Master's Thesis
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Currently more than 850 biological databases exist. The majority of biological knowledge is not in these databases but rather contained as free text in scientific literature. For systems biology tasks it is often necessary to integrate and extract data from heterogeneous databases and free text as well as to analyse the information in the context of experimental data. ONDEX is an integration framework which aims to address these challenges by combining features of database integration, text mining and sequence analysis with methods for graph-based data analysis and visualisation. The main topics of this diploma thesis are the redesign of the ONDEX backend, the development of a data exchange format, the development of a query environment and the allocation of Web services for data integration, data exchange and queries. These Web services allow backend workflow control from both local and remote workstations.
The thesis develops and evaluates a hypothetical model of the factors that influence user acceptance of weblog technology. Previous acceptance studies are reviewed, and the various models employed are discussed. The eventual model is based on the technology acceptance model (TAM) by Davis et al. It conceptualizes and operationalizes a quantitative survey conducted by means of an online questionnaire, strictly from a user perspective. Finally, it is tested and validated by applying methods of data analysis.
Public electronic procurement (eProcurement), here electronic sourcing (eSourcing) in particular, is almost certainly on the agenda when eGovernment experts meet. Not surprisingly is eProcurement the first high-impact service to be addressed in the European Union- recent Action Plan. This is mainly dedicated to the fact that public procurement makes out almost 20% of Europe- GDP and therefore holds a huge saving potential. To some extent this potential lies in the common European market, since effective cross-boarder eSourcing solutions can open many doors, both for buyers and suppliers. To achieve this, systems and processes and tools, need to be adoptable, transferable as well as be able to communicate with each other. In one word, they need to be interoperable. In many relevant domains, interoperability has reached a very positive level, standards have been established, workflows been put in place. In other domains however, there is still a long road ahead. As a consequence it is crucial to define requirements for such interoperable eSourcing systems and to identify the progress in research and practice.
The internet is becoming more and more important in daily life. Fundamental changes can be observed in the private sector as well as in the public sector. In the course of this, active involvement of citizens in planning political procedures is more and more supported electronically. The expectations culminate in the assumption that information and communication technology (ICT) can enhance civic participation and reduce disenchantment with politics. Out of these expectations, a lot of eparticipation projects were initiated in Germany. Initiatives were established, e.g. the "Initiative eParticipation", which gave many incentives of electronic participation for policy and administration in order to strengthen decision-making processes with internet supported participation practices. This thesis consists of two major parts. In the first part, definitions of the essential terms are presented. The position of e-participation within the dimension of ebusiness is pointed out. In order to explain e-participation, basics of the classical offline participation are delivered. It will be shown that a change is in progress, not only because of the deployment of ICT. Subsequently, a framework to characterize eparticipation is presented. The European Union is encouraging the implementation of e-participation. So, the city of Koblenz should be no exception. But what is the current situation in Koblenz? To provide an answer to this question, the status quo was examined with the help of a survey among the citizens of Koblenz, which was developed, conducted and evaluated. This is the second major part of this thesis.
Entwicklung eines Regelungsverfahrens zur Pfadverfolgung für ein Modellfahrzeug mit Sattelanhänger
(2009)
Besides the progressive automation of internal goods traffic, there is an important area that should also be considered. This area is the carriage of goods in selected external areas. The use of driverless trucks in logistic centers can report economic efficiency. In particular, these precise control procedures require that trucks drive on predetermined paths. The general aim of this work is the adaption and evaluation of a path following control method for articulated vehicles. The differences in the kinematic behavior between trucks with one-axle trailer and semi-trailer vehicles will be emphasized. Additionally, the characteristic kinematic properties of semi-trailers for the adaptation of a control procedure will be considered. This control procedure was initially designed for trucks with one-axle trailer. It must work in forwards and backwards movements. This control process will be integrated as a closed component on the control software of the model vehicle. Thus, the geometry of the model vehicle will be specified, and the possible special cases of the control process will be discovered. The work also documents the most relevant software components of the implemented control process.
