The KLU faculty, post-docs, and PhD candidates regularly publish the results of their research in scientific journals. You will find a complete overview of all KLU publications below (e.g. articles in peer-reviewed journals, professional journals, books, working papers, and conference proceedings). Search for relevant terms and keywords, or filter the list by name, year of publication or type of publication. The references include DOIs and abstracts where available, and you can download them to your own reference database or platform. We regularly update the database with new publications.

Books

Conference Proceedings

Copy reference link   DOI: 10.1016/j.trpro.2017.05.374

Abstract: The objective of this study is to understand how and to what extend illegal parking should be legalized, giving the benefit for parking users, urban planning, and transport planning. From literature, the policies and theories based on the lessons from other countries have provided the basis that can be applied in investigating a new parking management paradigm. Empirical surveys are conducted to examine the parking conditions, parking user’s behavior and the consequence of illegal parking spaces in the core city center in Hanoi, Vietnam. Then, the requirements of para-parking (legalization of illegal parking spaces) are formulated including the change process that involves parking authorities, parking operators, and parking users. An in-depth analyze is undertaken to look at opportunities, risks and forms of para-parking and finally a proposal for a qualitative economic impact assessment of parking facility investment is given.

Export record: Citavi Endnote RIS ISI BibTeX WordXML

Copy reference link   DOI: 10.1016/j.trpro.2017.05.479

Abstract: Integrating the decisions and the behavior of Logistics Service Providers (LSPs) into freight transport models is essential to be capable of accurately describing future developments in freight transport systems. Knowledge on the spatial distribution patterns of LSP locations, e.g. to represent network routing of shipments more accurately, is of paramount importance. Moreover, attributes characterizing the LSP locations are helpful to relate them to traffic generation. Therefore, the objective of this paper is to present intermediate results of an empirical study on LSP locations in Germany. Drawing on these findings, the freight generated by German less than truckload networks is estimated on an aggregate level. These findings shed some light on the spatial and structural patterns of the locations allocable to the German logistics sector and the freight transport it generates. These insights are highly relevant for freight transport and land use planning policies.

Export record: Citavi Endnote RIS ISI BibTeX WordXML

Copy reference link  

Abstract: With an ongoing division of labor and concentration on core competencies in logistics, the flexibility and quality in logistics services can be increased in terms of contracting specialists for each step in a supply chain. In order to participate in such an environment and act successfully on the market, it is essential for logistics service providers to follow a service oriented paradigm and modularize their service portfolio from static end-to-end solutions to a flexible set of modular services. One of the main challenges is to find a ’suitable’ level of granularity for the modularization of existing logistics services. In this paper a conceptual framework of service granularity levels is developed. A systematic literature review is conducted in order to find existing concepts of service granularity. Findings are analyzed and finally synthesized towards their suitability for logistics services. Domain specific composition is supported by the logistics service map concept that contains catalog and construction kit for modular services. The paper’s contribution is a Service Granularity Framework dedicated to specialized scholars of service science and practitioners of logistics.

Export record: Citavi Endnote RIS ISI BibTeX WordXML

Copy reference link   DOI: 10.5220/0005918500390047

Abstract: Utility, defined as the perceived satisfaction with a service, provides the ideal means for decision making on the level of individual entities and collectives participating in a large-scale dynamic system. Previous works have already introduced the concept into the area of collective adaptive systems, and have discussed what is the necessary infrastructure to support the realization of the involved theoretical concepts into actual decision making. In this work we focus on two aspects. First, we provide a concrete utility model for a case study that is part of a larger research project. Second, we incorporate this model into our implementation of the proposed architecture. More importantly, we design and execute an experiment that aims to empirically evaluate the use of utility for decision making by comparing it against simpler decision making mechanisms.

