TY - GEN A1 - Hildebrandt, Dieter T1 - A software reference architecture for service-oriented 3D geovisualization systems T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Modern 3D geovisualization systems (3DGeoVSs) are complex and evolving systems that are required to be adaptable and leverage distributed resources, including massive geodata. This article focuses on 3DGeoVSs built based on the principles of service-oriented architectures, standards and image-based representations (SSI) to address practically relevant challenges and potentials. Such systems facilitate resource sharing and agile and efficient system construction and change in an interoperable manner, while exploiting images as efficient, decoupled and interoperable representations. The software architecture of a 3DGeoVS and its underlying visualization model have strong effects on the system's quality attributes and support various system life cycle activities. This article contributes a software reference architecture (SRA) for 3DGeoVSs based on SSI that can be used to design, describe and analyze concrete software architectures with the intended primary benefit of an increase in effectiveness and efficiency in such activities. The SRA integrates existing, proven technology and novel contributions in a unique manner. As the foundation for the SRA, we propose the generalized visualization pipeline model that generalizes and overcomes expressiveness limitations of the prevalent visualization pipeline model. To facilitate exploiting image-based representations (IReps), the SRA integrates approaches for the representation, provisioning and styling of and interaction with IReps. Five applications of the SRA provide proofs of concept for the general applicability and utility of the SRA. A qualitative evaluation indicates the overall suitability of the SRA, its applications and the general approach of building 3DGeoVSs based on SSI. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1131 KW - 3D geovisualization KW - software reference architecture KW - spatial data infrastructure KW - service-oriented architecture KW - standardization KW - image-based representation Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-475831 SN - 1866-8372 IS - 1131 ER - TY - JOUR A1 - Polyvyanyy, Artem A1 - Garcia-Banuelos, Luciano A1 - Fahland, Dirk A1 - Weske, Mathias T1 - Maximal structuring of acyclic process models JF - The computer journal : a publication of the British Computer Society N2 - This article addresses the transformation of a process model with an arbitrary topology into an equivalent structured process model. In particular, this article studies the subclass of process models that have no equivalent well-structured representation but which, nevertheless, can be partially structured into their maximally-structured representation. The transformations are performed under a behavioral equivalence notion that preserves the observed concurrency of tasks in equivalent process models. The article gives a full characterization of the subclass of acyclic process models that have no equivalent well-structured representation, but do have an equivalent maximally-structured one, as well as proposes a complete structuring method. Together with our previous results, this article completes the solution of the process model structuring problem for the class of acyclic process models. KW - process modeling KW - structured process model KW - maximal structuring KW - model transformation KW - fully concurrent bisimulation Y1 - 2014 U6 - https://doi.org/10.1093/comjnl/bxs126 SN - 0010-4620 SN - 1460-2067 VL - 57 IS - 1 SP - 12 EP - 35 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Vogel, Thomas A1 - Giese, Holger T1 - Model-Driven engineering of self-adaptive software with EUREMA JF - ACM transactions on autonomous and adaptive systems N2 - The development of self-adaptive software requires the engineering of an adaptation engine that controls the underlying adaptable software by feedback loops. The engine often describes the adaptation by runtime models representing the adaptable software and by activities such as analysis and planning that use these models. To systematically address the interplay between runtime models and adaptation activities, runtime megamodels have been proposed. A runtime megamodel is a specific model capturing runtime models and adaptation activities. In this article, we go one step further and present an executable modeling language for ExecUtable RuntimE MegAmodels (EUREMA) that eases the development of adaptation engines by following a model-driven engineering approach. We provide a domain-specific modeling language and a runtime interpreter for adaptation engines, in particular feedback loops. Megamodels are kept alive at runtime and by interpreting them, they are directly executed to run feedback loops. Additionally, they can be dynamically adjusted to adapt feedback loops. Thus, EUREMA supports development by making feedback loops explicit at a higher level of abstraction and it enables solutions where multiple feedback loops interact or operate on top of each other and self-adaptation co-exists with offline adaptation for evolution. KW - Design KW - Languages Model-driven engineering KW - modeling language KW - models at runtime KW - model interpreter KW - self-adaptive software KW - feedback loops KW - layered architecture KW - software evolution Y1 - 2014 U6 - https://doi.org/10.1145/2555612 SN - 1556-4665 SN - 1556-4703 VL - 8 IS - 4 PB - Association for Computing Machinery CY - New York ER - TY - JOUR A1 - Yang, Haojin A1 - Quehl, Bernhard A1 - Sack, Harald T1 - A framework for improved video text detection and recognition JF - Multimedia