% % This file was created by the Typo3 extension % sevenpack version 0.7.16 % % --- Timezone: CEST % Creation date: 2013-06-19 % Creation time: 00-18-22 % --- Number of references % 29 % @Article { Auer2011a, title = {Target-Oriented Self-Structuring in Classifying Cellular Automata}, journal = {Journal of Cellular Automata (JCA)}, year = {2011}, volume = {6}, number = {1}, pages = {3--23}, abstract = {Some cellular automata are able to solve classification problems on their initial configuration by building globally visible structures. However, no formal measures exist yet for describing or detecting this behavior in general. The lack of such formal methods often leads to quite observer-dependent discussions of emergent computation. In this paper, we propose the measures of target orientation and self-structuring that allow to formally evaluate a cellular automaton}, keywords = {One-dimensional cellular automata; Classification problem; Emergent computation; Formal measures}, tags = {AutoI, EuroNF, ResumeNet, Socionical}, url = {http://www.net.fim.uni-passau.de/pdf/Auer2011a.pdf}, web_url = {http://www.oldcitypublishing.com/JCA/JCAcontents/JCAv6n1contents.html}, ISSN = {1557-5969 (Print); 1557-5977 (Online)}, author = {Auer, Christopher and Wuechner, Patrick and De Meer, Hermann} } @Article { Holzer2010a, title = {Modeling of Self-Organizing Systems: An Overview}, journal = {Electronic Communications of the EASST}, year = {2010}, volume = {27}, pages = {1--12}, abstract = {This paper gives a systematic overview on modeling formalisms suitable for modeling self-organizing systems. We distinguish between micro-level modeling and macro-level modeling. On the micro level, the behavior of each entity and the interaction between different object must be described by the model. Macro-level modeling abstracts from the individual entities and only looks at the behavior of the system variables of interest. The differentiations between discrete and continuous time and between discrete and continuous state space lead to different descriptions of the model.}, keywords = {Self-Organization; Modeling; Systems}, tags = {Socionical, ResumeNet, EuroNF}, url = {http://www.net.fim.uni-passau.de/pdf/Holzer2010a.pdf}, web_url = {http://journal.ub.tu-berlin.de/index.php/eceasst/article/view/385/359}, publisher = {EASST}, booktitle = {{W}orkshop ueber {S}elbstorganisierende, adaptive, kontextsensitive verteilte {S}ysteme ({SAKS} 2010)}, ISSN = {1863-2122}, author = {Holzer, Richard and Wuechner, Patrick and De Meer, Hermann} } @Article { Wuechner2009a, title = {Finite-source {M/M/S} retrial queue with search for balking and impatient customers from the orbit}, journal = {Computer Networks (ComNet)}, year = {2009}, volume = {53}, number = {8}, pages = {1264--1273}, abstract = {The present paper deals with a generalization of the homogeneous multi-server finite-source retrial queue with search for customers in the orbit. The novelty of the investigation is the introduction of balking and impatience for requests who arrive at the service facility with a limited capacity and FIFO queue. Arriving customers may balk, i.e., they either join the queue or go to the orbit. Moreover, the requests are impatient and abandon the buffer after a random time and enter the orbit, too. In case of an empty buffer, each server searches for a customer in the orbit after finishing service. All random variables involved in the model construction are supposed to be exponentially distributed and independent of each other. The primary aim of this analysis is to show the effect of balking, impatience, and buffer size on the steady-state performance measures. Concentrating on the mean response time, several numerical examples are investigated by the help of the MOSEL-2 tool used for creating the model and calculating the stationary characteristics.}, note = {Performance of Computer Networks: Special Issue in Memory of Dr. Gunter Bolch.}, keywords = {Performance modeling; Finite-source retrial queues; Orbital search; Balking customers; Impatient customers; MOSEL-2}, tags = {AutoI, DFG_MathMod, EuroNF, ResumeNet, MOSEL2}, url = {http://www.net.fim.uni-passau.de/pdf/Wuechner2009a.pdf}, publisher = {Elsevier B.V.}, DOI = {10.1016/j.comnet.2009.02.015}, author = {Wuechner, Patrick and Sztrik, Janos and De Meer, Hermann} } @Article { Wuechner2009b, title = {Investigating the mean response time in finite-source retrial queues using the algorithm by {Gaver}, {Jacobs}, and {Latouche}}, journal = {Annales Mathematicae et Informaticae (AMI)}, year = {2009}, volume = {36}, pages = {143--160}, abstract = {In this paper, we discuss the maximum of the mean response time that appears in finite-source retrial queues with orbital search when the arrival rate is varied. We show that explicit closed-form equations of the mean response time can be derived by exploiting the block-structure of the finite Markov chain underlying the model and using an efficient computational algorithm proposedby Gaver, Jacobs, and Latouche. However, we also show that already for the discussed relatively simple model, the resulting equation is rather complex which hampers further evaluation.