DBSnap-Eval: Identifying Database Query Construction Patterns

Learning to construct database queries can be a challenging task because students need to learn the specific query language syntax as well as properly understand the effect of each query operator and how multiple operators interact in a query. While some previous studies have looked into the types of database query errors students make and how the availability of expected query results can help to increase the success rate, there is very little that is known regarding the patterns that emerge while students are constructing a query. To be able to look into the process of constructing a query, in this paper we introduce DBSnap-Eval, a tool that supports tree-based queries (similar to SQL query plans) and a block-based querying interface to help separate the syntax and semantics of a query. DBSnap-Eval closely monitors the actions students take to construct a query such as adding a dataset or connecting a dataset with an operator. This paper presents an initial set of results about database query construction patterns using DBSnap-Eval. Particularly, it reports identified patterns in the process students follow to answer common database queries

DBSnap 2: New Features to Construct Database Queries by Snapping Blocks

Block-based environments for creating computer programs have become very useful learning tools in computer science as they enable focusing on the logic of a program rather than on its syntactical details. While most block-based environments support conventional (imperative) instructions, a few tools have been proposed to create database queries. One of these tools is DBSnap, a highly dynamic and open-source tool to create database query trees by dragging and connecting visual blocks representing datasets and database operators. In this paper, we introduce DBSnap 2, an extension of DBSnap that provides a set of improvements to facilitate the creation of simple and complex queries. The improvements include the support of database views (a key database concept), saving and importing queries, inserting, updating, and deleting data, the creation of charts, and various visual improvements. The demonstration of DBSnap 2 will show how the new features simplify the creation of queries and enable the graphical visualization of query results

Generating stable molecules using imitation and reinforcement learning

Chemical space is routinely explored by machine learning methods to discover interesting molecules, before time-consuming experimental synthesizing is attempted. However, these methods often rely on a graph representation, ignoring 3D information necessary for determining the stability of the molecules. We propose a reinforcement learning (RL) approach for generating molecules in Cartesian coordinates allowing for quantum chemical prediction of the stability. To improve sample-efficiency we learn basic chemical rules from imitation learning (IL) on the GDB-11 database to create an initial model applicable for all stoichiometries. We then deploy multiple copies of the model conditioned on a specific stoichiometry in a RL setting. The models correctly identify low energy molecules in the database and produce novel isomers not found in the training set. Finally, we apply the model to larger molecules to show how RL further refines the IL model in domains far from the training data

Ranking Large Temporal Data

Ranking temporal data has not been studied until recently, even though ranking is an important operator (being promoted as a firstclass citizen) in database systems. However, only the instant top-k queries on temporal data were studied in, where objects with the k highest scores at a query time instance t are to be retrieved. The instant top-k definition clearly comes with limitations (sensitive to outliers, difficult to choose a meaningful query time t). A more flexible and general ranking operation is to rank objects based on the aggregation of their scores in a query interval, which we dub the aggregate top-k query on temporal data. For example, return the top-10 weather stations having the highest average temperature from 10/01/2010 to 10/07/2010; find the top-20 stocks having the largest total transaction volumes from 02/05/2011 to 02/07/2011. This work presents a comprehensive study to this problem by designing both exact and approximate methods (with approximation quality guarantees). We also provide theoretical analysis on the construction cost, the index size, the update and the query costs of each approach. Extensive experiments on large real datasets clearly demonstrate the efficiency, the effectiveness, and the scalability of our methods compared to the baseline methods.Comment: VLDB201

TimeNotes: A Study on Effective Chart Visualization and Interaction Techniques for Time-Series Data

Collecting sensor data results in large temporal data sets which need to be visualized, analysed, and presented. One dimensional time-series charts are used, but these present problems when screen resolution is small in comparison to the data. This can result in severe over-plotting, giving rise for the requirement to provide effective rendering and methods to allow interaction with the detailed data. Common solutions can be categorized as multi-scale representations, frequency based, and lens based interaction techniques. In this paper, we comparatively evaluate existing methods, such as Stack Zoom [15] and ChronoLenses [39], giving a graphical overview of each and classifying their ability to explore and interact with data. We propose new visualizations and other extensions to the existing approaches. We undertake and report an empirical study and a field study using these techniques

