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Integrated Mobile Visualization and Interaction of Events and POIs (2010)
Schmeiß, Daniel ; Scherp, Ansgar ; Staab, Steffen
We propose a new approach for mobile visualization and interaction of temporal information by integrating support for time with today's most prevalent visualization of spatial information, the map. Our approach allows for an easy and precise selection of the time that is of interest and provides immediate feedback to the users when interacting with it. It has been developed in an evolutionary process gaining formative feedback from end users.
Designing Core Ontologies (2011)
Scherp, Ansgar ; Saathoff, Carsten ; Franz, Thomas ; Staab, Steffen
One of the key factors that hinders integration of distributed, heterogeneous information systems is the lack of a formal basis for modeling the complex, structured knowledge that is to be exchanged. To alleviate this situation, we present an approach based on core ontologies. Core ontologies are characterized by a high degree of axiomatization and formal precision. This is achieved by basing on a foundational ontology. In addition, core ontologies should follow a pattern-oriented design approach. By this, they are modular and extensible. Core ontologies allow for reusing the structured knowledge they define as well as integrating existing domainrnknowledge. The structured knowledge of the core ontologies is clearly separated from the domain-specific knowledge. Such core ontologies allow for both formally conceptualize their particular fields and to be flexibly combined to cover the needsrnof concrete, complex application domains. Over the last years, we have developed three independent core ontologies for events and objects, multimedia annotations, and personal information management. In this paper, we present the simultaneousrnuse and integration of our core ontologies at the example of a complex, distributed socio-technical system of emergency response. We describe our design approach for core ontologies and discuss the lessons learned in designing them. Finally, we elaborate on the beauty aspects of our core ontologies.
Explicit and Implicit Schema Information on the Linked Open Data Cloud: Joined Forces or Antagonists? (2012)
Scherp, Ansgar ; Gottron, Thomas ; Knauf, Malte ; Scheglmann, Stefan
Schema information about resources in the Linked Open Data (LOD) cloud can be provided in a twofold way: it can be explicitly defined by attaching RDF types to the resources. Or it is provided implicitly via the definition of the resources´ properties. In this paper, we analyze the correlation between the two sources of schema information. To this end, we have extracted schema information regarding the types and properties defined in two datasets of different size. One dataset is a LOD crawl from TimBL- FOAF profile (11 Mio. triple) and the second is an extract from the Billion Triples Challenge 2011 dataset (500 Mio. triple). We have conducted an in depth analysis and have computed various entropy measures as well as the mutual information encoded in this two manifestations of schema information. Our analysis provides insights into the information encoded in the different schema characteristics. It shows that a schema based on either types or properties alone will capture only about 75% of the information contained in the data. From these observations, we derive conclusions about the design of future schemas for LOD.
A model of events based on a foundational ontology (2009)
Scherp, Ansgar ; Franz, Thomas ; Saathoff, Carsten ; Staab, Steffen
The lack of a formal event model hinders interoperability in distributed event-based systems. Consequently, we present in this paper a formal model of events, called F. The model bases on an upper-level ontology and pro-vides comprehensive support for all aspects of events such as time and space, objects and persons involved, as well as the structural aspects, namely mereological, causal, and correlational relationships. The event model provides a flexible means for event composition, modeling of event causality and correlation, and allows for representing different interpretations of the same event. The foundational event model F is developed in a pattern-oriented approach, modularized in different ontologies, and can be easily extended by domain specifific ontologies.
Integrating Multimedia Metadata Standarts and Metadata Formats with the Multimedia Metadata Ontology: Method and Examples (2012)
Scherp, Ansgar ; Eißing, Daniel ; Saathoff, Carsten
The Multimedia Metadata Ontology (M3O) provides a generic modeling framework for representing multimedia metadata. It has been designed based on an analysis of existing metadata standards and metadata formats. The M3O abstracts from the existing metadata standards and formats and provides generic modeling solutions for annotations, decompositions, and provenance of metadata. Being a generic modeling framework, the M3O aims at integrating the existing metadata standards and metadata formats rather than replacing them. This is in particular useful as today's multimedia applications often need to combine and use more than one existing metadata standard or metadata format at the same time. However, applying and specializing the abstract and powerful M3O modeling framework in concrete application domains and integrating it with existing metadata formats and metadata standards is not always straightforward. Thus, we have developed a step-by-step alignment method that describes how to integrate existing multimedia metadata standards and metadata formats with the M3O in order to use them in a concrete application. We demonstrate our alignment method by integrating seven different existing metadata standards and metadata formats with the M3O and describe the experiences made during the integration process.
