to represent the modulation features of the user signals. The calculation results are then fed into an artificial neural network for classification. The second category is based on video processing method of action recognition in frequency domain, which includes two approaches. Both of them analyze the FFT sequences of wireless transmissions operating across a cognitive radio network environment, as well as classify their actions in the frequency domain. The first approach employs a covariance descriptor of motion-related features in the frequency domain, which is then fed into an artificial neural network for classification. The second approach is built upon the first approach, but employs a relational database system to record the motion-related feature vectors of primary users on this frequency band. When a certain transmission does not have a match record in the database, a covariance descriptor will be calculated and fed into an artificial neural network for classification. This dissertation is completed by a novel PUE detection approach which employs a distributed sensor network, where each sensor node works as an independent PUE detector. The emphasis of this work is how these nodes collaborate to obtain the final detection results for the whole network. All these proposed approaches have been validated via computer simulations as well as by experimental hardware implementations using the Universal Software Radio Peripheral (USRP) software-defined radio (SDR) platform.
247

Management of Big Annotations in Relational Database Management Systems

Ibrahim, Karim 24 April 2014 (has links)
Annotations play a key role in understanding and describing the data, and annotation management has become an integral component in most emerging applications such as scientific databases. Scientists need to exchange not only data but also their thoughts, comments and annotations on the data as well. Annotations represent comments, Lineage of data, description and much more. Therefore, several annotation management techniques have been proposed to efficiently and abstractly handle the annotations. However, with the increasing scale of collaboration and the extensive use of annotations among users and scientists, the number and size of the annotations may far exceed the size of the original data itself. However, current annotation management techniques don’t address large scale annotation management. In this work, we propose three chapters to that tackle the Big annotations from three different perspectives (1) User-Centric Annotation Propagation, (2) Proactive Annotation Management and (3) InsightNotes Summary-Based Querying. We capture users' preferences in profiles and personalizes the annotation propagation at query time by reporting the most relevant annotations (per tuple) for each user based on time plan. We provide three Time-Based plans, support static and dynamic profiles for each user. We support a proactive annotation management which suggests data tuples to be annotated in case new annotation has a reference to a data value and user doesn’t annotate the data precisely. Moreover, we provide an extension on the InsightNotes: Summary-Based Annotation Management in Relational Databases by adding query language that enable the user to query the annotation summaries and add predicates on the annotation summaries themselves. Our system is implemented inside PostgreSQL.
248

Understanding the Effect of Animation and its Speed on User Enjoyment

January 2019 (has links)
abstract: Providing the user with good user experience is complex and involves multiple factors. One of the factors that can impact the user experience is animation. Animation can be tricky to get right and needs to be understood by designers. Animations that are too fast might not accomplish anything and having them too slow could slow the user down causing them to get frustrated. This study explores the subject of animation and its speed by trying to answer the following questions – 1) Do people notice whether an animation is present 2) Does animation affect the enjoyment of a transition? and 3) If animation does affect enjoyment, what is the effect of different animation speeds? The study was conducted using 3 prototypes of an application to order bottled water in which the transitions between different brands of bottled water were animated at 0ms, 300ms and 650ms. A survey was conducted to see if the participants were able to spot any difference between the prototypes and if they did, which one they preferred. It was found that most people did not recognize any difference between the prototypes. Even people who recognized a difference between the prototypes did not have any preference of speed. / Dissertation/Thesis / Masters Thesis Human Systems Engineering 2019
249

Integration of Massive Multiplayer Online Role-Playing Games Client-Server Architectures with Collaborative Multi-User Engineering CAx Tools

Winn, Joshua D. 28 February 2012 (has links)
This research presents a new method for integrating client server architectures that are used for the development of Massive Online Role Playing Games (MMORPG) into multi-user engineering software tools. The new method creates a new architecture named CAx Connect by changing the client-pull-server communication pipeline to a server-push-client communication pipeline, effectively reducing the amount of bandwidth consumed and allowing these tools to utilize multiple server processors for complex calculations. This method was used on the new NX Connect multi-user CAx prototype developed at BYU. The new method provides a road map to further implement this architecture and its services into additional multi-user CAx tools. To demonstrate the effectiveness of this technology, a prototype architecture was built to provide a front end service, a message relay service, and a database insertion service, which were integrated into the current architecture. The front end service provides load balancing of clients, while the feature administration service passes messages throughout the architecture. The database insertion service inserts features passed from the NX Connect client into the database. The results show that this architecture is more efficient and that a scalable architecture was created, successfully demonstrating the integration of this architecture with multi-user CAx tools.
250

Creating and Automatically Grading Annotated Questions

Wood, Alicia Crowder 01 September 2016 (has links)
We have created a question type that allows teachers to easily create questions, helps provide an intuitive user experience for students to take questions, and reduces the time it currently takes teachers to grade and provide feedback to students. This question type, or an "annotated" question, will allow teachers to test students' knowledge in a particular subject area by having students "annotate" or mark text and video sources to answer questions. Through user testing we determined that overall the interface and the implemented system decrease the time it would take a teacher to grade annotated quiz questions. However, there are some limitations based on the way students answered text annotated questions that would require a rewrite of the user interface and system design to decrease the grading time even more for teachers.

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