}, keywords = {Performance evaluation; Finite-source retrial queues; Closed-form solutions; Orbital search; Block-structured Markov chain; MOSEL-2}, tags = {AutoI, DFG_MathMod, EuroNF, ResumeNet, MOSEL2}, url = {http://www.net.fim.uni-passau.de/pdf/Wuechner2009b.pdf}, web_url = {http://ami.ektf.hu/uploads/papers/finalpdf/AMI_36_from143to160.pdf}, web_url2 = {http://ami.ektf.hu/index.php?vol=36}, ISSN = {1787-5021 (Print); 1787-6117 (Online)}, author = {Wuechner, Patrick and Sztrik, Janos and De Meer, Hermann} } @Article { Hollick2008b, title = {Modeling of Self-Organizing Systems (Guest Editorial)}, journal = {Praxis der Informationsverarbeitung und Kommunikation (PIK)}, year = {2008}, volume = {31}, number = {1}, pages = {2--3}, abstract = {In the last decade, we witnessed the unparalleled success of communication networks such as the Internet or wireless mobile communication networks. The unprecedented scale of the aforementioned networks does not mark the end of the growth, but the emergence of wireless sensor networks and the ,,Internet of Things'' are going to further add to the complexity of today's communication networks. For providers and network operators to be able to plan, build, and maintain next generation networks, it is necessary to push the envelope of traditional means to control the network. From a user's perspective, the organic growth of autonomously operated (community) networks and of application-level overlay networks presents further challenges.}, note = {Editorial}, tags = {DFG_MathMod, EuroNF, EuroFGI, EuroFGI_MMSOS}, url = {http://www.net.fim.uni-passau.de/pdf/Hollick2008b.pdf}, web_url = {http://www.reference-global.com/doi/pdfplusdirect/10.1515/piko.2008.001}, ISSN = {0930-5157}, DOI = {10.1515/piko.2008.001}, author = {Hollick, Matthias and De Meer, Hermann and Schmitt, Jens B. and Wuechner, Patrick} } @Article { Wuechner2008a, title = {The Impact of Retrials on the Performance of Self-Organizing Systems}, journal = {Praxis der Informationsverarbeitung und Kommunikation (PIK)}, year = {2008}, volume = {31}, number = {1}, pages = {29--33}, abstract = {This article describes the application of the theory of retrial queues in capturing certain aspects of self-organizing behavior that arises, for example, in Peer-to-Peer networks. It can be shown that retrials have a fair effect on the performance of such self-organizing systems, and thus, should be taken into account adequately during the design and evaluation of these systems. Moreover, it can be shown that there is a notable difference between finite-source and infinite-source retrial queueing models. The main goal of this paper is to show the practical applicability of retrial queues and some of their varieties.}, tags = {AutoI, DFG_MathMod, EuroFGI, EuroFGI_MMSOS, EuroNF, ResumeNet, MOSEL2}, url = {http://www.net.fim.uni-passau.de/pdf/Wuechner2008a.pdf}, publisher = {K. G. Saur Verlag}, ISSN = {0930-5157}, DOI = {10.1515/piko.2008.006}, author = {Wuechner, Patrick and Sztrik, Janos and De Meer, Hermann} } @Article { DeMeer2006b, title = {{GI/ITG/MMB/KUVS} Fachgespraech Performance Modeling Of Self-Organizing Systems ({PMSOS'06})}, journal = {Praxis der Informationsverarbeitung und Kommunikation (PIK)}, year = {2006}, volume = {29}, number = {4}, pages = {258--262}, abstract = {Self-organization is expected to play a key architectural role for the future Internet as well as for large-scale pervasive computing systems such as wireless sensor networks. In conjunction with the ,,International Workshop on Self-Organizing Systems (IWSOS 2006)'', we organized the first ,,GI/ITG/MMB/KuVS Fachgespraech on Performance Modeling of Self-Organizing Systems (PMSOS'06)''. The event was hosted by the chair of Computer Networks \& Communications of Universitaet Passau. To make the Fachgespraech as attractive as possible, we introduced and trialed a novel dialogueintensifying format for discussions. In the aftermaths of the workshop, we have been able to collect evidence that the participants considered the workshop to be very vital and stimulating.}, tags = {EuroFGI, EuroNGI}, url = {http://www.net.fim.uni-passau.de/pdf/DeMeer2006b.pdf}, publisher = {K. G. Saur Verlag}, author = {De Meer, Hermann and Wuechner, Patrick and Schmitt, Jens B. and Hollick, Matthias} } @Article { Wuechner2006c, title = {A brief Introduction to {MOSEL-2}}, journal = {Transactions Automated Control Systems}, year = {2006}, volume = {1}, pages = {210--214}, abstract = {The versatile MOdeling, Specification and Evaluation Language is the core element of the MOSEL-2 tool. This description languages provides a high-level means for specifying models, performance measures, and the graphical presentation of results. The description languages is implemented in form of an evaluation environment that comprises translators to the modeling languages of several third-party performance evaluation tools that evaluate the specified model.