Networked RDF graphs (2007)
Schenk, Simon ; Staab, Steffen
Networked graphs are defined in this paper as a small syntactic extension of named graphs in RDF. They allow for the definition of a graph by explicitly listing triples as well as by SPARQL queries on one or multiple other graphs. By this extension it becomes possible to define a graph including a view onto other graphs and to define the meaning of a set of graphs by the way they reference each other. The semantics of networked graphs is defined by their mapping into logic programs. The expressiveness and computational complexity of networked graphs, varying by the set of constraints imposed on the underlying SPARQL queries, is investigated. We demonstrate the capabilities of networked graphs by a simple use case.
Model-driven Generation of APIs for OWL-based Ontologies (2010)
Scheglmann, Stefan ; Scherp, Ansgar ; Staab, Steffen
Existing tools for generating application programming interfaces (APIs) for ontologies lack sophisticated support for mapping the logics-based concepts of the ontology to an appropriate object-oriented implementation of the API. Such a mapping has to overcome the fundamental differences between the semantics described in the ontology and the pragmatics, i.e., structure, functionalities, and behavior implemented in the API. Typically, concepts from the ontology are mapped one-to-one to classes in the targeted programming language. Such a mapping only produces concept representations but not an API at the desired level of granularity expected by an application developer. We present a Model-Driven Engineering (MDE) process to generate customized APIs for ontologies. This API generation is based on the semantics defined in the ontology but also leverages additional information the ontology provides. This can be the inheritance structure of the ontology concepts, the scope of relevance of an ontology concept, or design patterns defined in the ontology.
Extended Description of the Survey on Common Strategies of Vocabulary Reuse in Linked Open Data Modeling (2014)
Schaible, Johann ; Gottron, Thomas ; Scherp, Ansgar
Modeling and publishing Linked Open Data (LOD) involves the choice of which vocabulary to use. This choice is far from trivial and poses a challenge to a Linked Data engineer. It covers the search for appropriate vocabulary terms, making decisions regarding the number of vocabularies to consider in the design process, as well as the way of selecting and combining vocabularies. Until today, there is no study that investigates the different strategies of reusing vocabularies for LOD modeling and publishing. In this paper, we present the results of a survey with 79 participants that examines the most preferred vocabulary reuse strategies of LOD modeling. Participants of our survey are LOD publishers and practitioners. Their task was to assess different vocabulary reuse strategies and explain their ranking decision. We found significant differences between the modeling strategies that range from reusing popular vocabularies, minimizing the number of vocabularies, and staying within one domain vocabulary. A very interesting insight is that the popularity in the meaning of how frequent a vocabulary is used in a data source is more important than how often individual classes and properties arernused in the LOD cloud. Overall, the results of this survey help in understanding the strategies how data engineers reuse vocabularies, and theyrnmay also be used to develop future vocabulary engineering tools.
Social networking platforms as creativity fostering systems: research model and exploratory study (2008)
Schaarschmidt, Mario ; Korflesch, Harald F. O. von
Social networking platforms are enabling users to create their own content, share this content with anyone they invite and organize connections with existing or new online contacts. Within these electronic environments users voluntarily add comments on virtual boards, distribute their search results or add information about their expertise areas to their social networking profiles and thereby share it with acquaintances, friends and increasingly even with colleagues in the corporate world. As a result, it is most likely that the underlying knowledge sharing processes result in many new and creative ideas. The objective of our research therefore is to understand if and how social social networking platforms can enforce creativity. In addition, we look at how these processes could be embedded within the organizational structures that influence innovative knowledge sharing behavior. The basis for our research is a framework which focuses on the relations between intrinsic motivation, creativity and social networking platforms. First results of our empirical investigation of a social software platform called "StudiVZ.net" proved that our two propositions are valid.
Crowdsourcing for Survey Research : where Amazon Mechanical Turks deviates from conventional survey methods (2015)
Schaarschmidt, Mario ; Ivens, Stefan ; Homscheid, Dirk ; Bilo, Pascal
Information systems research has started to use crowdsourcing platforms such as Amazon Mechanical Turks (MTurk) for scientific research, recently. In particular, MTurk provides a scalable, cheap work-force that can also be used as a pool of potential respondents for online survey research. In light of the increasing use of crowdsourcing platforms for survey research, the authors aim to contribute to the understanding of its appropriate usage. Therefore, they assess if samples drawn from MTurk deviate from those drawn via conventional online surveys (COS) in terms of answers in relation to relevant e-commerce variables and test the data in a nomological network for assessing differences in effects. The authors compare responses from 138 MTurk workers with those of 150 German shoppers recruited via COS. The findings indicate, inter alia, that MTurk workers tend to exhibit more positive word-of mouth, perceived risk, customer orientation and commitment to the focal company. The authors discuss the study- results, point to limitations, and provide avenues for further research.