Export record: Citavi Endnote RIS ISI BibTeX WordXML

Copy reference link   DOI: 10.1007/978-3-319-19027-3_23

Abstract: Global demands and emerging markets resulted in a rise of complexity in logistics over the last years. Furthermore, producing companies outsourced their logistics for reasons of flexibility. Hence, clients consult solution specialists for customer-focused end-to-end processes. The 4th party logistics business model offers an overall service management throughout an entire logistics chain by planning and controlling inherent processes. But because physical provisioning is outsourced to 3rd party providers, performance measurement is essential in order to meet service levels. Measuring sub providers poses difficulties because of different process definitions and communication standards. A relief is the growing amount of information during the process lifecycle. In this paper we present an integrated, strategically aligned provider rating model, applicable throughout the entire logistics process and capable of summing up operational information into ratios that are further aggregated into key performance indicators. Thereafter, we prove its applicability through a prototypical implementation.

Export record: Citavi Endnote RIS ISI BibTeX WordXML

Copy reference link   DOI: 10.5220/0005342000280036

Abstract: The concept of reuse in process models is extensively studied in the literature. Sub-processes, process templates,process variants, and process reference models are employed as reusable elements for process modeling.Additionally, the notion of process fragments has been introduced to capture parts of a process model and store them for later reuse. In contrast, concepts for reuse of processes that cross the boundaries of organizations, i.e., choreographies, have not yet been studied in the appropriate level of detail. In this paper, we introduce the concept of choreography fragments as reusable elements for choreography modeling. Choreography fragments can be extracted from choreography models, adapted, stored, and inserted into new models. We provide a formal model for choreography fragments and identify a set of patterns constituting frequently occurring meaningful choreography fragments.

Export record: Citavi Endnote RIS ISI BibTeX WordXML

Copy reference link   DOI: 10.1109/CloudCom.2015.86

Abstract: The on-demand provisioning of services, a cloud-based extension for traditional service-oriented architectures, improves the handling of services in usage scenarios where they are only used rarely and irregularly. However, the standard process of service provisioning and de-provisioning shows still some shortcomings when applying it in real world. In this paper, we introduce a middleware-centric optimization approach that can be integrated in the existing on-demand provisioning middleware in a loosely coupled manner, changing the standard provisioning and de-provisioning behavior in order to improve it with respect to cost and time. We define and implement a set of optimization strategies, evaluate them based on a real world use case from the eScience domain and provide qualitative as well as quantitative decision support for effectively selecting and parametrizing a suitable strategy. Altogether, our work improves the applicability of the existing on-demand provisioning approach and system in real world, including guidance for selecting the suitable optimization strategy for specific use cases.

Export record: Citavi Endnote RIS ISI BibTeX WordXML

Copy reference link   DOI: 10.1109/ICWS.2015.96

Abstract: Reuse of service orchestrations or service compositions is extensively studied in the literature of process modeling. Sub-processes, process templates, process variants, and process reference models are employed as reusable elements for these purposes. The concept of process fragments has been previously introduced in order to capture parts of a process model and store them for later reuse. However, similar efforts on facilitating the reuse of processes that cross the boundaries of organizations expressed as service choreographies are not available yet. In this paper, we introduce the concept of choreography fragments as reusable elements for service choreography modeling. Choreography fragments can be extracted from choreography models, adapted, stored, and later inserted into new models. Based on a formal model for choreography fragments, we define methods and algorithms for the extraction and insertion of fragments from and into service choreographies. We then discuss an experimental and proof-of-concept evaluation of our proposal.

Export record: Citavi Endnote RIS ISI BibTeX WordXML

Copy reference link   DOI: doi:10.1007/978-3-319-26148-5_22

Abstract: Scientists that use the workflow paradigm for the enactment of scientific experiments need support for trial-and-error modeling, as well as flexibility mechanisms that enable the ad hoc repetition of workflow logic for the convergence of results or error handling. Towards this goal, in this paper we introduce the facilities to repeat partially or completely running choreographies on demand. Choreographies are interesting for the scientific workflow community because so-called multi-scale/field (multi-*) experiments can be modeled and enacted as choreographies of scientific workflows. A prerequisite for choreography repetition is the rewinding of the involved participant instances to a previous state. For this purpose, we define a formal model representing choreography models and their instances as well as a concept to repeat choreography logic. Furthermore, we provide an algorithm for determining the rewinding points in each involved participant instance.

