|
|
Acquiring user preferences for eshop
Smrčka, Zdeněk ; Vojtáš, Peter (advisor) ; Eckhardt, Alan (referee)
Title: Acquiring user preferences for e-shop Author: Zdenek Smrcka Department: The Department of Software Engineering Supervisor: prof. RNDr. Peter Vojtáš, DrSc. Abstract: The goal of this thesis is to create e-shop /in medical domain (sector), but useable in other domains (sectors)/. We use implicit metod for acquiring user preferences. By the help of this method the products are ordered from most preferred to less preferred for registered user. In case that user will choose some interesting category of products, then products are listed from maximum to less preferred in that category. It creates feedback about popularity of products for individual users and the producer gets information about interest of products in the market place and administrator can change positions of products in e-shop base on popularity. Keywords: user preferences, internet shop, user's favorite's products
|
|
|
Univerzální doporučovací systém
Cvengroš, Petr ; Vojtáš, Peter (advisor) ; Dědek, Jan (referee)
Recommender systems are programs that aim to present items like songs or books that are likely to be interesting for a user. These systems have become increasingly popular and are intensively studied by research groups all over the world. In web systems, like e-shops or community servers there are usually multiple data sources we can use for recommending, as user and item attributes, user-item rating or implicit feedback from user behaviour. In the thesis, we present a concept of a Universal Recommender System (Unresyst) that can use these data sources and is domain-independent at the same time. We propose how Unresyst can be used. From the contemporary methods of recommending, we choose a knowledge based algorithm combined with collaborative filtering as the most appropriate algorithm for Unresyst. We analyze data sources in various systems and generalize them to be domain-independent. We design the architecture of Unresyst, describe its interfaces and methods for processing the data sources. We adapt Unresyst to three real-world data sets, evaluate the recommendation accuracy results and compare them to a contemporary collaborative filtering recommender. The comparison shows that combining multiple data sources can improve the accuracy of collaborative filtering algorithms and can be used in systems where...
|
|
| |
|
|
User anotation of web resources using microformats
Toušek, Jiří ; Vojtáš, Peter (advisor) ; Dědek, Jan (referee)
This thesis explores the feasibility of using the principles of user-assisted annotation for semantic annotation of web resources using microformats. The main concept explored is the approach using the user assistance not to mine the data but to create a set of "annotation rules" that could then be used repeatedly to annotate the target data, without requiring further user assistance. The thesis considers multiple ways to represent these annotation rules. An important attribute of this approach is a chance these annotation rules could withstand changes in the data annotated as well as minor changes in the web resource structure. A prototype implementation is created as a part of this thesis on which these concepts are then verified.
|
|
|
Preferencev querying, indexing, optimisation
Horničák, Erik ; Vojtáš, Peter (advisor) ; Ondreička, Matúš (referee)
In this thesis we discuss the issue of searching the best k objects from the multi-users point of view. Every user has his own preferences, which are represented by fuzzy functions and aggregation function. This thesis designs and implements several solutions of searching the best k objects when attributes data are stored on remote servers. It was necessary to modificate existing algorithms for this type of obtaining data. This thesis uses several variants of Fagin algorithm, indexing methods using B+ trees and communication via web services.
|
|
|
User preferences in the domain of web shops
Peška, Ladislav ; Vojtáš, Peter (advisor) ; Eckhardt, Alan (referee)
The goal of the thesis is first to find available information about user preferences, user feedback and their acquisition, processing, storing etc. The collected information is then used for making suggestions / advices for the creating an recommender system for the web shops (with special emphasis on implicit feedback). The following chapters introduces UPComp - our solution of the recommender system for the web shops. The UPComp is written in the programming language PHP and uses MySQL database. The thesis also includes testing of the UPComp on real-user web shop sites slantour.cz and antikvariat-ichtys.cz.
|
|
|
Query languages for the Semantic web
Galgonek, Jakub ; Vojtáš, Peter (referee) ; Yaghob, Jakub (advisor)
The idea of the Semantic Web brings new requirements such as to create and store metadata of documents or resources. Also ability to search in such metadata is needed. Existing query languages for the Semantic Web are unfortunately either too weak or have complicated syntax or semantics. The aim of this thesis is to compare existing Semantic Web query languages and to propose new one considering its expression strength. This comparison is done by juxtapositioning of their approaches to various issues in querying. Such issues are, for example, a basic selection of data, an ability to select data with recursively defined structure, creating data, a way of working with blank nodes, etc. On the basis of this comparison, the Tequila language is proposed. The Tequila is based on named pattern and provide general recursion. This thesis also shows the way how to use Tequila language and further, it compares the Tequila with other query languages.
|
|
|
Modelling n-ary relations in description logics
Blaško, Miroslav ; Vojtáš, Peter (referee) ; Zavoral, Filip (advisor)
DLR is an expressive description logic with support of n-ary relations. Currently, there is no known algorithm for native reasoning within DLR. However there are two approaches that allow to delegate reasoning services of DLR to binary description logics. In this work we de ne new description logic NDL, a subset of DLR, for which we believe that native reasoning can be provided. Based on the existing approaches, we transform NDL to binary description logics for which the current of state-of-art of reasoners exist. New transformations will be analysed both theoretically and empirically. N-ary data for benchmark will be created from existing OWL ontologies by transformation of opposite direction. This benchmark can be used for comparison of native reasoning and reasoning by transformation to binary DLs.
|
|
|
Semantic annotation of data from web resources
Dědek, Jan ; Pokorný, Jaroslav (referee) ; Vojtáš, Peter (advisor)
This work starts with the idea of The Semantic Web. Then basic description logics is introduced with its parallel in a couple of formalisms for building of ontology. In this work, there is shown, how the ontologies are employed in the semantic annotation process and also there are described some projects that use semantic annotation in a practical way. Information extraction methods that help to automatize the semantic annotation process are mentioned. Tools for natural language processing of Czech language are described in detail. A practical experiment shows how these tools can help with extraction of information from plain text. This work also deals with the relationship of natural language processing and formal representation of knowledge in description logics.
|
|
|
Data and Ontologies
Kotowski, Jakub ; Vojtáš, Peter (referee) ; Štěpánek, Petr (advisor)
In the core of current semantic web efforts is the notion of ontology. Although ontologies have been explored since times of the Greek philosopher Aristotle already there is still much to learn in this area. There are many tutorials and introductory texts both into the semantic web as whole and into its individual technologies but the learning curve is still very steep and developers have to seek answers to questions that are often topic of current research or the answer is simply not known yet. Much of these difficulties one encounters at what is often the very first step towards building a semantic web application - creating an ontology. In this work I point out some of the difficulties I encountered myself during the work on an ontology for a Sun Microsystems website. I review current research on the problems and suggest a solution. I particularly analyze the notion of role concepts, suggest an improvment of a normalisation technique which can then be used to avoid some of the role-related problems. I also present the process of creating the example Sun ontology.
|
guest ::