The development of a pan-European public E-Procurement system is an important target of the European Union to enhance the efficiency, transparency and competitiveness of public procurement procedures conducted within the European single market. A great obstacle for cross-border electronic procurement is the heterogeneity of national procurement systems in terms of technical, organizational and legal differences. To overcome this obstacle the European Commission funds several initiatives that contribute to the aim of achieving interoperability for pan-European public procurement. Pan European Public Procurement OnLine (PEPPOL) is one of these initiatives that aims at piloting an interoperable pan-European E-Procurement solution to support businesses and public purchasing entities from different member states to conduct their procurement processes electronically.rnrnAs interoperability and inter-connection of distributed heterogeneous information systems are the major requirements in the European procurement domain, and the VCD sub-domain in particular, service-oriented architecture (SOA) seems to provide a promising approach to realize such an architecture, as it promotes loose coupling and interoperability. This master thesis therefore discusses the SOA approach and how its concepts, methodologies and technologies can be used for the development of interoperable IT systems for electronic public procurement. This discussion is enhanced through a practical application of the discussed SOA methodologies by conceptualizing and prototyping of a sub-system derived from the overall system domain of the Virtual Company Dossier. For that purpose, important aspects of interoperability and related standards and technologies will be examined and put into the context of public electronic procurement. Furthermore, the paradigm behind SOA will be discussed, including the derivation of a top-down development methodology for service-oriented systems.
Mobile payment has been a payment option in the market for a long time now and was predicted to become a widely used payment method. However, over the years, the market penetration rate of mPayments has been relatively low, despite it having all characteristics required of a convenient payment method. The primaryrnreason for this has been cited as a lack of customer acceptance mainly caused due to the lack of perceived security by the end-user. Although biometric authentication is not a new technology, it is experiencing a revival in the light of the present day terror threats and increased security requirements in various industries. The application of biometric authentication in mPayments is analysed here and a suitable biometric authentication method for use with mPayments is recommended. The issue of enrolment, human and technical factors to be considered are discussed and the STOF business model is applied to a BiMoP (biometric mPayment) application.
Multi-agent systems are a mature approach to model complex software systems by means of Agent-Oriented Software Engineering (AOSE). However, their application is not widely accepted in mainstream software engineering. Parallel to this the interdisciplinary field of Agent-based Social Simulation (ABSS) finds increasing recognition beyond the purely academic realm which starts to draw attention from the mainstream of agent researchers. This work analyzes factors to improve the uptake of AOSE as well as characteristics which separate the two fields AOSE and ABSS to understand their gap. Based on the efficiency-oriented micro-agent concept of the Otago Agent Platform (OPAL) we have constructed a new modern and self-contained micro-agent platform called µ². The design takes technological trends into account and integrates representative technologies, such as the functionally-inspired JVM language Clojure (with its Transactional Memory), asynchronous message passing frameworks and the mobile application platform Android. The mobile version of the platform shows an innovative approach to allow direct interaction between Android application components and micro-agents by mapping their related internal communication mechanisms. This empowers micro-agents to exploit virtually any capability of mobile devices for intelligent agent-based applications, robotics or simply act as a distributed middleware. Additionally, relevant platform components for the support of social simulations are identified and partially implemented. To show the usability of the platform for simulation purposes an interaction-centric scenario representing group shaping processes in a multi-cultural context is provided. The scenario is based on Hofstede's concept of 'Cultural Dimensions'. It does not only confirm the applicability of the platform for simulations but also reveals interesting patterns for culturally augmented in- and out-group agents. This explorative research advocates the potential of micro-agents as a powerful general system modelling mechanism while bridging the convergence between mobile and desktop systems. The results stimulate future work on the micro-agent concept itself, the suggested platform and the deeper exploration of mechanisms for seemless interaction of micro-agents with mobile environments. Last but not least the further elaboration of the simulation model as well as its use to augment intelligent agents with cultural aspects offer promising perspectives for future research.
