in a distributed network of processors sharing one indivisible memory page of size D. During runtime,

the processors access a unit of data from the page, and the system is allowed to migrate the page

between the processors. The problem is to compute (on-line) a schedule of page movements

to minimize the total communication cost.

The Dynamic Page Migration problem is an extension to the page migration.

It attempts to model the network dynamics, occurring, for example, in mobile networks.

However, the pace of changes is restricted, i.e. the distances between processors can

change only by a constant per round.

The movement of the nodes induce changes in the communication cost between each pair of nodes,

which is proportional to the distance between them raised to some power $alpha$.

This is typical for mobile wireless networks, where nodes can move with a constant speed,

and the cost of communication is measured in terms of energy used for sending the data.

Thus, by setting $alpha$ equal to the propagation exponent of the medium,

cost minimization becomes minimizing the total energy consumption in the system.

However, as proven in citedynamic-page-migration, if both network mobility and

request sequence are created by an adversary, then the competitive ratio is polynomially large in D and

in the number of the nodes. In our search for a reasonable, close-to-reality model, in this paper we

consider a scenario in which the network mobility is adversarial, but the requests are

generated randomly by a stochastic process. We design an algorithm MTFR for this scenario,

and prove that it is O(1)-competitive, on expectation and with high probability.}, author = {Bienkowski, Marcin}, booktitle = {Proc. of the 17th ACM Symposium on Parallelism in Algorithms and Architectures (SPAA 2005)}, location = {Las Vegas, Nevada, USA}, pages = {270--278}, publisher = {ACM Press, NY, USA}, title = {{Dynamic Page Migration with Stochastic Requests}}, year = {2005}, } @inproceedings{18912, abstract = {We consider Dynamic Page Migration (DPM) problem, one of the fundamental subproblems of data management in dynamically changing networks. We investigate a hybrid scenario, where access patterns to the shared object are dictated by an adversary, and each processor performs a random walk in X. We extend the previous results of [4]: we develop algorithms for the case where X is a ring, and prove that with high probability they achieve a competitive ratio of O~(min{D−−√4,n}), where D is the size of the shared object and n is the number of nodes in the network. These results hold also for any d-dimensional torus or mesh with diameter at least Ω~(D−−√).}, author = {Bienkowski, Marcin and Korzeniowski, Miroslaw}, booktitle = {Proc. of the European Conference in Parallel Processing (Euro-Par)}, isbn = {9783540287001}, issn = {0302-9743}, title = {{Dynamic Page Migration Under Brownian Motion}}, doi = {10.1007/11549468_105}, year = {2005}, } @inproceedings{18924, abstract = {Bluetooth is a wireless communication standard developed for personal area networks (PAN) that gained popularity in the last years. It was designed to connect a few devices together, however nowadays there is a need to build larger networks. Construction and maintenance algorithms have great effect on performance of the network. We present an algorithm based on Cube Connected Cycles (CCC) topology and show how to maintain the network so that it is easily scalable. Our design guarantees good properties such as constant degree and logarithmic dilation. Besides, the construction costs are proven to be at most constant times larger than any other algorithm would need.}, author = {Bienkowski, Marcin and Brinkmann, André and Korzeniowski, Miroslaw and Orhan, Orhan}, booktitle = {Proceedings of the 4th International Conference on Networking}, isbn = {9783540253396}, issn = {0302-9743}, pages = {413--420}, publisher = {Springer}, title = {{Cube Connected Cycles Based Bluetooth Scatternet Formation}}, doi = {10.1007/978-3-540-31956-6_49}, volume = {3420}, year = {2005}, } @phdthesis{19612, author = {Klein, Jan}, isbn = {3-939350-05-2}, title = {{Efficient Collision Detection for Point and Polygon Based Models}}, year = {2005}, } @article{15058, author = {Ziegler, Martin}, issn = {0304-3975}, journal = {Theoretical Computer Science}, pages = {14--26}, title = {{Stability versus speed in a computable algebraic model}}, doi = {10.1016/j.tcs.2005.09.053}, year = {2005}, } @inproceedings{17112, author = {Bienkowski, Marcin and Damerow, Valentina and Meyer auf der Heide, Friedhelm and Sohler, Christian}, booktitle = {Proceedings of the 21st European Workshop on Computational Geometry, Eindhoven, The Netherlands, March 9-11, 2005}, publisher = {Technische Universiteit Eindhoven}, title = {{Average case complexity of Voronoi diagrams of n sites from the unit cube}}, year = {2005}, } @inproceedings{17415, author = {Fischer, Matthias and Mueck, B. and Mahajan, K. and Kortenjan, M. and Laroque, C. and Dangelmaier, W.}, booktitle = {Proceedings of the Winter Simulation Conference}, isbn = {0780395190}, title = {{Multi-User Support and Motion Planning of Humans and Humans Driven Vehicles in Interactive 3D Material Flow Simulations}}, doi = {10.1109/wsc.2005.1574470}, year = {2005}, } @inbook{17989, author = {Meer, Klaus and Ziegler, Martin}, booktitle = {Fundamentals of Computation Theory}, isbn = {9783540281931}, issn = {0302-9743}, title = {{An Explicit Solution to Post’s Problem over the Reals}}, doi = {10.1007/11537311_41}, year = {2005}, } @inproceedings{18280, abstract = {The sometimes so-called Main Theorem of Recursive Analysis implies that any computable real function is necessarily continuous. We consider three relaxations of this common notion of real computability for the purpose of treating also discontinuous functions f:R->R:

*) non-deterministic computation;

*) relativized computation, specifically given access to oracles like 0' or 0'';

*) encoding input x and/or output y=f(x) in weaker ways according to the Real Arithmetic Hierarchy.

It turns out that, among these approaches, only the first one provides the required power.}, author = {Ziegler, Martin}, booktitle = {Proc. CiE 2005: New Computational Paradigms}, isbn = {9783540261797}, issn = {0302-9743}, pages = {562--571}, publisher = {Springer}, title = {{Computability and Continuity on the Real Arithmetic Hierarchy and the Power of Type-2 Nondeterminism}}, doi = {10.1007/11494645_68}, volume = {3526}, year = {2005}, } @inproceedings{18449, author = {Loeser, Christoph and Drüke, Isabell and Oesterdiekhoff, Brigitte}, booktitle = {IEEE International Conference on Industrial Informatics (INDIN)}, title = {{ Glaschick, Rainer: Integrative Approach of Web Services and Universal Plug and Play within an AV Scenario}}, year = {2005}, } @article{18855, abstract = {We consider the problem of computing the weight of a Euclidean minimum spanning tree for a set of n points in $\mathbb R^d$. We focus on the setting where the input point set is supported by certain basic (and commonly used) geometric data structures that can provide efficient access to the input in a structured way. We present an algorithm that estimates with high probability the weight of a Euclidean minimum spanning tree of a set of points to within $1 + \eps$ using only $\widetilde{\O}(\sqrt{n} \, \text{poly} (1/\eps))$ queries for constant d. The algorithm assumes that the input is supported by a minimal bounding cube enclosing it, by orthogonal range queries, and by cone approximate nearest neighbor queries. Read More: https://epubs.siam.org/doi/10.1137/S0097539703435297 }, author = {Czumaj, Artur and Ergün, Funda and Fortnow, Lance and Magen, Avner and Newman, Ilan and Rubinfeld, Ronitt and Sohler, Christian}, issn = {0097-5397}, journal = {SIAM Journal on Computing}, number = {1}, pages = {91--109}, title = {{Approximating the Weight of the Euclidean Minimum Spanning Tree in Sublinear Time}}, doi = {10.1137/s0097539703435297}, volume = {35}, year = {2005}, } @inproceedings{18867, abstract = {Modern computer graphics systems are able to render sophisticated 3D szenes consisting of millions of polygons. In this paper we address the problem of occlusion culling. Aila, Miettinen, and Nordlund suggested to implement a FIFO buffer on graphics cards which is able to delay the polygons before drawing them. When one of the polygons within the buffer is occluded or masked by another polygon arriving later from the application, the rendering engine can drop the occluded one without rendering, saving important rendering time.