}, tags = {EuroFGI, EuroNGI, MOSEL2}, url = {http://www.net.fim.uni-passau.de/pdf/Wuechner2006c.pdf}, publisher = {Publishing House Technical University}, address = {Tbilisi, Georgia}, organization = {Georgian Technical University}, ISSN = {1512-3979}, author = {Wuechner, Patrick and De Meer, Hermann and Barner, Joerg and Bolch, Gunter} } @Book { DeMeer2009a, title = {Performance Modeling of Computer Networks - Special Issue in Memory of Dr. Gunter Bolch}, year = {2009}, volume = {53}, number = {8}, abstract = {I am grateful for this opportunity to pay tribute to my dear friend and life-long mentor Dr. Gunter Bolch as a co-editor of this special issue in his memory. We were not only sharing common academic interests and writing scholarly books together but we were also sharing passions for such diverse activities as travelling and foreign cultures, cross-country skiing, or Jazz music. Gunter was very open minded, a beautifully moderate person, and a friend in its truest meaning. This special issue, however, is devoted to his academic passion of Performance Modeling, in general, and Queueing Networks, in particular. He has not only co-authored scholarly written books that have widely been cited and have gained world-wide acknowledgement, but many colleagues have taken pride in cooperation and joint publications with him during his overly productive life. Likewise, many of his students were motivated by his academic and personal spirit and followed up contributing in similar research areas. This special issue provides a collection of original contributions by former students of his and colleagues who have cooperated with him. While the contributions were solicited by invitation based on the relationship at least one author had with Gunter, all papers were thoroughly reviewed by at least three international reviewers each and subsequently carefully revised by the authors. As a result, we have been able to collect ten quality-assured papers as a witness to Gunter}, tags = {EuroNF, MOSEL2}, url = {http://www.net.fim.uni-passau.de/pdf/DeMeer2009a.pdf}, web_url = {http://www.sciencedirect.com/science/issue/6234-2009-999469991-1040194}, editor = {De Meer, Hermann and Wuechner, Patrick}, publisher = {Elsevier B.V.}, series = {Computer Networks (ComNet)}, ISSN = {1389-1286}, DOI = {10.1016/j.comnet.2009.03.001} } @Booklet { Wuechner2008d, title = {Queueing Networks and Markov Chains - 2nd Edition: Problems and Solutions}, year = {2008}, abstract = {In 2006, the second edition of our textbook on}, tags = {MOSEL2}, web_url = {http://www.net.fim.uni-passau.de/QNMC2/solutions/}, howpublished = {distributed by John Wiley \& Sons}, author = {Wuechner, Patrick and Auer, Christopher and Bolch, Gunter and De Meer, Hermann} } @Inproceedings { Casares-Giner2012a, title = {Combined Contention and {TDMA}-Based Communication in Wireless Sensor Networks}, year = {2012}, abstract = {Wireless sensor networks usually consist of a large number of very small, energy-constrained sensor nodes. The nodes capture information from their immediate environment to send it to a destination node (sink) in a timely manner. This work proposes a combined contention and TDMA-based approach for load balancing and a discrete-time Markov model that allows to study the trade-off between energy consumption and transfer delay in clustered wireless sensor networks. Our investigations show that the length of the TDMA frame needs to be configured close to the minimum that is capable of transferring the offered load for optimizing energy efficiency and minimizing the delay.}, keywords = {Wireless sensor networks; Clustering; Contention; TDMA; Energy; Delay; Queueing theory; Discrete-time Markov model}, tags = {EuroNF_PADU, EuroNF, EINS_NoE, Socionical}, url = {http://www.net.fim.uni-passau.de/pdf/Casares-Giner2012a.pdf}, web_url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6252158}, web_url2 = {http://www.bth.se/ngi2012}, publisher = {IEEE}, booktitle = {Proc. of the 8th Euro-NF Conf. on Next Generation Internet (NGI2012)}, DOI = {10.1109/NGI.2012.6252158}, author = {Casares-Giner, Vicente and Wuechner, Patrick and Pacheco-Paramo, Diego and De Meer, Hermann} } @Inproceedings { Wuechner2011a, title = {Modeling Wireless Sensor Networks Using Finite-Source Retrial Queues with Unreliable Orbit}, year = {2011}, volume = {6821}, pages = {73--86}, abstract = {Motivated by the need for performance models suitable for modeling and evaluation of wireless sensor networks, we introduce a retrial queueing system with a finite number of homogeneous sources, unreliable servers, orbital search, and unreliable orbit. All random variables involved in model construction are assumed to be independent and exponentially distributed. Providing a generalized stochastic Petri net model of the system, steady-state analysis of the underlying continuous-time Markov chain is performed and steady-state performance measures are computed by the help of the MOSEL-2 tool. The main novelty of this investigation is the introduction of an unreliable orbit and its application to wireless sensor networks. Numerical examples are derived to show the influence of sleep/awake time ratio, message dropping, and message blocking on the senor nodes' performance.