Methods for Human-Machine Link Quality Management on the Web of Data (2022)
Sarasua, Cristina
Semantic Web technologies have been recognized to be key for the integration of distributed and heterogeneous data sources on the Web, as they provide means to define typed links between resources in a dynamic manner and following the principles of dataspaces. The widespread adoption of these technologies in the last years led to a large volume and variety of data sets published as machine-readable RDF data, that once linked constitute the so-called Web of Data. Given the large scale of the data, these links are typically generated by computational methods that given a set of RDF data sets, analyze their content and identify the entities and schema elements that should be connected via the links. Analogously to any other kind of data, in order to be truly useful and ready to be consumed, links need to comply with the criteria of high quality data (e.g., syntactically and semantically accurate, consistent, up-to-date). Despite the progress in the field of machine learning, human intelligence is still essential in the quest for high quality links: humans can train algorithms by labeling reference examples, validate the output of algorithms to verify their performance on a data set basis, as well as augment the resulting set of links. Humans —especially expert humans, however, have limited availability. Hence, extending data quality management processes from data owners/publishers to a broader audience can significantly improve the data quality management life cycle. Recent advances in human computation and peer-production technologies opened new avenues for human-machine data management techniques, allowing to involve non-experts in certain tasks and providing methods for cooperative approaches. The research work presented in this thesis takes advantage of such technologies and investigates human-machine methods that aim at facilitating link quality management in the Semantic Web. Firstly, and focusing on the dimension of link accuracy, a method for crowdsourcing ontology alignment is presented. This method, also applicable to entities, is implemented as a complement to automatic ontology alignment algorithms. Secondly, novel measures for the dimension of information gain facilitated by the links are introduced. These entropy-centric measures provide data managers with information about the extent the entities in the linked data set gain information in terms of entity description, connectivity and schema heterogeneity. Thirdly, taking Wikidata —the most successful case of a linked data set curated, linked and maintained by a community of humans and bots— as a case study, we apply descriptive and predictive data mining techniques to study participation inequality and user attrition. Our findings and method can help community managers make decisions on when/how to intervene with user retention plans. Lastly, an ontology to model the history of crowd contributions across marketplaces is presented. While the field of human-machine data management poses complex social and technical challenges, the work in this thesis aims to contribute to the development of this still emerging field.
MapReduce with Deltas (2011)
Saile, David
The MapReduce programming model is extended slightly in order to use deltas. Because many MapReduce jobs are being re-executed over slightly changing input, processing only those changes promises significant improvements. Reduced execution time allows for more frequent execution of tasks, yielding more up-to-date results in practical applications. In the context of compound MapReduce jobs, benefits even add up over the individual jobs, as each job gains from processing less input data. The individual steps necessary in working with deltas are being analyzed and examined for efficiency. Several use cases have been implemented and tested on top of Hadoop. The correctness of the extended programming model relies on a simple correctness criterion.
Visual Teaching in Image Based Classification Problems (2008)
Röttger, Diana
PAPEL: Syntax and Semantics for Provenance-Aware Policy Definition (2010)
Ringelstein, Christoph ; Staab, Steffen
The processing of data is often restricted by contractual and legal requirements for protecting privacy and IPRs. Policies provide means to control how and by whom data is processed. Conditions of policies may depend on the previous processing of the data. However, existing policy languages do not provide means to express such conditions. In this work we present a formal model and language allowing for specifying conditions based on the history of data processing. We base the model and language on XACML.
Combined Non-Linear Pose Estimation from Points and Lines (2011)
Reinert, Bernhard ; Schumann, Martin ; Müller, Stefan
We present a non-linear camera pose estimator, which is able to handle a combined input of point and line feature correspondences. For three or more correspondences, the estimator works on any arbitrary number and choice of the feature type, which provides an estimation of the pose on a preferably small and flexible amount of 2D-3D correspondences. We also give an analysis of different minimization techniques, parametrizations of the pose data, and of error measurements between 2D and 3D data. These will be tested for the usage of point features, lines and the combination case. The result shows the most stable and fast working non-linear parameter set for pose estimation in model-based tracking.
Finite automata on unranked and unordered DAGs (2007)
Priese, Lutz
We introduce linear expressions for unrestricted dags (directed acyclic graphs) and finite deterministic and nondeterministic automata operating on them. Those dag automata are a conservative extension of the Tu,u-automata of Courcelle on unranked, unordered trees and forests. Several examples of dag languages acceptable and not acceptable by dag automata and some closure properties are given.
