TY - JOUR A1 - Richter, Rico A1 - Döllner, Jürgen Roland Friedrich T1 - Integrated real-time visualisation of massive 3D-Point clouds and geo-referenced textured dates JF - Photogrammetrie, Fernerkundung, Geoinformation Y1 - 2011 SN - 1432-8364 IS - 3 SP - 145 EP - 154 PB - Schweizerbart CY - Stuttgart ER - TY - JOUR A1 - Kühne, Ralph A1 - Huitema, George A1 - Carle, Georg T1 - A simple distributed mechanism for accounting system self-configuration in next-generation charging and billing JF - Computer communications N2 - Modern communication systems are becoming increasingly dynamic and complex. In this article a novel mechanism for next generation charging and billing is presented that enables self-configurability for accounting systems consisting of heterogeneous components. The mechanism is required to be simple, effective, efficient, scalable and fault-tolerant. Based on simulation results it is shown that the proposed simple distributed mechanism is competitive with usual cost-based or random mechanisms under realistic assumptions and up to non-extreme workload situations as well as fulfilling the posed requirements. KW - Charging KW - Billing KW - Accounting KW - Self-configuration KW - Communication systems Y1 - 2011 U6 - https://doi.org/10.1016/j.comcom.2010.10.012 SN - 0140-3664 VL - 34 IS - 7 SP - 898 EP - 920 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bog, Anja A1 - Plattner, Hasso A1 - Zeier, Alexander T1 - A mixed transaction processing and operational reporting benchmark JF - Information systems frontiers N2 - The importance of reporting is ever increasing in today's fast-paced market environments and the availability of up-to-date information for reporting has become indispensable. Current reporting systems are separated from the online transaction processing systems (OLTP) with periodic updates pushed in. A pre-defined and aggregated subset of the OLTP data, however, does not provide the flexibility, detail, and timeliness needed for today's operational reporting. As technology advances, this separation has to be re-evaluated and means to study and evaluate new trends in data storage management have to be provided. This article proposes a benchmark for combined OLTP and operational reporting, providing means to evaluate the performance of enterprise data management systems for mixed workloads of OLTP and operational reporting queries. Such systems offer up-to-date information and the flexibility of the entire data set for reporting. We describe how the benchmark provokes the conflicts that are the reason for separating the two workloads on different systems. In this article, we introduce the concepts, logical data schema, transactions and queries of the benchmark, which are entirely based on the original data sets and real workloads of existing, globally operating enterprises. KW - Benchmarking KW - Mixed workload KW - OLTP KW - Operational reporting Y1 - 2011 U6 - https://doi.org/10.1007/s10796-010-9283-8 SN - 1387-3326 VL - 13 IS - 3 SP - 321 EP - 335 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Lincke, Jens A1 - Appeltauer, Malte A1 - Steinert, Bastian A1 - Hirschfeld, Robert T1 - An open implementation for context-oriented layer composition in ContextJS JF - Science of computer programming N2 - Context-oriented programming (COP) provides dedicated support for defining and composing variations to a basic program behavior. A variation, which is defined within a layer, can be de-/activated for the dynamic extent of a code block. While this mechanism allows for control flow-specific scoping, expressing behavior adaptations can demand alternative scopes. For instance, adaptations can depend on dynamic object structure rather than control flow. We present scenarios for behavior adaptation and identify the need for new scoping mechanisms. The increasing number of scoping mechanisms calls for new language abstractions representing them. We suggest to open the implementation of scoping mechanisms so that developers can extend the COP language core according to their specific needs. Our open implementation moves layer composition into objects to be affected and with that closer to the method dispatch to be changed. We discuss the implementation of established COP scoping mechanisms using our approach and present new scoping mechanisms developed for our enhancements to Lively Kernel. KW - ContextJS KW - Context-oriented programming KW - Open implementations KW - Dynamic adaptation KW - Scope Y1 - 2011 U6 - https://doi.org/10.1016/j.scico.2010.11.013 SN - 0167-6423 VL - 76 IS - 12 SP - 1194 EP - 1209 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Henkler, Stefan A1 - Oberthuer, Simon A1 - Giese, Holger A1 - Seibel, Andreas T1 - Model-driven runtime resource predictions for advanced mechatronic systems with dynamic data