}, note = {The original publication is available at www.springerlink.com}, keywords = {Performance evaluation; Unreliable finite-source retrial queue; Wireless sensor network; Energy efficiency; Self-organization}, tags = {DFG_MathMod, AutoI, ResumeNet, EuroNF, EuroNF_PADU, MOSEL2}, url = {http://www.net.fim.uni-passau.de/pdf/Wuechner2011a.pdf}, web_url = {http://perform.univie.ac.at/}, web_url2 = {http://www.springerlink.com/content/4851lv1w8822kh42/}, publisher = {Springer-Verlag}, series = {Lecture Notes in Computer Science (LNCS)}, booktitle = {Proc. of the Workshop on Performance Evaluation of Computer and Communication Systems (PERFORM 2010)}, DOI = {10.1007/978-3-642-25575-5_7}, author = {Wuechner, Patrick and Sztrik, Janos and De Meer, Hermann} } @Inproceedings { Kloch2010a, title = {Ad-Hoc information spread between mobile devices: a case study in analytical modeling of controlled self-organization in {IT} systems}, year = {2010}, volume = {5974}, pages = {101--112}, abstract = {We present an example of the use of analytical models to predict global properties of large-scale information technology systems from the parameters of simple local interactions. The example is intended as a first step towards using complex systems modeling methods to control self-organization in organic systems. It is motivated by a concrete application scenario of information distribution in emergency situations, but is relevant to other domains such as malware spread or social interactions. Specifically, we show how the spread of information through ad-hoc interactions between mobile devices depends on simple local interaction rules and parameters such as user mobility and physical interaction range. We show how three qualitatively different regimes of information 'infection rate' can be analytically derived and validate our model in extensive simulations.}, note = {The original publication is available at www.springerlink.com (2010)}, tags = {EuroNF, Socionical}, url = {http://www.net.fim.uni-passau.de/pdf/Kloch2010a.pdf}, web_url = {http://www.springerlink.com/content/a107535151856201/}, web_url2 = {http://www.sra.uni-hannover.de/arcs2010/}, publisher = {Springer-Verlag}, series = {Lecture Notes in Computer Science (LNCS)}, booktitle = {Proc. of 23rd Int'l Conf. on Architecture of Computing Systems (ARCS 2010)}, ISBN = {978-3-642-11949-1}, ISSN = {0302-9743 (Print); 1611-3349 (Online)}, DOI = {10.1007/978-3-642-11950-7}, author = {Kloch, Kamil and Kantelhardt, Jan W. and Lukowicz, Paul and Wuechner, Patrick and De Meer, Hermann} } @Inproceedings { Wuechner2010b, title = {Finite-Source Retrial Queues with Applications}, year = {2010}, volume = {2}, pages = {275--285}, abstract = {We consider a single-server retrial queueing system with a finite number of homogeneous sources generating requests after a random time. The service of an arriving customer finding the server idle starts immediately; otherwise the request enters into an orbit from where the calls are repeated after a random time. Upon completion of a service, with a certain probability the server searches for an orbiting customer. We assume the search time to be negligible. While modeling generation, retrial, and service times by their first two moments, we are interested in steady-state performance measures. The novelty of the investigation is the discussion of the second moment's effect on the performance of finite-source retrial queues with orbital search. The MOSEL-2 tool is used to formulate and solve the problem resulting in various illustrative numerical examples showing the effect of the moments and the search probability on the mean response time of the requests.}, keywords = {Retrial queueing systems; Finite number of sources; Orbital search; Performance tool; Performance measures; Hypoexponential distribution; Generalized exponential distribution}, tags = {EuroNF, Socionical, ResumeNet, DFG_MathMod}, url = {http://www.net.fim.uni-passau.de/pdf/Wuechner2010b.pdf}, web_url = {http://icai.ektf.hu/}, booktitle = {Proc. of the 8th Int'l Conf. on Applied Informatics}, author = {Wuechner, Patrick and Sztrik, Janos and De Meer, Hermann} } @Inproceedings { Paterok2010a, title = {In Memory of Dr. Gunter Bolch}, year = {2010}, volume = {5987}, pages = {3--7}, abstract = {The MMB Special Interest Group mourns for a highly valued member. Gunter Bolch died on May 29, 2008 in Erlangen, after a serious illness. He was very open minded, a beautifully moderate person, and a friend in its truest meaning. With MMB, he shared his academic passion of performance modelling, in general, and queueing networks, in particular.}, note = {The original publication is available at www.springerlink.com (2010)}, tags = {MOSEL2}, url = {http://www.net.fim.uni-passau.de/pdf/Paterok2010a.pdf}, web_url = {http://www.springerlink.com/content/60106m2v68842646/}, web_url2 = {http://www.mmb2010.org/}, publisher = {Springer-Verlag}, series = {Lecture Notes in Computer Science (LNCS)}, booktitle = {Proc. of the 15th Int'l GI/ITG Conf. on Measurement, Modelling and Evaluation of Computing Systems and Dependability and Fault Tolerance (MMB \& DFT 2010)}, ISBN = {978-3-642-12103-6}, DOI = {10.1007/978-3-642-12104-3_3}, author = {Paterok, Martin and De Meer, Hermann and Wuechner, Patrick} } @Inproceedings { Auer2009a, title = {Target-Oriented Self-Structuring in Classifying Cellular Automata}, year = {2009}, pages = {260--271}, abstract = {Some cellular automata are able to solve classification problems on their initial configuration by building globally visible structures. However, no formal measures exist yet for describing or detecting this behavior in general. The lack of such formal methods often leads to quite observer-dependent discussions of emergent computation. In this paper, we propose the measures of target orientation and self-structuring that allow to formally evaluate a cellular automaton's ability to solve a classification problem by emergent computation. By the means of these measures, globally emerging patterns can be recognized and their contribution to the solution of the classification problem can be judged in an observer-independent way.