Social Network Analysis

A multi-dimensional information repository has a plurality of stored data structures; and one or more tags associated with individual ones of the plurality of data structures. The data structures are tagged according to locations and defined regions relative to the surface of the Earth, and a data retrieval system retrieves information from the data structures according to location data accompanying requests for data. In some cases data structures are also tagged relative to time in addition to location and defined regions, and both tags are used in retrieving data structures. An Internet-connected subscription server system using the data repository has a communication module for receiving data requests accompanied by location data and a code set for managing retrieval of information from the data repository in response to the data requests. The system, receiving a data request, uses the location data accompanying the request to determine location in individual ones of pre-defined regions, and uses the pre-defined region information to access data structures and retrieve information related to the pre-defined regions for transmission in response to the data requests.

Internet system for connecting client-travelers with geographically-associated data

There is an increasing interest in creating pervasive games based on emerging interaction technologies. In order to develop touch-less, interactive and augmented reality games on vision-based wearable device, a touch-less motion interaction technology is designed and evaluated in this work. Users interact with the augmented reality games with dynamic hands/feet gestures in front of the camera, which triggers the interaction event to interact with the virtual object in the scene. Three primitive augmented reality games with eleven dynamic gestures are developed based on the proposed touch-less interaction technology as proof. At last, a comparing evaluation is proposed to demonstrate the social acceptability and usability of the touch-less approach, running on a hybrid wearable framework or with Google Glass, as well as workload assessment, user's emotions and satisfaction.

Touch-less interactive augmented reality game on vision-based wearable device

This is the preprint version of our paper on Personal and Ubiquitous Computing. There is an increasing interest in creating pervasive games based on emerging interaction technologies. In order to develop touch-less, interactive and augmented reality games on vision-based wearable device, a touch-less motion interaction technology is designed and evaluated in this work. Users interact with the augmented reality games with dynamic hands/feet gestures in front of the camera, which triggers the interaction event to interact with the virtual object in the scene. Three primitive augmented reality games with eleven dynamic gestures are developed based on the proposed touch-less interaction technology as proof. At last, a comparing evaluation is proposed to demonstrate the social acceptability and usability of the touch-less approach, running on a hybrid wearable framework or with Google Glass, as well as workload assessment, user's emotions and satisfaction.

Preprint Touch-less Interactive Augmented Reality Game on Vision Based Wearable Device

Business process modeling plays an important role in the management of business processes. As valuable design artifacts, business process models are subject to quality considerations. In this context, the absence of formal errors, such as deadlocks, is of paramount importance for the subsequent implementation of the process. This talk presents the results of my doctoral thesis that provides a fourfold contribution to the understanding of such errors in business process models with a particular focus on Event-driven Process Chains (EPCs), a business process modeling language that is frequently used in practice. Firstly, I formalize the operational semantics of EPCs in a novel way so that matching OR-splits and OR-joins never deadlock. Secondly, and based on these semantics, we introduce a soundness criterion for EPCs that offers a precise identification of those models which have errors. For the verification of this soundness notion in practice, I present two analysis tools, a ProM plug-in for a verification based on the reachability graph, and a batch program called xoEPC for a verification based on reduction rules. Thirdly, I define a set of business process model metrics that are supposed to serve as predictors for error probability of an individual EPC. Fourthly, I use statistical methods and a sample of about 2000 EPCs from practice to derive a regression function for the prediction of error probability. This function is validated against a holdout set of 113 EPCs from textbooks showing that 90% of the EPCs could be classified correctly as having errors or not. These results emphasize the importance of quality issues in business process modeling, and provides the foundations for innovations in tool support.

On the Detection and Prediction of Errors in EPC Business Process Models.