Design Patterns for API Analysis & Migration (2012)
Pehl, Joachim
Software projects typically rely on several, external libraries. The interface provided by such a library is called API (application programming interface). APIs often evolve over time, thereby implying the need to adapt applications that use them. There are also reasons which may call for the replacement of one library by another one, what also results in a need to adapt the applications where the library is replaced. The process of adapting applications to use a different API is called API migration. Doing API migration manually is a cumbersome task. Automated API migration is an active research field. A related field of research is API analysis which can also provide data for developing API migration tools. The following thesis investigates techniques and technologies for API analysis and API migration frameworks. To this end, design patterns are leveraged. These patterns are based on experience with API analysis and migration within the Software Languages Team.
Improvements of a First Aid Application Based on a Usability Study (2013)
Paschke, Janine Denise
This paper consists of the observation of existing first aid applications for smartphones and comparing them to a first aid application developed by the University of Koblenz called "Defi Now!". The main focus lies on examining "Defi Now!" in respect to its usability based on the dialogue principles referring to the seven software ergonomic principles due to the ISO 9241-110 standard. These are known as suitability for learning, controllability, error tolerance, self-descriptiveness, conformity with user expectations, suitability for the task, and suitability for individualization. Therefore a usability study was conducted with 74 participants. A questionnaire was developed, which was to be filled out by the test participants anonymously. The test results were used for an optimization of the app referring its' usability.
TwoUse: Integrating UML models and OWL ontologies (2007)
Parreiras, Fernando Silva ; Staab, Steffen ; Winter, Andreas
UML models and OWL ontologies constitute modeling approaches with different strength and weaknesses that make them appropriate for use of specifying different aspects of software systems. In particular, OWL ontologies are well suited to specify classes using an expressive logical language with highly flexible, dynamic and polymorphic class membership, while UML diagrams are much more suitable for specifying not only static models including classes and associations, but also dynamic behavior. Though MOF based metamodels and UML profiles for OWL have been proposed in the past, an integrated use of both modeling approaches in a coherent framework has been lacking so far. We present such a framework, TwoUse, for developing integrated models, comprising the benefits of UML models and OWL ontologies
A Full 2D/3D GraphSLAM System for Globally Consistent Mapping based on Manifolds (2012)
Neuhaus, Frank
Robotics research today is primarily about enabling autonomous, mobile robots to seamlessly interact with arbitrary, previously unknown environments. One of the most basic problems to be solved in this context is the question of where the robot is, and what the world around it, and in previously visited places looks like " the so-called simultaneous localization and mapping (SLAM) problem. We present a GraphSLAM system, which is a graph-based approach to this problem. This system consists of a frontend and a backend: The frontend- task is to incrementally construct a graph from the sensor data that models the spatial relationship between measurements. These measurements may be contradicting and therefore the graph is inconsistent in general. The backend is responsible for optimizing this graph, i. e. finding a configuration of the nodes that is least contradicting. The nodes represent poses, which do not form a regular vector space due to the contained rotations. We respect this fact by treating them as what they really are mathematically: manifolds. This leads to a very efficient and elegant optimization algorithm.
Generic task planning using semantic annotations in maps (2012)
Navarro Luzón, Carmen
The purpose of this master thesis is to enable the Robot Lisa to process complex commands and extract the necessary information in order to perform a complex task as a sequence of smaller tasks. This is intended to be achieved by the improvement of the understanding that Lisa has of her environment by adding semantics to the maps that she builds. The complex command itself will be expected to be already parsed. Therefore the way the input is processed to become a parsed command is out of the scope of this work. Maps that Lisa builds will be improved by the addition of semantic annotations that can include any kind of information that might be useful for the performance of generic tasks. This can include (but not necessarily limited to) hierarchical classifications of locations, objects and surfaces. The processing of the command in addition to some information of the environment shall trigger the performance of a sequence of actions. These actions are expected to be included in Lisa- currently implemented tasks and will rely on the currently existing modules that perform them. Nevertheless the aim of this work is not only to be able to use currently implemented tasks in a more complex sequence of actions but also make it easier to add new tasks to the complex commands that Lisa can perform.
Using Constraint Logic Programming for Modeling and Verifying Hierarchical Hybrid Automata (2009)
Mohammed, Ammar ; Stolzenburg, Frieder
Hybrid systems are the result of merging the two most commonly used models for dynamical systems, namely continuous dynamical systems defined by differential equations and discrete-event systems defined by automata. One can view hybrid systems as constrained systems, where the constraints describe the possible process flows, invariants within states, and transitions on the one hand, and to characterize certain parts of the state space (e.g. the set of initial states, or the set of unsafe states) on the other hand. Therefore, it is advantageous to use constraint logic programming (CLP) as an approach to model hybrid systems. In this paper, we provide CLP implementations, that model hybrid systems comprising several concurrent hybrid automata, whose size is only straight proportional to the size of the given system description. Furthermore, we allow different levels of abstraction by making use of hierarchies as in UML statecharts. In consequence, the CLP model can be used for analyzing and testing the absence or existence of (un)wanted behaviors in hybrid systems. Thus in summary, we get a procedure for the formal verification of hybrid systems by model checking, employing logic programming with constraints.