}, tags = {AutoI, EuroNF, ResumeNet, Socionical}, url = {http://www.net.fim.uni-passau.de/pdf/Auer2009a.pdf}, web_url = {http://www.mackenzie.br/fileadmin/automata/arquivos/Automata_2009_book_cover_and_initial_pages.pdf}, web_url2 = {http://www.mackenzie.br/automata2009.html}, publisher = {Mackenzie}, booktitle = {Proc. of the 15th Int'l Workshop on Cellular Automata and Discrete Complex Systems (Automata 2009)}, ISBN = {978-1-905986-21-7}, author = {Auer, Christopher and Wuechner, Patrick and De Meer, Hermann} } @Inproceedings { Auer2009b, title = {The Degree of Global-State Awareness in Self-Organizing Systems}, year = {2009}, volume = {5918}, pages = {125--136}, abstract = {Since the entities composing self-organizing systems have direct access only to information provided by their vicinity, it is a nontrivial task for them to determine properties of the global system state. However, this ability appears to be mandatory for certain self-organizing systems in order to achieve an intended functionality. Based on Shannon's information entropy, we introduce a formal measure that allows to determine the entities' degree of global-state awareness. Using this measure, self-organizing systems and suitable system settings can be identified that provide the necessary information to the entities for achieving the intended system functionality. Hence, the proposed degree supports the evaluation of functional properties during the design and management of self-organizing systems. We show this by applying the measure exemplarily to a self-organizing sensor network designed for intrusion detection. This allows us to find preferable system parameter settings.}, note = {The original publication is available at www.springerlink.com (2009)}, tags = {AutoI, EuroNF, ResumeNet, Socionical}, url = {http://www.net.fim.uni-passau.de/pdf/Auer2009b.pdf}, web_url = {http://www.springerlink.com/content/8410415t3u678xp8/}, publisher = {Springer-Verlag}, series = {Lecture Notes in Computer Science (LNCS)}, booktitle = {Proc. of the 4th Int'l Workshop on Self-Organizing Systems (IWSOS 2009)}, ISBN = {978-3-642-10864-8}, DOI = {10.1007/978-3-642-10865-5_11}, author = {Auer, Christopher and Wuechner, Patrick and De Meer, Hermann} } @Inproceedings { Auer2008a, title = {A Method to Derive Local Interaction Strategies for Improving Cooperation in Self-Organizing Systems}, year = {2008}, volume = {5343}, pages = {170--181}, abstract = {To achieve a preferred global behavior of self-organizing systems, suitable local interaction strategies have to be found. In general, this is a non-trivial task. In this paper, a general method is proposed that allows to systematically derive local interaction strategies by specifying the preferred global behavior. In addition, the resulting strategies can be evaluated using Markovian analysis. Then, by applying the proposed method exemplarily to the iterated prisoner}, note = {The original publication is available at www.springerlink.com (2008); received best-paper award}, tags = {AutoI, EuroNF, ResumeNet}, url = {http://www.net.fim.uni-passau.de/pdf/Auer2008a.pdf}, web_url = {http://www.springerlink.com/content/m15htn3460r3m194/}, web_url2 = {http://iwsos.ani.univie.ac.at/program.htm}, publisher = {Springer-Verlag}, series = {Lecture Notes in Computer Science (LNCS)}, booktitle = {Proc. of the 3rd Int'l Workshop on Self-Organizing Systems (IWSOS 2008)}, ISBN = {978-3-540-92156-1}, DOI = {10.1007/978-3-540-92157-8_15}, author = {Auer, Christopher and Wuechner, Patrick and De Meer, Hermann} } @Inproceedings { Wuechner2008c, title = {Homogeneous Finite-Source Retrial Queues with Search of Customers from the Orbit}, year = {2008}, pages = {109--124}, abstract = {We consider a retrial queueing system with a finite number of homogeneous sources of calls and a single server. Each source generates a request after an exponentially distributed time. An arriving customer finding the server idle enters into service immediately; otherwise the customer enters into an orbit. The service times are supposed to be exponentially distributed random variables. An orbiting customer competes for service, the inter-retrial times are exponentially distributed. Upon completion of a service, with a certain probability the server searches for an orbiting customer. Assuming the search time to be negligible, the source, service, and retrial times to be independent random variables, we perform the steady-state analysis of the model computing various steady-state performance measures and illustrative numerical examples are presented. The novelty of the investigation is the introduction of orbital search by the server for customers in finite-source retrial queues. The MOSEL-2 tool is used to formulate and solve the problem.