Virtual Campus for the University of Jaume I, Castelló, Spain: 3D Modelling of the Campus Buildings using CityEngine

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.The Virtual Smart Campus for the University of Jaume I – Visca Uji – is a project that aims to transform the University of Jaume I (UJi) into a “Smart Campus”. Several applications are part of the Smart Campus such as Uji Place Finder, Energy Consumption, Routes, Resources Management, and Indoor Mapping. Part of this project is the creation of the 3D model of the university buildings using Esri software — City Engine. This study analysed two 3D modeling approaches: procedural modeling language (CGA Shape) and manual modeling. The first, Computer Generated Architecture (CGA) shape is an extension of set grammars that have been applied in CG successfully over the years. And the second, CityEngine offers a set of shape creation and editing tools that allows a more intuitive and pragmatic 3D modeling technique. Both approaches have advantages and disadvantages, overall creating a 3D model by using procedural modelling language showed to be the more efficient and pragmatic method

Mobile capture of remote points of interest using line of sight modelling

Recording points of interest using GPS whilst working in the field is an established technique in geographical fieldwork, where the user’s current position is used as the spatial reference to be captured; this is known as geo-tagging. We outline the development and evaluation of a smartphone application called Zapp that enables geo-tagging of any distant point on the visible landscape. The ability of users to log or retrieve information relating to what they can see, rather than where they are standing, allows them to record observations of points in the broader landscape scene, or to access descriptions of landscape features from any viewpoint. The application uses the compass orientation and tilt of the phone to provide data for a line of sight algorithm that intersects with a Digital Surface Model stored on the mobile device. We describe the development process and design decisions for Zapp present the results of a controlled study of the accuracy of the application, and report on the use of Zapp for a student field exercise. The studies indicate the feasibility of the approach, but also how the appropriate use of such techniques will be constrained by current levels of precision in mobile sensor technology. The broader implications for interactive query of the distant landscape and for remote data logging are discussed