Export record: Citavi Endnote RIS ISI BibTeX WordXML

Copy reference link  

Abstract: Due to strong interdependencies between production, logistics and traffic, a decision in one of these fields has impacts on the others. However, decision makers in and around today’s supply chains rarely consider effects of their decisions on other participants of the supply chain or the traffic system. Thus, a tool for decision support, which clearly illustrates the variety of impacts of a decision, is highly desirable. Accordingly, this paper presents a reference model in the context of production, logistics and traffic, called Interdisciplinary Decision Map (IDM). The IDM allows for describing and analyzing interdisciplinary impacts of decisions across the disciplines. Thus, it can serve as decision support tool for decision makers out of the considered domains. The IDM’s applicability is demonstrated by using it to analyze selected impacts of an heavy goods vehicles (HGV) toll’s introduction on production, logistics and traffic.

Export record: Citavi Endnote RIS ISI BibTeX WordXML

Copy reference link   DOI: 10.5220/0005377801660176

Abstract: The objective of tactical planning in logistics is the engineering and evaluation of processes within a given set of possible alternatives. Due to outsourcing and a division of labor, a high number of participants, available services and thus possible process alternatives arises within logistics networks. The additional wide range of service description and annotation methods result in a complex planning process. In order to support planning, a semi-automated approach is presented in this paper that is based on a combined catalog and construction system (for engineering) and a generic simulation approach (for evaluation) that are able to handle the variety of description and annotation methods. The basic concepts are presented and afterward associated by a model-driven approach in order to connect them and make them compatible to work with each other. Finally, a method is developed to foster a semi-automated engineering and evaluation of process alternatives.

Export record: Citavi Endnote RIS ISI BibTeX WordXML

Copy reference link

Abstract: The success of the Cloud computing paradigm, together with the increase of Cloud providers and optimized Infrastructure-as-a-Service (IaaS) offerings have contributed to a raise in the number of research and industry communities that are strong supporters of migrating and running their applications in the Cloud. Focusing on eScience simulation-based applications, scientific workflows have been widely adopted in the last years, and the scientific workflow management systems have become strong candidates for being migrated to the Cloud. In this research work we aim at empirically evaluating multiple Cloud providers and their corresponding optimized and non-optimized IaaS offerings with respect to their offered performance, and its impact on the incurred monetary costs when migrating and executing a workflow-based simulation environment. The experiments show significant performance improvements and reduced monetary costs when executing the simulation environment in off-premise Clouds.

Export record: Citavi Endnote RIS ISI BibTeX WordXML

Copy reference link   DOI: 10.1109/UCC.2014.37

Abstract: In many modern systems, applications or services are realized as compositions of multiple existing services that can be enacted by Service Composition Engines (SCEs), which provide the required functionality to enable their definition and execution. SCEs typically use the capabilities of an Enterprise Service Bus (ESB) which serves as the messaging hub between the composed services aiming at ensuring their integration. Together, an SCE and ESB solution comprise the service middleware required for the definition and execution of service-based composite applications. Offering a service middleware solution as a service creates a PaaS offering that allows the service consumers to share the service middleware solution in a multi-tenant manner. However, multi-tenancy support for service middleware solutions remains an open issue. For this purpose, in this work we introduce a general architecture for the realization of a multi-tenant service middleware PaaS solution. This architecture is prototypically realized based on open-source, multi-tenant ESB and SCE solutions. The resulting service middleware provides configurability for service compositions, tenant-aware messaging, and tenant-based administration and management of the SCE and the ESB. We also present an empirical evaluation of the multi-tenant service middleware with focus on the SCE. The results of these experiments show a performance degradation within acceptable limits when scaling the number of tenants and tenant users.