We introduce a theoretical online model to analyse these problems in theory using competitive analysis. For different cost measures addressed we invent the first competitive algorithms for online occlusion culling. Our implementation shows that these algorithms outperform known ones for real 3D scenes as well.}, author = {Frahling, Gereon and Krokowski, Jens}, booktitle = {Proc. of the 13th Annual European Symposium on Algorithms (ESA 2005)}, isbn = {9783540291183}, issn = {0302-9743}, pages = {758--769}, publisher = {Springer}, title = {{Online Occlusion Culling}}, doi = {10.1007/11561071_67}, volume = {3669}, year = {2005}, } @inproceedings{18925, abstract = {The dynamic page migration problem citedynamic-page-migration is defined in

a distributed network of $n$ mobile nodes sharing one indivisible memory page

of size $D$. During runtime, the nodes can both access a unit of data from

the page and move with a constant speed, thus changing the costs of communication.

The problem is to compute

to minimize the total communication cost.

In this paper we construct and analyze the first deterministic algorithm for this problem.

We prove that it achieves an (up to a constant factor) optimal competitive ratio

$O(n cdot sqrtD)$. We show that the randomization of this algorithm

improves this ratio to $O(sqrtD cdot log n)$ (against an oblivious adversary).

This substantially improves an $O(n cdot sqrtD)$ upper bound from citedynamic-page-migration.