Multi-agent systems: modeling and verification using hybrid automata (2010)
Mohammed, Ammar ; Furbach, Ulrich
Hybrid automata are used as standard means for the specification and analysis of dynamical systems. Several researches have approached them to formally specify reactive Multi-agent systems situated in a physical environment, where the agents react continuously to their environment. The specified systems, in turn, are formally checked with the help of existing hybrid automata verification tools. However, when dealing with multi-agent systems, two problems may be raised. The first problem is a state space problem raised due to the composition process, where the agents have to be parallel composed into an agent capturing all possible behaviors of the multi-agent system prior to the verification phase. The second problem concerns the expressiveness of verification tools when modeling and verifying certain behaviors. Therefore, this paper tackles these problems by showing how multi-agent systems, specified as hybrid automata, can be modeled and verified using constraint logic programming(CLP). In particular, a CLP framework is presented to show how the composition of multi-agent behaviors can be captured dynamically during the verification phase. This can relieve the state space complexity that may occur as a result of the composition process. Additionally, the expressiveness of the CLP model flexibly allows not only to model multi-agent systems, but also to check various properties by means of the reachability analysis. Experiments are promising to show the feasibility of our approach.
RoboCup 2017 – homer@UniKoblenz (Germany) (2018)
Memmesheimer, Raphael
This paper describes the robot Lisa used by team homer@UniKoblenz of the University of Koblenz Landau, Germany, for the participation at the RoboCup@Home 2017 in Nagoya, Japan. A special focus is put on novel system components and the open source contributions of our team. We have released packages for object recognition, a robot face including speech synthesis, mapping and navigation, speech recognition interface via android and a GUI. The packages are available (and new packages will be released) on http://wiki.ros.org/agas-ros-pkg.
RoboCup 2016 – homer@UniKoblenz (Germany) (2018)
Memmesheimer, Raphael
This paper describes the robot Lisa used by team homer@UniKoblenz of the University of Koblenz Landau, Germany, for the participation at the RoboCup@Home 2016 in Leipzig, Germany. A special focus is put on novel system components and the open source contributions of our team. We have released packages for object recognition, a robot face including speech synthesis, mapping and navigation, speech recognition interface via android and a GUI. The packages are available (and new packages will be released) on http://wiki.ros.org/agas-ros-pkg.
CAMPUS NEWS - artificial intelligence methods combined for an intelligent information network (2008)
Maron, Markus ; Read, Kevin ; Schulze, Michael
In this paper we describe a network for distributing personalised information with the usage of artificial intelligence methods. Reception of this information should be possible with everyday mobile equipment. Intelligent filtering and spam protection aim at integrating this technology into our environment. Information on the system architecture and usage of the installation are also presented.
An empirical study to evaluate the location of advertisement panels by using a mobile marketing tool (2009)
Magnus, Sebastian ; Maron, Markus
The efficiency of marketing campaigns is a precondition for business success. This paper discusses a technique to transfer advertisement content vie Bluetooth technology and collects market research information at the same time. Conventional advertisement media were enhanced by devices to automatically measure the number, distance, frequency and exposure time of passersby, making information available to evaluate both the wireless media as well as the location in general. This paper presents a study analyzing these data. A cryptographic one-way function protects privacy during data acquisition.
A public key infrastructure in ambient information and transaction systems (2010)
Magnus, Sebastian ; Maron, Markus
Conventional security infrastructures in the Internet cannot be directly adopted to ambient systems, especially if based on short-range communication channels: Personal, mobile devices are used and the participants are present during communication, so privacy protection is a crucial issue. As ambient systems cannot rely on an uninterrupted connection to a Trust Center, certiffed data has to be veriffed locally. Security techniques have to be adjusted to the special environment. This paper introduces a public key infrastructure (PKI) to provide secure communication channels with respect to privacy, confidentiality, data integrity, non-repudiability, and user or device authentication. It supports three certiffcate levels with a different balance between authenticity and anonymity. This PKI is currently under implementation as part of the iCity project.
Security in Distance Vector Algorithms (2011)
Lück, Stefanie
Distance vector routing protocols are interior gateway protocols in which every router sets up a routing table with the help of the information it receives from its neighboring routers. The routing table contains the next hops and associated distances on the shortest paths to every other router in the network. Security mechanisms implemented in distance vector routing protocols are insufficient. It is rather assumed that the environment is trustworthy. However, routers can be malicious for several reasons and manipulate routing by injecting false routing updates. Authenticity and integrity of transmitted routing updates have to be guaranteed and at the same time performance and benefits should be well-balanced. In this paper several approaches that aim at meeting the above mentioned conditions are examined and their advantages and disadvantages are compared.