structures JF - Computer systems science and engineering N2 - The next generation of advanced mechatronic systems is expected to enhance their functionality and improve their performance by context-dependent behavior. Therefore, these systems require to represent information about their complex environment and changing sets of collaboration partners internally. This requirement is in contrast to the usually assumed static structures of embedded systems. In this paper, we present a model-driven approach which overcomes this situation by supporting dynamic data structures while still guaranteeing that valid worst-case execution times can be derived. It supports a flexible resource manager which avoids to operate with the prohibitive coarse worst-case boundaries but instead supports to run applications in different profiles which guarantee different resource requirements and put unused resources in a profile at other applications' disposal. By supporting the proper estimation of worst case execution time (WCET) and worst case number of iteration (WCNI) at runtime, we can further support to create new profiles, add or remove them at runtime in order to minimize the over-approximation of the resource consumption resulting from the dynamic data structures required for the outlined class of advanced systems. KW - Model-Driven Engineering KW - Safety Critical Systems KW - Dynamic Data Structures KW - Flexible Resource Manager KW - Runtime WCET Analysis Y1 - 2011 SN - 0267-6192 VL - 26 IS - 6 SP - 505 EP - 518 PB - IOP Publ. Ltd. CY - Leicester ER - TY - JOUR A1 - Decker, Gero A1 - Weske, Mathias T1 - Interaction-centric modeling of process choreographies JF - Information systems N2 - With the rise of electronic integration between organizations, the need for a precise specification of interaction behavior increases. Information systems, replacing interaction previously carried out by humans via phone, faxes and emails, require a precise specification for handling all possible situations. Such interaction behavior is described in process choreographies. While many proposals for choreography languages have already been made, most of them fall into the category of interconnection models, where the observable behavior of the different partners is described and then related via message flow. As this article will show, this modeling approach fails to support fundamental design principles of choreographies and typically leads to modeling errors. This motivates an alternative modeling style, namely interaction modeling, for overcoming these limitations. While the main concepts are independent of a concrete modeling language, iBPMN is introduced as novel interaction modeling language. Formal execution semantics are provided and a comprehensive toolset implementing the approach is presented. KW - Choreographies KW - B2B process integration KW - Interaction modeling KW - Business Process Modeling Notation Y1 - 2011 U6 - https://doi.org/10.1016/j.is.2010.06.005 SN - 0306-4379 VL - 36 IS - 2 SP - 292 EP - 312 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Awad, Ahmed Mahmoud Hany Aly A1 - Weidlich, Matthias A1 - Weske, Mathias T1 - Visually specifying compliance rules and explaining their violations for business processes JF - Journal of visual languages and computing N2 - A business process is a set of steps designed to be executed in a certain order to achieve a business value. Such processes are often driven by and documented using process models. Nowadays, process models are also applied to drive process execution. Thus, correctness of business process models is a must. Much of the work has been devoted to check general, domain-independent correctness criteria, such as soundness. However, business processes must also adhere to and show compliance with various regulations and constraints, the so-called compliance requirements. These are domain-dependent requirements. In many situations, verifying compliance on a model level is of great value, since violations can be resolved in an early stage prior to execution. However, this calls for using formal verification techniques, e.g., model checking, that are too complex for business experts to apply. In this paper, we utilize a visual language. BPMN-Q to express compliance requirements visually in a way similar to that used by business experts to build process models. Still, using a pattern based approach, each BPMN-Qgraph has a formal temporal logic expression in computational tree logic (CTL). Moreover, the user is able to express constraints, i.e., compliance rules, regarding control flow and data flow aspects. In order to provide valuable feedback to a user in case of violations, we depend on temporal logic querying approaches as well as BPMN-Q to visually highlight paths in a process model whose execution causes