We also give an almost matching lower bound of $Omega(sqrtD cdot sqrtlog n)$ for this problem.}, author = {Bienkowski, Marcin and Dynia, Miroslaw and Korzeniowski, Miroslaw}, booktitle = {Proc. of the 22nd Symposium on Theoretical Aspects of Computer Science (STACS)}, isbn = {9783540249986}, issn = {0302-9743}, pages = {365--376}, title = {{Improved Algorithms for Dynamic Page Migration}}, doi = {10.1007/978-3-540-31856-9_30}, year = {2005}, } @inbook{16468, author = {Bienkowski, Marcin and Korzeniowski, Miroslaw and Meyer auf der Heide, Friedhelm}, booktitle = {Peer-to-Peer Systems IV}, isbn = {9783540290681}, issn = {0302-9743}, title = {{Dynamic Load Balancing in Distributed Hash Tables}}, doi = {10.1007/11558989_20}, year = {2005}, } @proceedings{17113, editor = {Leonardi, Stefano and Meyer auf der Heide, Friedhelm and Wagner, Dorothea}, location = {Schloss Dagstuhl, Germany}, title = {{Abstracts Collection -- Algorithmic Aspects of Large and Complex Networks}}, volume = {05361}, year = {2005}, } @inproceedings{16470, abstract = {We present a web computing library (PUBWCL) in Java that allows to execute strongly coupled, massively parallel algorithms in the bulk-synchronous (BSP) style on PCs distributed over the internet whose owners are willing to donate their unused computation power. PUBWCL is realized as a peer-to-peer system and features migration and restoration of BSP processes executed on it. The use of Java guarantees a high level of security and makes PUBWCL platform independent. In order to estimate the loss of efficiency inherent in such a Java-based system, we have compared it to our C-based PUB-Library. }, author = {Bonorden, Olaf and Gehweiler, Joachim and Meyer auf der Heide, Friedhelm}, booktitle = {Proceeedings of 6th International Conference on Parallel Processing and Applied Mathematics (PPAM)}, isbn = {9783540341413}, issn = {0302-9743}, pages = {801--808}, title = {{A Web Computing Environment for Parallel Algorithms in Java}}, doi = {10.1007/11752578_96}, year = {2005}, } @inbook{16469, author = {Bienkowski, Marcin and Meyer auf der Heide, Friedhelm}, booktitle = {Mathematical Foundations of Computer Science 2005}, isbn = {9783540287025}, issn = {0302-9743}, title = {{Page Migration in Dynamic Networks}}, doi = {10.1007/11549345_1}, year = {2005}, } @article{18282, author = {Ziegler, Martin}, issn = {0020-7748}, journal = {International Journal of Theoretical Physics}, number = {11}, pages = {2059--2071}, title = {{Computational Power of Infinite Quantum Parallelism}}, doi = {10.1007/s10773-005-8984-0}, volume = {44}, year = {2005}, } @article{18763, abstract = {Property testing is a relaxation of classical decision problems which aims at distinguishing between functions having a predetermined property and functions being far from any function having the property. In this paper we present a novel framework for analyzing property testing algorithms. Our framework is based on a connection of property testing and a new class of problems which we call abstract combinatorial programs . We show that if the problem of testing a property can be reduced to an abstract combinatorial program of small dimension , then the property has an efficient tester. We apply our framework to a variety of problems. We present efficient property testing algorithms for geometric clustering problems, for the reversal distance problem, and for graph and hypergraph coloring problems. We also prove that, informally, any hereditary graph property can be efficiently tested if and only if it can be reduced to an abstract combinatorial program of small size. Our framework allows us to analyze all our testers in a unified way, and the obtained complexity bounds either match or improve the previously known bounds. Furthermore, even if the asymptotic complexity of the testers is not improved, the obtained proofs are significantly simpler than the previous ones. We believe that our framework will help to understand the structure of efficiently testable properties.}, author = {Czumaj, Artur and Sohler, Christian}, issn = {0097-5397}, journal = {SIAM Journal on Computing}, number = {3}, pages = {580--615}, title = {{Abstract Combinatorial Programs and Efficient Property Testers}}, doi = {10.1137/s009753970444199x}, volume = {34}, year = {2005}, } @inproceedings{18768, author = {Bădoiu, Mihai and Czumaj, Artur and Indyk, Piotr and Sohler, Christian}, booktitle = {Proc. of the 32nd International Colloquium on Automata, Languages and Programming (ICALP)}, isbn = {9783540275800}, issn = {0302-9743}, pages = {866--877}, title = {{Facility Location in Sublinear Time}}, doi = {10.1007/11523468_70}, year = {2005}, } @inproceedings{18787, abstract = {A dynamic geometric data stream consists of a sequence of m insert/delete operations of points from the discrete space {1,..., ∆} d [26]. We develop streaming (1 + ɛ)-approximation algorithms for k-median, k-means, MaxCut, maximum weighted matching (MaxWM), maximum travelling salesperson (MaxTSP), maximum spanning tree (MaxST), and average distance over dynamic geometric data streams. Our algorithms maintain a small weighted set of points (a coreset) that approximates with probability 2/3 the current point set with respect to the considered problem during the m insert/delete operations of the data stream. They use poly(ɛ −1, log m, log ∆) space and update time per insert/delete operation for constant k and dimension d. Having a coreset one only needs a fast approximation algorithm for the weighted problem to compute a solution quickly. In fact, even an exponential algorithm is sometimes feasible as its running time may still be polynomial in n. For example one can compute in poly(log n, exp(O((1+log(1/ɛ)/ɛ) d−1))) time a solution to k-median and k-means [21] where n is the size of the current point set and k and d are constants. Finding an implicit solution to MaxCut can be done in poly(log n, exp((1/ɛ) O(1))) time. For MaxST and average distance we require poly(log n, ɛ −1) time and for MaxWM we require O(n 3) time to do this.}, author = {Sohler, Christian and Frahling, Gereon}, booktitle = {Proceedings of the 37th ACM Symposium on Theory of Computing (STOC)}, pages = {209--217}, title = {{Coresets in Dynamic Geometric Data Streams}}, year = {2005}, } @inproceedings{18915, abstract = {We present a simple two-person Bucket Game, based on throwing balls into buckets, and we

discuss possible players' strategies.