Probability Propagation Nets and Duality (2012)
Lautenbach, Kurt ; Susewind, Kerstin
The paper deals with a specific introduction into probability propagation nets. Starting from dependency nets (which in a way can be considered the maximum information which follows from the directed graph structure of Bayesian networks), the probability propagation nets are constructed by joining a dependency net and (a slightly adapted version of) its dual net. Probability propagation nets are the Petri net version of Bayesian networks. In contrast to Bayesian networks, Petri nets are transparent and easy to operate. The high degree of transparency is due to the fact that every state in a process is visible as a marking of the Petri net. The convenient operability consists in the fact that there is no algorithm apart from the firing rule of Petri net transitions. Besides the structural importance of the Petri net duality there is a semantic matter; common sense in the form of probabilities and evidencebased likelihoods are dual to each other.
Applying Probability Propagation Nets (2012)
Lautenbach, Kurt ; Susewind, Kerstin
In this paper, we demonstrate by means of two examples how to work with probability propagation nets (PPNs). The fiirst, which comes from the book by Peng and Reggia [1], is a small example of medical diagnosis. The second one comes from [2]. It is an example of operational risk and is to show how the evidence flow in PPNs gives hints to reduce high losses. In terms of Bayesian networks, both examples contain cycles which are resolved by the conditioning technique [3].
Probability propagation nets (2007)
Lautenbach, Kurt ; Pinl, Alexander
A class of high level Petri nets, called "probability propagation nets", is introduced which is particularly useful for modeling probability and evidence propagation. These nets themselves are well suited to represent the probabilistic Horn abduction, whereas specific foldings of them will be used for representing the flows of probabilities and likelihoods in Bayesian networks.
The Quaternality of Simulation: An Event/Non-Event Approach (2012)
Lautenbach, Kurt
Dualizing marked Petri nets results in tokens for transitions (t-tokens). A marked transition can strictly not be enabled, even if there are sufficient "enabling" tokens (p-tokens) on its input places. On the other hand, t-tokens can be moved by the firing of places. This permits flows of t-tokens which describe sequences of non-events. Their benefiit to simulation is the possibility to model (and observe) causes and effects of non-events, e.g. if something is broken down.
A Petri net approach for propagating probabilities and mass functions (2010)
Lautenbach, Kurt
This paper has a twofold concern. First, to show that probability propagation nets (PPNs) can be derived from formulae for conditional probabilities. Second, to show that PPNs are usable for (local) propagations of mass distributions, too, if the inscriptions are suitably adapted.
Requirements for Health Care Related Websites in Russia: results from an Analysis of American British and German Examples (2011)
Lantsberg, Anna ; Troitzsch, Klaus G.
The paper is devoted to solving a problem of the development of the website of Russian municipal policlinics and provides a selection of a set of elements which should be posted on a website. Such elements are necessary to provide citizens with correct and ergonomic e-services. The insufficient development of an infrastructure of institutions of public and municipal administration (particularly, healthcare institutions) in Russia made it necessary to analyze webresources used in different countries at different levels of providing medical services. The information resources of medical treatment facilities of the United Kingdom, of the United Statesrnof America and of the Federal Republic of Germany were researched separately for three existing economic models of healthcare. A set of criteria for the assessment of medical webresources was developed.
Distributed Natural Language Search Using Graph-Based Parsing (2013)
Kurz, Nadine Sina
We present the conceptual and technological foundations of a distributed natural language interface employing a graph-based parsing approach. The parsing model developed in this thesis generates a semantic representation of a natural language query in a 3-staged, transition-based process using probabilistic patterns. The semantic representation of a natural language query is modeled in terms of a graph, which represents entities as nodes connected by edges representing relations between entities. The presented system architecture provides the concept of a natural language interface that is both independent in terms of the included vocabularies for parsing the syntax and semantics of the input query, as well as the knowledge sources that are consulted for retrieving search results. This functionality is achieved by modularizing the system's components, addressing external data sources by flexible modules which can be modified at runtime. We evaluate the system's performance by testing the accuracy of the syntactic parser, the precision of the retrieved search results as well as the speed of the prototype.
Simulating medical objects simulation using an artificial neural network whose structure is based on adaptive resonance theory (2011)
Kryuchin, Oleg V. ; Arzamastsev, Alexander A. ; Zenkova, Natalia ; Troitzsch, Klaus G. ; Sletkov, Denis V.
This paper describes artificial neural networks which are based on the adaptive resonance theory. The usage of these artificial neural networks for classification tasks is presented. The example uses is the classification of patient health from the results of general blood analysis.