tools and applications : an international journal N2 - Text displayed in a video is an essential part for the high-level semantic information of the video content. Therefore, video text can be used as a valuable source for automated video indexing in digital video libraries. In this paper, we propose a workflow for video text detection and recognition. In the text detection stage, we have developed a fast localization-verification scheme, in which an edge-based multi-scale text detector first identifies potential text candidates with high recall rate. Then, detected candidate text lines are refined by using an image entropy-based filter. Finally, Stroke Width Transform (SWT)- and Support Vector Machine (SVM)-based verification procedures are applied to eliminate the false alarms. For text recognition, we have developed a novel skeleton-based binarization method in order to separate text from complex backgrounds to make it processible for standard OCR (Optical Character Recognition) software. Operability and accuracy of proposed text detection and binarization methods have been evaluated by using publicly available test data sets. KW - Video OCR KW - Video indexing KW - Multimedia retrieval Y1 - 2014 U6 - https://doi.org/10.1007/s11042-012-1250-6 SN - 1380-7501 SN - 1573-7721 VL - 69 IS - 1 SP - 217 EP - 245 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Richter, Rico A1 - Döllner, Jürgen Roland Friedrich T1 - Concepts and techniques for integration, analysis and visualization of massive 3D point clouds JF - Computers, environment and urban systems N2 - Remote sensing methods, such as LiDAR and image-based photogrammetry, are established approaches for capturing the physical world. Professional and low-cost scanning devices are capable of generating dense 3D point clouds. Typically, these 3D point clouds are preprocessed by GIS and are then used as input data in a variety of applications such as urban planning, environmental monitoring, disaster management, and simulation. The availability of area-wide 3D point clouds will drastically increase in the future due to the availability of novel capturing methods (e.g., driver assistance systems) and low-cost scanning devices. Applications, systems, and workflows will therefore face large collections of redundant, up-to-date 3D point clouds and have to cope with massive amounts of data. Hence, approaches are required that will efficiently integrate, update, manage, analyze, and visualize 3D point clouds. In this paper, we define requirements for a system infrastructure that enables the integration of 3D point clouds from heterogeneous capturing devices and different timestamps. Change detection and update strategies for 3D point clouds are presented that reduce storage requirements and offer new insights for analysis purposes. We also present an approach that attributes 3D point clouds with semantic information (e.g., object class category information), which enables more effective data processing, analysis, and visualization. Out-of-core real-time rendering techniques then allow for an interactive exploration of the entire 3D point cloud and the corresponding analysis results. Web-based visualization services are utilized to make 3D point clouds available to a large community. The proposed concepts and techniques are designed to establish 3D point clouds as base datasets, as well as rendering primitives for analysis and visualization tasks, which allow operations to be performed directly on the point data. Finally, we evaluate the presented system, report on its applications, and discuss further research challenges. KW - 3D point clouds KW - System architecture KW - Classification KW - Out-of-core KW - Visualization Y1 - 2014 U6 - https://doi.org/10.1016/j.compenvurbsys.2013.07.004 SN - 0198-9715 SN - 1873-7587 VL - 45 SP - 114 EP - 124 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Buchwald, Sebastian A1 - Wagelaar, Dennis A1 - Dan, Li A1 - Hegedues, Abel A1 - Herrmannsdoerfer, Markus A1 - Horn, Tassilo A1 - Kalnina, Elina A1 - Krause, Christian A1 - Lano, Kevin A1 - Lepper, Markus A1 - Rensink, Arend A1 - Rose, Louis A1 - Waetzoldt, Sebastian A1 - Mazanek, Steffen T1 - A survey and comparison of transformation tools based on the transformation tool contest JF - Science of computer programming N2 - Model transformation is one of the key tasks in model-driven engineering and relies on the efficient matching and modification of graph-based data structures; its sibling graph rewriting has been used to successfully model problems in a variety of domains. Over the last years, a wide range of graph and model transformation tools have been developed all of them with their own particular strengths and typical application domains. In this paper, we give a survey and a comparison of the model and graph transformation tools that participated at the Transformation Tool Contest 2011. The reader gains an overview of the field and its tools, based on the illustrative solutions submitted to a Hello World task, and a comparison alongside a detailed taxonomy. The article is of interest to researchers in the field of model and graph transformation, as well as to software engineers with a transformation task at hand who have to choose a tool fitting to their needs. All solutions referenced in this article provide a SHARE demo. It supported the peer-review process for the contest, and now allows the reader to test the tools online. KW - Graph rewriting KW - Model transformation KW - Tool survey KW - Transformation tool contest Y1 - 2014 U6 - https://doi.org/10.1016/j.scico.2013.10.009 SN - 0167-6423 SN - 1872-7964 VL - 85 SP - 41 EP - 99 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Hildebrandt, Dieter