Query processing in mobile database systems is a special challenge because we have to consider the limited resources of mobile systems as well as the changing location of mobile users. In this paper, we concentrate on the optimisation of queries including location information. We present a cost model for query optimisation incorporating mobility specific factors like energy and connectivity. Furthermore, we examine different localisation strategies for mobile users. This innovative connection of both factors is studied using two typical classes of queries. Using a newly developed simulation model, we describe that no single localisation strategy performs acceptable under every condition. We therefore identify the critical factors for adapting a query processing subsystem to the employed location management strategy. 1 I n t r o d u c t i o n The development of wireless communication systems and lightweight computers has led to the availability of a research area called mobile computing. The subject of research is the effect of mobility on systems, users, data and computing. In the area of database systems, mobility offers access to information anywhere and anytime. In order to access information, we have to consider the query processing in mobile database systems as one major task. Queries in mobile systems are different from stationary systems. There, location awareness adds power to the mobile user but also adds complexity to the query processPermission to make digital/hard copy of all or part of this work for personal or classroom use is granted without l~e provided that copies are not made or distributed lbr profit or commercial advantage, the copyright notice, the title of the publication and its date appear, and notice is given that copying is by permission of ACM. Inc. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. ,: 1q98 ACM 0-89791-969-6/98/0002 3.50 ing. Examples of location aware queries in mobile database systems are traffic information systems that give the user information with respect to his current location ("where is the next pub serving Becks beer") or queries retrieving data from mobile users whose location needs to be looked up. Apart from this new kind of queries, mobile systems pose even more new requirements on the query processing subsystem of a mobile database because of the limited resources available on typical mobile computers. Therefore, query subsystems of mobile databases have to be modified compared to stationary query processors [4]. Additionally, location information about mobile users must be categorised as only temporarily valid since mobile users may move and data on their actual location has to be updated in order to address them properly. The location management component is responsible for the storage of current location information. Ad hoc queries that use location information about mobile users have to access the location management component. Depending on the used localisation strategy, we have different costs associated with processing this kind of query. Therefore, an optimal query processing subsystem of a mobile database has to take the strategy used by the location management component into account for answering queries. In this paper, we present a new approach to the integration of these two components. We pay special attention to the usage of fuzzy information as provided by many real-world location management components. Starting by an introduction to existing location management and mobile query processing strategies in the next section, we afterwards present a new abstract model for representing mobile systems and location management components. In section four, we discuss our approach to location aware query optimisation in mobile database systems. For this, we have developed a mobility aware cost model for processing location dependent queries. To validate the model,

Location-aware query processing in mobile database systems

Workflow management systems are used to support the computer based execution of processes in an enterprise. They require a description of these processes as well as an engine that implements the execution environment. Currently, workflow management systems have to introduce some new languages for the description of workflows in order to allow an execution of processes.

From Business Process Modelling to Workflow Management: An Integrated Approach

In this paper, we describe the design and realization of FRAP, a framework for the construction of pervasive games. With FRAP, we focus on context-aware multi-user chase games that include a strategic component. The game domain is exemplified by the "capture the flag" metaphor. The playing field supported by our framework is a combined virtual and physical world in which the player socially interacts with other players. FRAP provides components for typical tasks like players moving in the world solving challenges, updating the score based on the context of the users, and checking the rules of the game. FRAP is fully implemented on the open handset-platform a.k.a. Google Android. Based on FRAP, a pervasive game called "King of Location" has been constructed using the Android-platform. Through this application, a first evaluation of FRAP has been performed. It shows a significant reduction of time to build a game that follows the "capture the flag" metaphor.

FRAP: a framework for pervasive games

Graph processing has achieved a lot of attention in differentbig data scenarios. In this paper, we present the design, implementation, and experimental evaluation of graph processing algorithmsin two differentapplication areas. First, we use semi-clustering as an example of an algorithmtypically used social network analysis. Then, we examine an algorithm for collaborative filteringas typically used in E-Commerce scenarios. For both algorithms, we make use of Apache GraphX as an existing distributedgraph processing framework based on Apache Spark. As GraphX does not include these two algorithms, we describe how to implement them using a combination of GraphX andthe underlying Spark Core. Based on our implementation, we perform experiments to test the scalability of both the algorithmsand the GraphX processing framework. The experiments show that different kinds of graphalgorithms can be supported within the Spark framework. Furthermore, we show that for our test data the algorithmsscale almost linearly when properly designed.

Evaluating the Scaling of Graph-Algorithms for Big Data Using GraphX

Workflow management systems schedule tasks in accordance with previously known process types. Additionally, advanced workflow applications have to deal with parametric processes and exceptional situations. Using active database technology to implement such applications results in mature demands for their respective time handling capabilities. This regards both, the possibilities of time specification as well as a sophisticated time management within the rule execution mechanism.

Olaf Zukunft

Papers

Location-aware query processing in mobile database systems

From Business Process Modelling to Workflow Management: An Integrated Approach

FRAP: a framework for pervasive games

Evaluating the Scaling of Graph-Algorithms for Big Data Using GraphX

Time Issues in Advanced Workflow Management Applications of Active Databases