}, keywords = {Retrial queueing systems; Finite number of sources; Orbital search; Performance tool; Performance measures}, tags = {DFG_MathMod, EuroNF, MOSEL2}, url = {http://www.net.fim.uni-passau.de/pdf/Wuechner2008c.pdf}, web_url = {http://www.mmb2008.org/}, publisher = {VDE Verlag}, booktitle = {Proc. of the 14th GI/ITG Conf. on Measurement, Modelling and Evaluation of Computer and Communication Systems (MMB 2008)}, ISBN = {978-3-8007-3090-2}, author = {Wuechner, Patrick and Sztrik, Janos and De Meer, Hermann} } @Inproceedings { Wuechner2008b, title = {Mathematical Design Models for Self-Organizing Systems}, year = {2008}, abstract = {Self-organization (SO) appears in many different fields: in computer science (e.g., sensor networks), biology (e.g., colony of ants), physics (e.g., elementary magnets), and many more. During the last years, engineering sciences have been attracted by the phenomenon of SO to overcome inevitable issues, for example, scalability issues that arise when engineering and managing large-scale systems consisting of numerous interacting entities. However, prior to engineering selforganizing systems (SOSs), a common terminology is needed to characterize and define SO and SO-related concepts.}, note = {Poster with Abstract}, tags = {AutoI, EuroNF, ResumeNet}, url = {http://www.net.fim.uni-passau.de/pdf/Wuechner2008b.pdf}, web_url = {http://iwsos.ani.univie.ac.at/download/wuechner_MathematicalDesignModelsForSelf-OrganizingSystems.pdf}, web_url2 = {http://www.iwsos.org/2008}, booktitle = {Supplementary online Proc. of the 3rd Int'l Workshop on Self-Organizing Systems (IWSOS 2008)}, author = {Wuechner, Patrick and Auer, Christopher and Holzer, Richard and De Meer, Hermann} } @Inproceedings { Wuechner2007b, title = {Mathematical Modeling of Self-Organizing Systems}, year = {2007}, abstract = {The evolution of the Internet reveals surprising turns and obstacles. Centralized approaches of introducing new services and architectures consistently failed to materialize at large scale. Quality of Service, group communication, and mobility support are only some examples for the difficulty with orchestrated approaches. The success story of the Internet, on the other hand, is strongly linked to decentralization. Robustness to failures or flexibility in introducing new applications such as the World Wide Web or Peer-to-Peer systems has been key momentum to technological advances and economics. Future networks are envisioned to be highly complex and difficult to manage due to heterogeneity of networks, spontaneous set-up of networks, and the envisioned number of interconnected devices, appliances, and artifacts. The concept of self-organization is widely spread in science among various disciplines. It has been applied successfully already in engineering and for describing the behavior of specific technical systems. Thus, self-organization is foreseen to play a major role in future communication systems.}, tags = {EuroFGI, EuroFGI_MMSOS}, url = {http://www.net.fim.uni-passau.de/pdf/Wuechner2007b.pdf}, web_url = {http://www3.informatik.uni-wuerzburg.de/ITG/2007/Abstracts/Abstract-Wuechner.pdf}, web_url2 = {http://www3.informatik.uni-wuerzburg.de/ITG/2007/Presentations/Presentation-Wuechner.pdf}, publisher = {University of Wuerzburg}, address = {Wuerzburg, Germany}, booktitle = {Proc. of the 7th Wuerzburg Workshop on IP: Joint EuroFGI and ITG Workshop on ,,Visions of Future Generation Networks'' (EuroView 2007)}, author = {Wuechner, Patrick and De Meer, Hermann} } @Inproceedings { Wuechner2007c, title = {Modeling Finite-Source Retrial Queueing Systems with Unreliable Heterogeneous Servers and Different Service Policies Using {MOSEL}}, year = {2007}, pages = {75--80}, abstract = {This paper deals with the performance analysis of multiple server retrial queueing systems with a finite number of homogeneous sources of calls, where the heterogeneous servers are subject to random breakdowns and repairs. The requests are serviced according to Random Selection and Fastest Free Server disciplines. The novelty of this investigation is the introduction of different service rates and different service policies together with the unreliability of the servers, which has essential influence on the performance of the system, and thus, it plays an important role in practical modeling of computer and communication systems. All random variables involved in the model construction are assumed to be exponentially distributed and independent of each other. The main steady-state performability measures are derived, and several numerical calculations are carried out by the help of the MOSEL tool (Modeling, Specification and Evaluation Language) under different service disciplines. The numerical results are graphically displayed to illustrate the effect of failure rates on the mean response time and on the overall system utilization.