Image Retrieval within Augmented Reality

Die vorliegende Arbeit untersucht das Potenzial von Augmented Reality zur Verbesserung von Image Retrieval Prozessen. Herausforderungen in Design und Gebrauchstauglichkeit wurden für beide Forschungsbereiche dargelegt und genutzt, um Designziele für Konzepte zu entwerfen. Eine Taxonomie für Image Retrieval in Augmented Reality wurde basierend auf der Forschungsarbeit entworfen und eingesetzt, um verwandte Arbeiten und generelle Ideen für Interaktionsmöglichkeiten zu strukturieren. Basierend auf der Taxonomie wurden Anwendungsszenarien als weitere Anforderungen für Konzepte formuliert. Mit Hilfe der generellen Ideen und Anforderungen wurden zwei umfassende Konzepte für Image Retrieval in Augmented Reality ausgearbeitet. Eins der Konzepte wurde auf einer Microsoft HoloLens umgesetzt und in einer Nutzerstudie evaluiert. Die Studie zeigt, dass das Konzept grundsätzlich positiv aufgenommen wurde und bietet Erkenntnisse über unterschiedliches Verhalten im Raum und verschiedene Suchstrategien bei der Durchführung von Image Retrieval in der erweiterten Realität.:1 Introduction 1.1 Motivation and Problem Statement 1.1.1 Augmented Reality and Head-Mounted Displays 1.1.2 Image Retrieval 1.1.3 Image Retrieval within Augmented Reality 1.2 Thesis Structure 2 Foundations of Image Retrieval and Augmented Reality 2.1 Foundations of Image Retrieval 2.1.1 Definition of Image Retrieval 2.1.2 Classification of Image Retrieval Systems 2.1.3 Design and Usability in Image Retrieval 2.2 Foundations of Augmented Reality 2.2.1 Definition of Augmented Reality 2.2.2 Augmented Reality Design and Usability 2.3 Taxonomy for Image Retrieval within Augmented Reality 2.3.1 Session Parameters 2.3.2 Interaction Process 2.3.3 Summary of the Taxonomy 3 Concepts for Image Retrieval within Augmented Reality 3.1 Related Work 3.1.1 Natural Query Specification 3.1.2 Situated Result Visualization 3.1.3 3D Result Interaction 3.1.4 Summary of Related Work 3.2 Basic Interaction Concepts for Image Retrieval in Augmented Reality 3.2.1 Natural Query Specification 3.2.2 Situated Result Visualization 3.2.3 3D Result Interaction 3.3 Requirements for Comprehensive Concepts 3.3.1 Design Goals 3.3.2 Application Scenarios 3.4 Comprehensive Concepts 3.4.1 Tangible Query Workbench 3.4.2 Situated Photograph Queries 3.4.3 Conformance of Concept Requirements 4 Prototypic Implementation of Situated Photograph Queries 4.1 Implementation Design 4.1.1 Implementation Process 4.1.2 Structure of the Implementation 4.2 Developer and User Manual 4.2.1 Setup of the Prototype 4.2.2 Usage of the Prototype 4.3 Discussion of the Prototype 5 Evaluation of Prototype and Concept by User Study 5.1 Design of the User Study 5.1.1 Usability Testing 5.1.2 Questionnaire 5.2 Results 5.2.1 Logging of User Behavior 5.2.2 Rating through Likert Scales 5.2.3 Free Text Answers and Remarks during the Study 5.2.4 Observations during the Study 5.2.5 Discussion of Results 6 Conclusion 6.1 Summary of the Present Work 6.2 Outlook on Further WorkThe present work investigates the potential of augmented reality for improving the image retrieval process. Design and usability challenges were identified for both fields of research in order to formulate design goals for the development of concepts. A taxonomy for image retrieval within augmented reality was elaborated based on research work and used to structure related work and basic ideas for interaction. Based on the taxonomy, application scenarios were formulated as further requirements for concepts. Using the basic interaction ideas and the requirements, two comprehensive concepts for image retrieval within augmented reality were elaborated. One of the concepts was implemented using a Microsoft HoloLens and evaluated in a user study. The study showed that the concept was rated generally positive by the users and provided insight in different spatial behavior and search strategies when practicing image retrieval in augmented reality.:1 Introduction 1.1 Motivation and Problem Statement 1.1.1 Augmented Reality and Head-Mounted Displays 1.1.2 Image Retrieval 1.1.3 Image Retrieval within Augmented Reality 1.2 Thesis Structure 2 Foundations of Image Retrieval and Augmented Reality 2.1 Foundations of Image Retrieval 2.1.1 Definition of Image Retrieval 2.1.2 Classification of Image Retrieval Systems 2.1.3 Design and Usability in Image Retrieval 2.2 Foundations of Augmented Reality 2.2.1 Definition of Augmented Reality 2.2.2 Augmented Reality Design and Usability 2.3 Taxonomy for Image Retrieval within Augmented Reality 2.3.1 Session Parameters 2.3.2 Interaction Process 2.3.3 Summary of the Taxonomy 3 Concepts for Image Retrieval within Augmented Reality 3.1 Related Work 3.1.1 Natural Query Specification 3.1.2 Situated Result Visualization 3.1.3 3D Result Interaction 3.1.4 Summary of Related Work 3.2 Basic Interaction Concepts for Image Retrieval in Augmented Reality 3.2.1 Natural Query Specification 3.2.2 Situated Result Visualization 3.2.3 3D Result Interaction 3.3 Requirements for Comprehensive Concepts 3.3.1 Design Goals 3.3.2 Application Scenarios 3.4 Comprehensive Concepts 3.4.1 Tangible Query Workbench 3.4.2 Situated Photograph Queries 3.4.3 Conformance of Concept Requirements 4 Prototypic Implementation of Situated Photograph Queries 4.1 Implementation Design 4.1.1 Implementation Process 4.1.2 Structure of the Implementation 4.2 Developer and User Manual 4.2.1 Setup of the Prototype 4.2.2 Usage of the Prototype 4.3 Discussion of the Prototype 5 Evaluation of Prototype and Concept by User Study 5.1 Design of the User Study 5.1.1 Usability Testing 5.1.2 Questionnaire 5.2 Results 5.2.1 Logging of User Behavior 5.2.2 Rating through Likert Scales 5.2.3 Free Text Answers and Remarks during the Study 5.2.4 Observations during the Study 5.2.5 Discussion of Results 6 Conclusion 6.1 Summary of the Present Work 6.2 Outlook on Further Wor