violations. KW - Business process modeling KW - Compliance checking KW - Visual modeling KW - Anti-patterns Y1 - 2011 U6 - https://doi.org/10.1016/j.jvlc.2010.11.002 SN - 1045-926X VL - 22 IS - 1 SP - 30 EP - 55 PB - Elsevier CY - London ER - TY - JOUR A1 - Weidlich, Matthias A1 - Polyvyanyy, Artem A1 - Mendling, Jan A1 - Weske, Mathias T1 - Causal behavioural profiles - efficient computation, applications, and evaluation JF - Fundamenta informaticae N2 - Analysis of behavioural consistency is an important aspect of software engineering. In process and service management, consistency verification of behavioural models has manifold applications. For instance, a business process model used as system specification and a corresponding workflow model used as implementation have to be consistent. Another example would be the analysis to what degree a process log of executed business operations is consistent with the corresponding normative process model. Typically, existing notions of behaviour equivalence, such as bisimulation and trace equivalence, are applied as consistency notions. Still, these notions are exponential in computation and yield a Boolean result. In many cases, however, a quantification of behavioural deviation is needed along with concepts to isolate the source of deviation. In this article, we propose causal behavioural profiles as the basis for a consistency notion. These profiles capture essential behavioural information, such as order, exclusiveness, and causality between pairs of activities of a process model. Consistency based on these profiles is weaker than trace equivalence, but can be computed efficiently for a broad class of models. In this article, we introduce techniques for the computation of causal behavioural profiles using structural decomposition techniques for sound free-choice workflow systems if unstructured net fragments are acyclic or can be traced back to S-or T-nets. We also elaborate on the findings of applying our technique to three industry model collections. KW - Causal Behavioural Profiles KW - Formal Methods KW - Behavioural Abstraction KW - Structural Decomposition KW - Exclusiveness KW - Concurrency KW - Order Relations KW - Causality KW - Optionality Y1 - 2011 U6 - https://doi.org/10.3233/FI-2011-614 SN - 0169-2968 VL - 113 IS - 3-4 SP - 399 EP - 435 PB - IOS Press CY - Amsterdam ER - TY - JOUR A1 - Weidlich, Matthias A1 - Polyvyanyy, Artem A1 - Desai, Nirmit A1 - Mendling, Jan A1 - Weske, Mathias T1 - Process compliance analysis based on behavioural profiles JF - Information systems N2 - Process compliance measurement is getting increasing attention in companies due to stricter legal requirements and market pressure for operational excellence. In order to judge on compliance of the business processing, the degree of behavioural deviation of a case, i.e., an observed execution sequence, is quantified with respect to a process model (referred to as fitness, or recall). Recently, different compliance measures have been proposed. Still, nearly all of them are grounded on state-based techniques and the trace equivalence criterion, in particular. As a consequence, these approaches have to deal with the state explosion problem. In this paper, we argue that a behavioural abstraction may be leveraged to measure the compliance of a process log - a collection of cases. To this end, we utilise causal behavioural profiles that capture the behavioural characteristics of process models and cases, and can be computed efficiently. We propose different compliance measures based on these profiles, discuss the impact of noise in process logs on our measures, and show how diagnostic information on non-compliance is derived. As a validation, we report on findings of applying our approach in a case study with an international service provider. KW - Process compliance KW - Compliance measurement KW - Log conformance KW - Root cause analysis Y1 - 2011 U6 - https://doi.org/10.1016/j.is.2011.04.002 SN - 0306-4379 VL - 36 IS - 7 SP - 1009 EP - 1025 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Laue, Ralf A1 - Awad, Ahmed Mahmoud Hany Aly T1 - Visual suggestions for improvements in business process diagrams JF - Journal of visual languages and computing N2 - Business processes are commonly modeled using a graphical modeling language. The most widespread notation for this purpose is business process diagrams in the Business Process Modeling Notation (BPMN). In this article, we use the visual query language BPMN-Q for expressing patterns that are related to possible problems in such business process diagrams. We discuss two classes of problems that can be found frequently in real-world models: sequence flow errors and model fragments that can make the model difficult to understand. By using a query processor, a business process