Tractography on HARDI data
(2011)
Diffusion weighted imaging is an important modality in clinical imaging and the only possibility to gain insight into the human brain noninvasively and in-vivo. The applications of this imaging technique are diversified. It is used to study the brain, its structure, development and the functionality of the different areas. Further, important fields of application are neurosurgical planning, examinations of pathologies, investigation of Alzheimer-, strokes, and multiple sclerosis. This thesis gives a brief introduction to MRI and diffusion MRI. Based on this, the mostly used data representation in diffusion MRI in clinical imaging, the diffusion tensor, is introduced. As the diffusion tensor suffers from severe limitations new techniques subsumed under the term HARDI (high angular resolution diffusion imaging) are introduced and discussed in detail. Further, an extensive introduction to tractography, approaches that aim at reconstructing neuronal fibers, is given. Based on the knowledge fromthe theoretical part established tractography algorithms are redesigned to handle HARDI data and, thus, improve the reconstruction of neuronal fibers. Among these algorithms, a novel approach is presented that successfully reconstructs fibers on phantom data as well as on human brain data. Further, a novel global classification approach is presented to cluster voxels according to their diffusion properties.
Identifying reusable legacy code able to implement SOA services is still an open research issue. This master thesis presents an approach to identify legacy code for service implementation based on dynamic analysis and the application of data mining techniques. rnrnAs part of the SOAMIG project, code execution traces were mapped to business processes. Due to the high amount of traces generated by dynamic analyses, the traces must be post-processed in order to provide useful information. rnrnFor this master thesis, two data mining techniques - cluster analysis and link analysis - were applied to the traces. First tests on a Java/Swing legacy system provided good results, compared to an expert- allocation of legacy code.
Magnetic resonance (MR) tomography is an imaging method, that is used to expose the structure and function of tissues and organs in the human body for medical diagnosis. Diffusion weighted (DW) imaging is a specific MR imaging technique, which enables us to gain insight into the connectivity of white matter pathways noninvasively and in vivo. It allows for making predictions about the structure and integrity of those connections. In clinical routine this modality finds application in the planning phase of neurosurgical operations, such as in tumor resections. This is especially helpful if the lesion is deeply seated in a functionally important area, where the risk of damage is given. This work reviews the concepts of MR imaging and DW imaging. Generally, at the current resolution of diffusion weighted data, single white matter axons cannot be resolved. The captured signal rather describes whole fiber bundles. Beside this, it often appears that different complex fiber configurations occur in a single voxel, such as crossings, splittings and fannings. For this reason, the main goal is to assist tractography algorithms who are often confound in such complex regions. Tractography is a method which uses local information to reconstruct global connectivities, i.e. fiber tracts. In the course of this thesis, existing reconstruction methods such as diffusion tensor imaging (DTI) and q-ball imaging (QBI) are evaluated on synthetic generated data and real human brain data, whereas the amount of valuable information provided by the individual reconstruction mehods and their corresponding limitations are investigated. The output of QBI is the orientation distribution function (ODF), where the local maxima coincides with the underlying fiber architecture. We determine those local maxima. Furthermore, we propose a new voxel-based classification scheme conducted on diffusion tensor metrics. The main contribution of this work is the combination of voxel-based classification, local maxima from the ODF and global information from a voxel- neighborhood, which leads to the development of a global classifier. This classifier validates the detected ODF maxima and enhances them with neighborhood information. Hence, specific asymmetric fibrous architectures can be determined. The outcome of the global classifier are potential tracking directions. Subsequently, a fiber tractography algorithm is designed that integrates along the potential tracking directions and is able to reproduce splitting fiber tracts.
Particle swarm optimization is an optimization technique based on simulation of the social behavior of swarms.
The goal of this thesis is to solve 6DOF local pose estimation using a modified particle swarm technique introduced by Khan et al. in 2010. Local pose estimation is achieved by using continuous depth and color data from a RGB-D sensor. Datasets are aquired from different camera poses and registered into a common model. Accuracy and computation time of the implementation is compared to state of the art algorithms and evaluated in different configurations.
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.
