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Design and Implementation Issues for Explorative Location-based Applications: The NexusRallye. Daniela Nicklas , Nicola Hönle, Michael Moltenbrey, Bernhard Mitschang GeoInfo 2004, 22. November 2004. Center of Excellence 627: Spatial World Models for Mobile Context-Aware Applications.
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Design and Implementation Issues for Explorative Location-based Applications:The NexusRallye Daniela Nicklas, Nicola Hönle, Michael Moltenbrey, Bernhard Mitschang GeoInfo 2004, 22. November 2004 Center of Excellence 627: Spatial World Models for Mobile Context-Aware Applications Universität Stuttgart, Germany
Overview • Motivation • A task-oriented approach • Sample application: the NexusRallye • Requirements • Data Model • Context management: the Nexus platform • Platform architecture • Access patterns • Lessons learned
cafeteria CS building library examinationoffice A freshmen at the University
Welcome days for CS freshmen • First day: Guided tours • experienced students show the campus to the freshmen • explain the most important things for "survival" • welcome party • Second day: the Campus rally • morning: freshmen teams get sheets of paper with tasks, e.g.: • "How many steps are in the math building from first to eigth level?" • "What is the registration number of the examination on databases?" • "Who is Fabiola and what is she doing in the students lab?" • "Write a short poem on the food offered today in the cafeteria." • afternoon: teams return, jury assesses the answers • winner team gets prize, another party
Features of the rally game • tasks get the players to move around • require location knowledge • require communication with people • reuse of tasks from last year, add new ones • general & specific tasks (university & computer science) • possible benefits of electronic version: • use of existing information spaces (maps, web sites, ...) • easy reuse of tasks • dependency of tasks • case study for location-based applications (research goal)
question task action task ... multiple choice value free text find/goTo task bringTo task ... A task-oriented approach • what types of tasks to support? task • target: • specific/general • stationary/moving
Overview • Motivation • A task-oriented approach • Sample application: the NexusRallye • Requirements • Data Model • Context management: the Nexus platform • Platform architecture • Access patterns • Lessons learned
Requirements for NexusRallye • get benefits: • use of existing information spaces (maps, web sites, ...) • easy reuse of tasks • dependency of tasks • support different types of tasks • support different rallies sharing tasks • automatic scoring (if applicable), else: sending results to the jury (e-mail) • multiplayer game
Use Case • player searches for rallies in her surrounding • player (or team of players) signs up for a rally • player gets initial tasks • dependencies between tasks lead player to (multiple) paths through the rally • after solving enough tasks or a time-out occured, the game ends • player gets result
Association of tasks and rallies • tasks can have more than one location • for different rallies, a task can be relevant at different locations • Solution: concept of Virtual Task Container (VTC) • a rally consists of VTCs • each VTC has a certain visibility area • VTC references tasks to that area, which get available for player if she enters it
Sample Rallye Scenario ? ? 2 ? ? 4 ? ? ? 3 ? ? 1 Campus University of Stuttgart reference virtual task container with visibility area ? rallye area player task
Tasks can lead to each other find Nexus lab cafeteria ? 2 ? go to cafeteria 4 ? ? ? Nexus Lab 3 ? 1 ? Campus University of Stuttgart reference virtual task container with visibility area ? rallye area player task
Designing a rally • choose tasks: • use goTo/bringTo tasks to let users go to certain locations • choose tasks more or less connected • enable different paths through the rally • model VTCs: • associate appropriate tasks • ensure that players always have "something to do" • Easter eggs: VTCs with no prior hint (e.g. moveTo tasks)
VTC pos: Point visibility: Polygon Rallye name: String extent: Polygon Player name: String pos: Point Data Model of NexusRallye contains takes part references … Task ? + library, street, copy machine, cafeteria, ... context model Action Task Question Task
Overview • Motivation • A task-oriented approach • Sample application: the NexusRallye • Requirements • Data Model • Context management: the Nexus platform • Platform architecture • Access patterns • Lessons learned
multiplayer game, common model necessary no reuse of existing context data Nexus platform Context Management • Context model: • map data (buildings, streets, POIs, ...) • user positions (moving objects) • tasks and game related objects (for BringTo-tasks) • Access: queries and events • Design alternatives: • local (on the client) • server-side (one specialized server) • shared (among several servers)
Multimodal Navigation SmartFactory Mobile City Guide Nexus Rallye sensor data The Nexus Vision: Federated World Models Context-aware Applications … GlobalContext Model Federation LocalContext Models Digital Information Spaces ... Digital Libraries WWW
The Nexus Platform: Architecture applicationtier Application B Application A Federation Hoarding Federation Federation Query Component AreaServiceRegister federationtier NavigationService EventService GeoCast register context models: map data, user positions, tasks, ... servicetier ContextServer ContextServer ContextServer
register notification MapService Query Component NavigationService EventService GeoCast notification Value-added Services Queries Events The Nexus Platform: Access Patterns applicationtier Application B Application A Federation Map Service Federation Federation Query Component AreaServiceRegister federationtier NavigationService EventService GeoCast XML interfaces (over SOAP) • simple spatial query language (AWQL) • spatial model exchange language (AWML) • event registration and notification languages(ERL, ENL) • Navigation routes (NRL), Map (MapPL)... servicetier ContextServer ContextServer ContextServer
NexusRallye and Nexus Platform applicationtier Application B NexusRallye Queries: get rallies, get VTC, get tasks Federation Hoarding Query Component AreaServiceRegister federationtier NavigationService Events: OnEnter VTC area, solved moveTo/bringTo EventService GeoCast register ContextServer 1: Campus Model ContextServer 2: VTCs, Rallye-Objects servicetier ContextServer 3: Moving Objects (Players)
Lessons learned • NexusRallye: • good sample application to prove the openess of the Nexus platform • explorative location-based applications: • demand actions from the user by tasks • assumption: • user need time and have to see clear advantage • games can do this (advantage: edutainment) • still pending: user studies to prove acceptability and learning success
Obrigada! www.nexus.uni-stuttgart.de