modeler is able to identify possible errors in business process diagrams. Moreover, the erroneous parts of the business process diagram can be highlighted when an instance of an error pattern is found. This way, the modeler gets an easy-to-understand feedback in the visual modeling language he or she is familiar with. This is an advantage over current validation methods, which usually lack this kind of intuitive feedback. KW - Business process model KW - Business process diagram KW - BPMN-Q KW - Visualization Y1 - 2011 U6 - https://doi.org/10.1016/j.jvlc.2011.04.003 SN - 1045-926X VL - 22 IS - 5 SP - 385 EP - 399 PB - Elsevier CY - London ER - TY - JOUR A1 - Protzmann, Robert A1 - Schünemann, Bjoern A1 - Radusch, Ilja T1 - The Influences of communication models on the simulated effectiveness of V2X Applications JF - IEEE communications magazine N2 - In this article, we aim to evaluate the influences of different propagation models on the results of V2X simulations. First, we analyze how the models free space propagation, Rayleigh fading, and Ricean fading in synthetic scenarios with and without background communication influence the simulation of communication in general. After that, we investigate the impact of the models on the simulated behavior of a V2X traffic efficiency application in a real inner city scenario. Our results show that the selection of the propagation model affects the number of delivered messages, but exerts no significant influence on the simulated effectiveness of a V2X traffic efficiency application in urban areas. Under those circumstances, a simplified propagation model is sufficient. Y1 - 2011 SN - 0163-6804 VL - 49 IS - 11 SP - 149 EP - 155 PB - Inst. of Electr. and Electronics Engineers CY - Piscataway ER - TY - JOUR A1 - Wist, Dominic A1 - Schaefer, Mark A1 - Vogler, Walter A1 - Wollowski, Ralf T1 - Signal transition graph decomposition internal communication for speed independent circuit implementation JF - IET Computers and digital techniques N2 - Logic synthesis of speed independent circuits based on signal transition graph (STG) decomposition is a promising approach to tackle complexity problems like state-space explosion. Unfortunately, decomposition can result in components that in isolation have irreducible complete state coding conflicts. In earlier work, the authors showed how to resolve such conflicts by introducing internal communication between components, but only for very restricted specification structures. Here, they improve their former work by presenting algorithms for identifying delay transitions and inserting gyroscopes for specifications having a much more general structure. Thus, the authors are now able to synthesise controllers from real-life specifications. For all algorithms, they present correctness proofs and show their successful application to benchmarks, including very complex STGs arising in the context of control resynthesis. Y1 - 2011 U6 - https://doi.org/10.1049/iet-cdt.2010.0162 SN - 1751-8601 VL - 5 IS - 6 SP - 440 EP - 451 PB - Institution of Engineering and Technology CY - Hertford ER - TY - JOUR A1 - Yeung, Ching-man Au A1 - Noll, Michael G. A1 - Gibbins, Nicholas A1 - Meinel, Christoph A1 - Shadbolt, Nigel T1 - Spear spamming-resistant expertise analysis and ranking incollaborative tagging systems JF - Computational intelligence N2 - In this article, we discuss the notions of experts and expertise in resource discovery in the context of collaborative tagging systems. We propose that the level of expertise of a user with respect to a particular topic is mainly determined by two factors. First, an expert should possess a high-quality collection of resources, while the quality of a Web resource in turn depends on the expertise of the users who have assigned tags to it, forming a mutual reinforcement relationship. Second, an expert should be one who tends to identify interesting or useful resources before other users discover them, thus bringing these resources to the attention of the community of users. We propose a graph-based algorithm, SPEAR (spamming-resistant expertise analysis and ranking), which implements the above ideas for ranking users in a folksonomy. Our experiments show that our assumptions on expertise in resource discovery, and SPEAR as an implementation of these ideas, allow us to promote experts and demote spammers at the same time, with performance significantly better than the original hypertext-induced topic search algorithm and simple statistical measures currently used in most collaborative tagging systems. KW - collaborative tagging KW - expertise KW - folksonomy KW - HITS KW - ranking KW - spamming Y1 - 2011 U6 - https://doi.org/10.1111/j.1467-8640.2011.00384.x SN - 0824-7935 SN - 1467-8640 VL - 27 IS - 3 SP - 458 EP - 488 PB - Wiley-Blackwell CY - Hoboken ER -