The World Wide Web (WWW) has become a very important communication channel. Its usage has steadily grown within the past. Interest by website owners in identifying user behaviour has been around since Tim Berners-Lee developed the first web browser in 1990. But as the influence of the online channel today eclipses all other media the interest in monitoring website usage and user activities has intensified as well. Gathering and analysing data about the usage of websites can help to understand customer behaviour, improve services and potentially increase profit.
It is further essential for ensuring effective website design and management, efficient mass customization and effective marketing. Web Analytics (WA) is the area addressing these considerations. However, changing technologies and evolving Web Analytic methods and processes present a challenge to organisations starting with Web Analytic programmes. Because of lacking resources in different areas and other types of websites especially small and medium-sized enterprises (SME) as well as non-profit organisations struggle to operate WA in an effective manner.
This research project aims to identify the existing gap between theory, tool possibilities and business needs for undertaking Web Analytic programmes. Therefore the topic was looked at from three different ways: the academic literature, Web Analytic tools and an interpretative case study. The researcher utilized an action research approach to investigate Web Analytics presenting an holistic overview and to identify the gaps that exists. The outcome of this research project is an overall framework, which provides guidance for SMEs who operate information websites on how to proceed in a Web Analytic programme.
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.
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.
Object recognition is a well-investigated area in image-based computer vision and several methods have been developed. Approaches based on Implicit Shape Models have recently become popular for recognizing objects in 2D images, which separate objects into fundamental visual object parts and spatial relationships between the individual parts. This knowledge is then used to identify unknown object instances. However, since the emergence of aσordable depth cameras like Microsoft Kinect, recognizing unknown objects in 3D point clouds has become an increasingly important task. In the context of indoor robot vision, an algorithm is developed that extends existing methods based on Implicit Shape Model approaches to the task of 3D object recognition.
Web application testing is an active research area. Garousi et al. did a systematic mapping study and classified 79 papers published between 2000-2011. However, there seems to be a lack of information exchange between the scientific community and tool developers.
This thesis systematically analyzes the field of functional, system level web application testing tools. 194 candidate tools were collected in the tool search and screened, with 23 tools being selected as foundation of this thesis. These 23 tools were systematically used to generate a feature model of the domain. The methodology to support this is an additional contribution of this thesis. It processes end user documentation of tools belonging to an examined domain and creates a feature model. The feature model gives an overview over the existing features, their alternatives and their distribution. It can be used to identify trends and problems, extraordinary features, help decision making of tool purchase or guide scientists how to focus research.
The mitral valve is one of the four valves in the human heart. It is located in the left heart chamber and its function is to control the blood flow from the left atrium to the left ventricle. Pathologies can lead to malfunctions of the valve so that blood can flow back to the atrium. Patients with a faulty mitral valve function may suffer from fatigue and chest pain. The functionality can be surgically restored, which is often a long and exhaustive intervention. Thorough planning is necessary to ensure a safe and effective surgery. This can be supported by creating pre-operative segmentations of the mitral valve. A post-operative analysis can determine the success of an intervention. This work will combine existing and new ideas to propose a new approach to (semi-)automatically create such valve models. The manual part can guarantee a high quality model and reliability, whereas the automatic part contributes to saving valuable labour time.
The main contributions of the automatic algorithm are an estimated semantic separation of the two leaflets of the mitral valve and an optimization process that is capable of finding a coaptation-line and -area between the leaflets. The segmentation method can perform a fully automatic segmentation of the mitral leaflets if the annulus ring is already given. The intermediate steps of this process will be integrated into a manual segmentation method so a user can guide the whole procedure. The quality of the valve models generated by the method proposed in this work will be measured by comparing them to completely manually segmented models. This will show that commonly used methods to measure the quality of a segmentation are too general and do not suffice to reflect the real quality of a model. Consequently the work at hand will introduce a set of measurements that can qualify a mitral valve segmentation in more detail and with respect to anatomical landmarks. Besides the intra-operative support for a surgeon, a segmented mitral valve provides additional benefits. The ability to patient-specifically obtain and objectively describe the valve anatomy may be the base for future medical research in this field and automation allows to process large data sets with reduced expert dependency. Further, simulation methods that use the segmented models as input may predict the outcome of a surgery.