A1 - Timm, Robert T1 - An assisting, constrained 3D navigation technique for multiscale virtual 3D city models JF - Geoinformatica : an international journal on advances of computer science for geographic information systems N2 - Virtual 3D city models serve as integration platforms for complex geospatial and georeferenced information and as medium for effective communication of spatial information. In order to explore these information spaces, navigation techniques for controlling the virtual camera are required to facilitate wayfinding and movement. However, navigation is not a trivial task and many available navigation techniques do not support users effectively and efficiently with their respective skills and tasks. In this article, we present an assisting, constrained navigation technique for multiscale virtual 3D city models that is based on three basic principles: users point to navigate, users are lead by suggestions, and the exploitation of semantic, multiscale, hierarchical structurings of city models. The technique particularly supports users with low navigation and virtual camera control skills but is also valuable for experienced users. It supports exploration, search, inspection, and presentation tasks, is easy to learn and use, supports orientation, is efficient, and yields effective view properties. In particular, the technique is suitable for interactive kiosks and mobile devices with a touch display and low computing resources and for use in mobile situations where users only have restricted resources for operating the application. We demonstrate the validity of the proposed navigation technique by presenting an implementation and evaluation results. The implementation is based on service-oriented architectures, standards, and image-based representations and allows exploring massive virtual 3D city models particularly on mobile devices with limited computing resources. Results of a user study comparing the proposed navigation technique with standard techniques suggest that the proposed technique provides the targeted properties, and that it is more advantageous to novice than to expert users. KW - Virtual 3D city model KW - Multiscale modeling KW - View navigation KW - Virtual camera control KW - Mobile device KW - Distributed 3D geovisualization Y1 - 2014 U6 - https://doi.org/10.1007/s10707-013-0189-8 SN - 1384-6175 SN - 1573-7624 VL - 18 IS - 3 SP - 537 EP - 567 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Westphal, Florian A1 - Axelsson, Stefan A1 - Neuhaus, Christian A1 - Polze, Andreas T1 - VMI-PL: A monitoring language for virtual platforms using virtual machine introspection JF - Digital Investigation : the international journal of digital forensics & incident response N2 - With the growth of virtualization and cloud computing, more and more forensic investigations rely on being able to perform live forensics on a virtual machine using virtual machine introspection (VMI). Inspecting a virtual machine through its hypervisor enables investigation without risking contamination of the evidence, crashing the computer, etc. To further access to these techniques for the investigator/researcher we have developed a new VMI monitoring language. This language is based on a review of the most commonly used VMI-techniques to date, and it enables the user to monitor the virtual machine's memory, events and data streams. A prototype implementation of our monitoring system was implemented in KVM, though implementation on any hypervisor that uses the common x86 virtualization hardware assistance support should be straightforward. Our prototype outperforms the proprietary VMWare VProbes in many cases, with a maximum performance loss of 18% for a realistic test case, which we consider acceptable. Our implementation is freely available under a liberal software distribution license. (C) 2014 Digital Forensics Research Workshop. Published by Elsevier Ltd. All rights reserved. KW - Virtualization KW - Security KW - Monitoring language KW - Live forensics KW - Introspection KW - Classification Y1 - 2014 U6 - https://doi.org/10.1016/j.diin.2014.05.016 SN - 1742-2876 SN - 1873-202X VL - 11 SP - S85 EP - S94 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Ehrig, Hartmut A1 - Golas, Ulrike A1 - Habel, Annegret A1 - Lambers, Leen A1 - Orejas, Fernando T1 - M-adhesive transformation systems with nested application conditions. Part 1: parallelism, concurrency and amalgamation JF - Mathematical structures in computer science : a journal in the applications of categorical, algebraic and geometric methods in computer science N2 - Nested application conditions generalise the well-known negative application conditions and are important for several application domains. In this paper, we present Local Church-Rosser, Parallelism, Concurrency and Amalgamation Theorems for rules with nested application conditions in the framework of M-adhesive categories, where M-adhesive categories are slightly more general than weak adhesive high-level replacement categories. Most of the proofs are based on the corresponding statements for rules without application conditions and two shift lemmas stating that nested application conditions can be shifted over morphisms and rules. Y1 - 2014 U6 - https://doi.org/10.1017/S0960129512000357 SN - 0960-1295 SN - 1469-8072 VL - 24 IS - 4 PB - Cambridge Univ. Press CY - New York ER - TY - JOUR A1 - Marr, Stefan A1 - Pape, Tobias A1 - De Meuter, Wolfgang T1 - Are we there yet? Simple language implementation techniques for the 21st century JF - IEEE software Y1 - 2014 SN - 0740-7459 SN - 1937-4194 VL - 31 IS - 5 SP - 60 EP - 67 PB - Inst. of Electr. and Electronics Engineers CY - Los Alamitos ER -