}, keywords = {Performance and Reliability Evaluation; Retrial Queuing System Model; Unreliable Heterogeneous Servers}, tags = {DFG_MathMod, EuroFGI, MOSEL2}, url = {http://www.net.fim.uni-passau.de/pdf/Wuechner2007c.pdf}, web_url = {http://www.net.fmi.uni-passau.de/hp/fileadmin/cnacc/dokus/pdf/conferences/Wuechner_ModelingFiniteSourceRetrial_ASMTA2007.pdf}, web_url2 = {http://www.comp.glam.ac.uk/ASMTA2007/index.html}, booktitle = {Proc. of the 14th Int'l Conf. on Analytical and Stochastic Modelling Techniques and Applications (ASMTA 2007)}, ISBN = {0-9553018-4-X (Print); 0-9553018-3-1 (CD)}, author = {Wuechner, Patrick and De Meer, Hermann and Bolch, Gunter and Roszik, Janos and Sztrik, Janos} } @Inproceedings { Wuechner2007a, title = {Structured Markov Chains Arising from Homogeneous Finite-Source Retrial Queues with Orbital Search}, year = {2007}, volume = {07461}, abstract = {We consider retrial queueing systems with a finite number of homogeneous sources of calls, a single reliable server, and the search for orbiting customers by the server after job completion. During this investigation, the infinitesimal generator of the underlying (finite) continuous-time Markov chain takes a (level-dependent) QBD-like form. After solving for the steady state probabilities using the MOSEL-2 tool, the results show a surprising maximum of the mean response time. This maximum was already discovered by other researchers dealing with finite-source retrial queues. However, to our best knowledge, no thorough investigation was done yet why this maximum exists and in which way it depends on the system parameters. In the talk, after introducing the backgrounds of finite-source retrial queues with orbital search, a generalized stochastic Petri net is used to derive the underlying continuous-time Markov chain and its generator. Finally, using the seminar, we can hopefully bring forward discussions how to make more general statements on the parameter-dependent behavior of the response time's maximum.}, tags = {DFG_MathMod, EuroFGI, EuroFGI_MMSOS, MOSEL2}, url = {http://www.net.fim.uni-passau.de/pdf/Wuechner2007a.pdf}, web_url = {http://drops.dagstuhl.de/opus/volltexte/2008/1389/}, web_url2 = {http://www.dagstuhl.de/Materials/Files/07/07461/07461.WuechnerPatrick.ExtAbstract.pdf}, publisher = {Schloss Dagstuhl, Leibniz-Zentrum fuer Informatik GmbH}, address = {Dagstuhl, Germany}, series = {Dagstuhl Seminar Proceedings}, booktitle = {Proc. of the Dagstuhl Seminar on Numerical Methods for Structured Markov Chains}, author = {Wuechner, Patrick and Sztrik, Janos and De Meer, Hermann} } @Inproceedings { Wuechner2006b, title = {A brief Introduction to {MOSEL-2}}, year = {2006}, pages = {473--476}, abstract = {The versatile MOdeling, Specification and Evaluation Language is the core element of the MOSEL-2 tool. This description languages provides a high-level means for specifying models, performance measures, and the graphical presentation of results. The description languages is implemented in form of an evaluation environment that comprises translators to the modeling languages of several third-party performance evaluation tools that evaluate the specified model.}, tags = {EuroFGI, EuroNGI, MOSEL2}, url = {http://www.net.fim.uni-passau.de/pdf/Wuechner2006b.pdf}, web_url = {http://www.mmb2006.org/}, publisher = {VDE Verlag}, booktitle = {Proc. of the 13th GI/ITG Conf. on Measurement, Modelling and Evaluation of Computer and Communication Systems (MMB 2006)}, organization = {GI/ITG/MMB, University of Erlangen}, ISBN = {978-3-8007-2945-6}, author = {Wuechner, Patrick and De Meer, Hermann and Barner, Joerg and Bolch, Gunter} } @Inproceedings { Wuechner2006a, title = {Discrete-Event System Performance Modeling of Self-Organizing Systems}, year = {2006}, pages = {14--18}, abstract = {The contribution of this paper is twofold. On the one hand the authors give a brief survey on existing publications on the performance modeling of discrete-event systems and on the existing literature on the modeling of self-organizing systems. On the other hand an evaluation is started towards answering the question if modeling techniques designed for discrete-event systems are capable of describing self-organizing systems. We demonstrate that self-organizing systems share many properties of discreteevent systems. Thus, the well-known methods developed for the performance investigation of discrete-event system performance seem to be attractive for the performance evaluation of self-organizing systems.}, note = {Technical Report MIP-0609}, tags = {EPSRC_P2POpt, EuroFGI, EuroNGI}, url = {http://www.net.fim.uni-passau.de/pdf/Wuechner2006a.pdf}, web_url = {http://www.fim.uni-passau.de/wissenschaftler/forschungsberichte.html}, publisher = {University of Passau}, booktitle = {Proc. of the Technical Discussion on Performance Modeling of Self-Organizing Systems (PMSOS 2006)}, author = {Wuechner, Patrick and De Meer, Hermann} } @Inproceedings { Wuechner2005a, title = {{MOSEL-2} - A Compact But Versatile Model Description Language And Its Evaluation Environment}, year = {2005}, abstract = {In this paper we present the current version of the MOdeling, Specification and Evaluation Language MOSEL-2 and show its applicability for performance and reliability modeling and evaluation of