Simulating social objects with an artificial neural network using a computer cluster (2011)
Kryuchin, Oleg V. ; Arzamastsev, Alexander A. ; Troitzsch, Klaus G. ; Zenkova, Natalia
This paper describes results of the simulation of social objects, the dependence of schoolchildren's professional abilities on their personal characteristics. The simulation tool is the artificial neural network (ANN) technology. Results of a comparison of the time expense for training the ANN and for calculating the weight coefficients with serial and parallel algorithms, respectively, are presented.
The prediction of currency exchange rates using artificial neural networks (2011)
Kryuchin, Oleg V. ; Arzamastsev, Alexander A. ; Troitzsch, Klaus G.
This paper describes the analysis of a neural network used to predict currency exchange rates in comparison to technical analysis. The neural network structures used are a multilayer perceptron and a Volterra network.
A universal simulator based on artificial neural networks for computer clusters (2011)
Kryuchin, Oleg V. ; Arzamastsev, Alexander A. ; Troitzsch, Klaus G.
This paper describes parallel algorithms for training artifcial neural networks. Possible levels of parallelity are presented. Experiments for checking the effciency of algorithms are discussed.
Comparing the efficiency of serial and parallel algorithms for training artificial neural networks using computer clusters (2011)
Kryuchin, Oleg V. ; Arzamastsev, Alexander A. ; Troitzsch, Klaus G.
An estimation of the number of multiplication and addition operations for training artififfcial neural networks by means of consecutive and parallel algorithms on a computer cluster is carried out. The evaluation of the efficiency of these algorithms is developed. The multilayer perceptron, the Volterra network and the cascade-correlation network are used as structures of artififfcial neural networks. Different methods of non-linear programming such as gradient and non-gradient methods are used for the calculation of the weight coefficients.
Concept Network Extraction from Text (2013)
Krukow, Oliver
Large amounts of qualitative data make the utilization of computer-assisted methods for their analysis inevitable. In this thesis Text Mining as an interdisciplinary approach, as well as the methods established in the empirical social sciences for analyzing written utterances are introduced. On this basis a process of extracting concept networks from texts is outlined and the possibilities of utilitzing natural language processing methods within are highlighted. The core of this process is text processing, to whose execution software solutions supporting manual as well as automated work are necessary. The requirements to be met by these solutions, against the background of the initiating project GLODERS, which is devoted to investigating extortion racket systems as part of the global fiσnancial system, are presented, and their fulσlment by the two most preeminent candidates reviewed. The gap between theory and pratical application is closed by a prototypical application of the method to a data set of the research project utilizing the two given software solutions.
Which work-life balance offers should companies prowide nowadays? (2016)
Krath, Jeanine ; Zerwas, Claire ; Korflesch, Harald F. O. von
In order to enhance the company’s appeal for potential employees and improve the satisfaction of already salaried workers, it is necessary to offer a variety of work-life balance measures. But as their implementation causes time and financial costs, a prioritization of measures is needed. To express a recommendation for companies, this study is led by the questions if there are work-life balance measures which have more impact on employee satisfaction than others, how big the relative impact of work-life balance measures on job satisfaction in comparison to other work and private life variables is, if there is a relation between the effectiveness of measures and their use and if there is a difference between the measures which are most important from the employees’ perspective and the companies’ offers. These questions are formulated in eight research hypotheses which are examined in a quantitative research design with online survey data from 289 employees of fifteen different German companies. The formation of a hierarchy of the effectiveness of measures towards job satisfaction as well as the investigation of the relative impact in comparison to other variables is performed using a multiple regression analysis, whilst the differences between employees’ expectations and the availability of offers are examined with t-tests. Support in childcare, support in voluntary activities and teambuilding events have a significantly higher impact on job satisfaction than other work-life balance measures, and their potential use is higher than the actual use which leads to the conclusion that there is yet potential for companies to improve their employees’ satisfaction by implementing these measures. In addition, flexible work hours, flexible work locations and free time and overtime accounts are the most important measures from the employees’ point of view and already widely offered by the surveyed companies. In general, the overall use of the available measures and the quantity of offered measures are more important with regard to job satisfaction than the specific kind of measure. In addition, work-life balance measures are more important towards job satisfaction for younger people.
Introducing Entrepeneurial Design Thinking (2012)
Korflesch, Harald F. O. von ; Mokanis, Ilias ; Zerwas, Dorothée
The objective of this contribution is to conceptually analyze the potentials of entrepreneurial design thinking as being a rather new method for entrepreneurship education. Based on a literature review of different design thinking concepts we carve out a generic design thinking model upon we conceptually build a new model that considers entrepreneurial thinking as a valuable characteristic. The results of our work show that the characteristics of entrepreneurial design thinking can enhance entrepreneurship education by supporting respective action fields of entrepreneurial learning. In addition we reveal that entrepreneurial design thinking offers beneficial guidelines for the design of entrepreneurship education programs.