Export record: Citavi Endnote RIS ISI BibTeX WordXML

Copy reference link   DOI: doi:10.1007/978-3-662-45563-0_6

Abstract: Collaborative, Dynamic & Complex (CDC) systems such as adaptive pervasive systems, eScience applications, and complex business systems inherently require modeling and run time flexibility. Since domain problems in CDC systems are expressed as service choreographies and enacted by service orchestrations, we propose an approach introducing placeholder modeling constructs usable both on the level of choreographies and orchestrations, and a classification of strategies for their refinement to executable workflows. These abstract modeling constructs allow deferring the modeling decisions to later points in the life cycle of choreographies. This supports run time scenarios such as incorporating new participants into a choreography after its enactment has started or enhancing the process logic of some of the participants. We provide a prototypical implementation of the approach and evaluate it by means of a case study.

Export record: Citavi Endnote RIS ISI BibTeX WordXML

Copy reference link   DOI: 10.5220/0004852402760286

Abstract: Service orientation has significantly facilitated the development of complex distributed systems spanning multiple organizations. However, different application areas approach such systems in domain-specific ways, focusing only on particular aspects relevant for their application types. As a result, we observe a very fragmented landscape of service-oriented systems, which does not enable collaboration across organizations. To address this concern, in this work we introduce the notion of Collaborative, Dynamic and Complex (CDC) systems and position them with respect to existing technologies. In addition, we present how CDC systems are modeled and the steps to provision and execute them. Furthermore, we contribute an architecture and prototypical implementation, which we evaluate by means of a case study in a Cloud-enabled context-aware pervasive application.

Export record: Citavi Endnote RIS ISI BibTeX WordXML

Copy reference link   DOI: 10.5220/0004937403080314

Abstract: Large-scale systems comprising of multiple heterogeneous entities are directly influenced by the interactions of their participating entities. Such entities, both physical and virtual, attempt to satisfy their objectives by dynamically collaborating with each other, and thus forming collective adaptive systems. These systems are subject to the dynamicity of the entities’ objectives, and to changes to the environment. In this work we focus on the latter, i.e. on providing the means for entities in such systems to model, monitor and evaluate their perceived utility by participating in the system. This allows for them to make informed decisions about their interactions with other entities in the system. For this purpose we propose a utility-based approach for decision making, as well as an architecture that allows for the support of this approach.

Export record: Citavi Endnote RIS ISI BibTeX WordXML

Copy reference link   DOI: 10.1007/978-3-319-06695-0_16

Abstract: With the principle of division of labor in logistics, an integrator can focus on planning and monitoring within a network, while subsidiary logistics service providers (LSPs) are responsible for the actual physical manipulation of goods. Because of heterogeneous service descriptions, processes and IT-systems, the integrator requires a platform that provides the ability to interact with LSPs and to plan, execute and monitor contracts for integrator’s customers. Such an integration platform is currently developed in the research project Logistics Service Engineering & Management. Crucial to such a platform is the ability to maintain a complete catalog and to efficiently identify and choose appropriate services. In this paper a metamodel-based approach is presented facing these requirements.

Export record: Citavi Endnote RIS ISI BibTeX WordXML

Copy reference link   DOI: 10.1109/EDOC.2014.25

Abstract: Service selection is an important concept in service oriented architectures that enables the dynamic binding of services based on functional and non-functional requirements. The introduction of the concept of on-demand provisioned services significantly changes the nature of services and as a consequence the traditional service selection process does not fit anymore. Existing approaches for service selection rely on the always on semantic of services, an assumption that is not valid for on-demand provisioned services. We tackle this problem by adapting the traditional service selection process and by defining an additional step covering the changes introduced by the concept of on-demand provisioning. Our solution comprises an extended architecture for on-demand provisioning, a metamodel for a service registry, and a detailed definition and discussion of the adapted and extended service selection process. The work presented in this paper allows keeping the advantages of dynamic service binding at runtime and combining them with the advantages of Cloud computing exploited through the concept of on-demand provisioning.

Export record: Citavi Endnote RIS ISI BibTeX WordXML