systems with Markovian and non-Markovian behavior. The tool MOSEL-2 consists of two major components: the description language and the evaluation environment. The description language is the core element of MOSEL-2 and provides a high-level means for specifying models, performance measures, and the graphical presentation of the results of these measures. MOSEL-2}, keywords = {MOSEL-2; Model description language; Evaluation environment; Performance modeling}, tags = {EuroNGI, MOSEL2}, url = {http://www.net.fim.uni-passau.de/pdf/Wuechner2005a.pdf}, publisher = {University of Hamburg}, booktitle = {Proc. of the Workshop MMBnet 2005}, author = {Wuechner, Patrick and De Meer, Hermann and Barner, Joerg and Bolch, Gunter} } @Inproceedings { Wuechner2004a, title = {Modelling a single {GSM/GPRS} cell with delay tolerant voice calls using {MOSEL-2}}, year = {2004}, pages = {88--94}, abstract = {In this paper we introduce the new version of the MOdelling, Specification and Evaluation Language}, keywords = {MOSEL-2; System description language; GSM/GPRS; DeTVoC; non-Markovian distributions; IGL}, tags = {MOSEL2}, url = {http://www.net.fim.uni-passau.de/pdf/Wuechner2004a.pdf}, web_url = {http://ducati.doc.ntu.ac.uk/uksim/uksim\%2704/Papers/Glamorgan-Bradford\%20papers/Wuchner-\%2004-08/paper04-08\%20CR.pdf}, booktitle = {Proc. of the 7th UK Simulation Conf. (UKSIM 2004)}, ISBN = {1-84233-099-3}, author = {Wuechner, Patrick and Al-Begain, Khalid and Barner, Joerg and Bolch, Gunter} } @Techreport { Bolch2006b, title = {Modeling Finite-Source Retrial Queueing Systems with Unreliable Heterogeneous Servers and Different Service Policies using {MOSEL}}, year = {2006}, number = {MIP-0611}, abstract = {This paper deals with the performance analysis of multiple server retrial queueing systems with a finite number of homogeneous sources of calls, where the heterogeneous servers are subject to random breakdowns and repairs. The requests are serviced according to Random Selection and Fastest Free Server disciplines. The novelty of this investigation is the introduction of different service rates and different service policies together with the unreliability of the servers, which has essential influence on the performance of the system, and thus it plays an important role in practical modeling of computer and communication systems. All random variables involved in the model construction are assumed to be exponentially distributed and independent of each other. The main steady-state performability measures are derived, and several numerical calculations are carried out by the help of the MOSEL tool (Modeling, Specification and Evaluation Language) under different service disciplines. The numerical results are graphically displayed to illustrate the effect of failure rates on the mean response time and on the overall system's utilization.}, tags = {DFG_MathMod, EPSRC_P2POpt, EuroFGI, EuroNGI, MOSEL2}, url = {http://www.net.fim.uni-passau.de/pdf/Bolch2006b.pdf}, web_url = {http://staff.fim.uni-passau.de/forschung/mip-berichte/MIP-0611.html}, web_url2 = {http://www.fim.uni-passau.de/wissenschaftler/forschungsberichte.html}, institution = {Faculty of Computer Science and Mathematics (FIM), University of Passau}, author = {Bolch, Gunter and Roszik, Janos and Sztrik, Janos and Wuechner, Patrick} } @Techreport { DeMeer2006c, title = {Self-Organizing Systems: New Trends in Architectures and Performance Modeling}, year = {2006}, number = {MIP-0609}, abstract = {Self-organization plays a key architectural role for the future Internet. Self-organization will enhance flexibility and evolvability of organically growing, large-scale distributed systems, e.g., of large-scale pervasive computing systems such as wireless sensor networks. These statements could be proved by the technical program of the IWSOS 2006. Sixteen high-quality papers were selected by a thorough review process out of more than 70 submissions from 21 different countries. The technical program of the IWSOS 2006 was particularly covering application-oriented topics like: the dynamics of structured and unstructured overlays; self-organization in grids, peer-to-peer networks, wireless environments, and autonomic computing; and the application of self-organization for enhancing network management and routing. The program of the IWSOS 2006 has been supplemented, besides the social events and tutorials, by a poster session on the role of ,,Self-Organization in European Next Generation Internet'' and also by a Technical Discussion on ,,Performance Modeling of Self-Organizing Systems''. The two parts of the technical report on hand is used to make the contributions to the poster session (Part I) and technical discussion (Part II) available to a broader community.}, note = {Supplementary Proc. of IWSOS/PMSOS}, tags = {EuroFGI, EuroNGI}, url = {http://www.net.fim.uni-passau.de/pdf/DeMeer2006c.pdf}, web_url = {http://staff.fim.uni-passau.de/forschung/mip-berichte/MIP-0609.html}, web_url2 = {http://www.fim.uni-passau.de/wissenschaftler/forschungsberichte.html}, institution = {Faculty of Computer Science and Mathematics (FIM), University of Passau}, author = {De Meer, Hermann and Wuechner, Patrick and Houyou, Amine M.} }