What impedes Consumers’ Delivery Drone Service Adoption? (2020)
Knobloch, Marius ; Schaarschmidt, Mario
Despite widespread plans of big companies like Amazon and Google to develop unmanned delivery drones, scholarly research in this field is scarce, especially in the information systems field. From technical and legal perspectives, drone delivery in last-mile scenarios is in a quite mature state. However, estimates of user acceptance are varying between high skepticism and exaggerated optimism. This research follows a mixed method approach consisting both qualitative and quantitative research, to identify and test determinants of consumer delivery drone service adoption. The qualitative part rests on ten interviews among average consumers, who use delivery services on a regular basis. Insights gained from the qualitative part were used to develop an online survey and to assess the influence of associated risks on adoption intentions. The quantitative results show that especially financial and physical risks impede drone delivery service adoption. Delivery companies who are currently thinking about providing a delivery drone service may find these results useful when evaluating usage behaviors in the future market for delivery drones.
Reproducible Wrapper for API Migration (2011)
Knauf, Malte
API migration refers to the change of a used API to a different API in a program. A special case is called wrapper-based API migration. The API change is done without touching the program but the old API is reimplemented by means of the from now on used one. This so called wrapper has the interface of the reimplemented API but uses the implementation of the new one. This is an interesting approach because the wrapper can be used in each program, which uses the old API. To make this approach reproducible we study a ranking-based method for implementing a wrapper, where we always implement the method with the highest priority depending on failing test cases. Thus, we can reconstruct each implementation step. We first develop an infrastructure to run and log test suites of Java projects that use an API, which we want to change. We then build a wrapper for a given API using the ranking-based approach.
Mobile Facets - faceted search and exploration of open social media data on a touchscreen mobile phone (2011)
Kleinen, Alexander ; Scherp, Ansgar ; Staab, Steffen
We present the user-centered, iterative design of Mobile Facets, a mobile application for the faceted search and exploration of a large, multi-dimensional data set of social media on a touchscreen mobile phone. Mobile Facets provides retrieval of resources such as places, persons, organizations, and events from an integration of different open social media sources and professional content sources, namely Wikipedia, Eventful, Upcoming, geo-located Flickr photos, and GeoNames. The data is queried live from the data sources. Thus, in contrast to other approaches we do not know in advance the number and type of facets and data items the Mobile Facets application receives in a specific contextual situation. While developingrnMobile Facets, we have continuously evaluated it with a small group of fifive users. We have conducted a task-based, formative evaluation of the fifinal prototype with 12 subjects to show the applicability and usability of our approach for faceted search and exploration on a touchscreen mobile phone.
Iterative Signing of RDF(S) Graphs, Named Graphs, and OWL Graphs: Formalization and Application (2013)
Kasten, Andreas ; Scherp, Ansgar
When publishing graph data on the web such as vocabulariesrnusing RDF(S) or OWL, one has only limited means to verify the authenticity and integrity of the graph data. Today's approaches require a high signature overhead and do not allow for an iterative signing of graph data. This paper presents a formally defined framework for signing arbitrary graph data provided in RDF(S), Named Graphs, or OWL. Our framework supports signing graph data at different levels of granularity: minimum self-contained graphs (MSG), sets of MSGs, and entire graphs. It supports for an iterative signing of graph data, e. g., when different parties provide different parts of a common graph, and allows for signing multiple graphs. Both can be done with a constant, low overhead for the signature graph, even when iteratively signing graph data.
Image annotation tool for collecting expert knowledge (2008)
Jeong, Yoo-Jin
VocVille - a casual social game for learning vocabulary (2011)
Jensen, Michel
This paper introduces Vocville, a causal online game for learning vocabularies. I am creating this application for my master thesis of my career as a "Computervisualist" (computer visions) for the University of Koblenz - Landau. The application is an online browser game based on the idea of the really successful Facebook game FarmVille. The application is seperated in two parts; a Grails application manages a database which holds the game objects like vocabulary, a Flex/Flash application generates the actual game by using these data. The user can create his own home with everything in it. For creating things, the user has to give the correct translation of the object he wants to create several times. After every query he has to wait a certain amount of time to be queried again. When the correct answer is given sufficient times, the object is builded. After building one object the user is allowed to build others. After building enough objects in one area (i.e. a room, a street etc.) the user can activate other areas by translating all the vocabularies of the previous area. Users can also interact with other users by adding them as neighbors and then visiting their homes or sending them gifts, for which they have to fill in the correct word in a given sentence.
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