We use these strategies to create an approximation algorithm for a generalization of

the well known Set Cover problem, where we need to cover each element by at least $k$ sets.

Furthermore, we apply these strategies to construct a randomized algorithm for Dynamic Page Migration

problem achieving the optimal competitive ratio against an oblivious adversary.}, author = {Bienkowski, Marcin and Byrka, Jarosław}, booktitle = {Proc. of the 13th Annual European Symposium on Algorithms (ESA 2005)}, isbn = {9783540291183}, issn = {0302-9743}, pages = {815--826}, publisher = {Springer }, title = {{Bucket Game with Applications to Set Multicover and Dynamic Page Migration}}, doi = {10.1007/11561071_72}, volume = {3669}, year = {2005}, } @inproceedings{16471, abstract = {We compare different load balancing strategies for Bulk-Synchronous Parallel (BSP) programs in a web computing environment. In order to handle the influence of the fluctuating available computation power, we classify the external work load. We evaluate the load balancing algorithms using our web computing library for BSP programs in Java (PUBWCL). Thereby we simulated the external work load in order to have repeatable testing conditions. With the best performing load balancing strategy we could save 39% of the execution time averaged and even up to 50% in particular cases.}, author = {Bonorden, Olaf and Gehweiler, Joachim and Meyer auf der Heide, Friedhelm}, booktitle = {Proceeedings of 6th International Conference on Parallel Processing and Applied Mathematics (PPAM)}, isbn = {9783540341413}, issn = {0302-9743}, pages = {839--846}, title = {{Load Balancing Strategies in a Web Computing Environment}}, doi = {10.1007/11752578_101}, year = {2005}, } @phdthesis{18910, author = {Bienkowski, Marcin}, isbn = {978-3-942647-01-4}, title = {{Page migration in dynamic networks}}, year = {2005}, } @phdthesis{17413, author = {Fischer, Matthias}, title = {{Design, analysis, and evaluation of a data structure for distributed virtual environments}}, year = {2005}, } @article{18790, author = {Czumaj, Artur and Sohler, Christian}, issn = {0304-3975}, journal = {Theoretical Computer Science}, number = {1}, pages = {37--52}, title = {{Testing hypergraph colorability}}, doi = {10.1016/j.tcs.2004.09.031}, volume = {331}, year = {2005}, } @phdthesis{19611, author = {Volbert, Klaus}, isbn = {3-935433-77-8}, title = {{Geometric Spanners for Topology Control in Wireless Networks}}, year = {2005}, } @inproceedings{16480, author = {Leonardi, S. and Marchetti-Spaccamela, A. and Meyer auf der Heide, Friedhelm}, booktitle = {SPAA '04: Proceedings of the sixteenth annual ACM symposium on Parallelism in algorithms and architectures}, isbn = {1581138407}, title = {{Scheduling against an adversarial network}}, doi = {10.1145/1007912.1007936}, year = {2004}, } @inproceedings{18448, author = {Oesterdiekhoff, Brigitte}, booktitle = {Proceedings of IFIP Working Conference on Distributed and Parallel Embedded Systems (DIPES'04)}, title = {{Internet Premium Services for Flexible Format Distributed Devices}}, year = {2004}, } @inproceedings{18777, author = {Sohler, Christian and Damerow, Valentina}, booktitle = {Proceedings of the 20th European Workshop on Computational Geometry (EWCG'04)}, pages = {93 -- 96}, title = {{Smoothed Number of Extreme Points under Uniform Noise}}, year = {2004}, } @inproceedings{16474, abstract = {Given n distinct points p1, p2, ... , pn in the plane, the map labeling problem with four squares is to place n axis-parallel equi-sized squares Q1, ... ,Qn of maximum possible size such that pi is a corner of Qi and no two squares overlap. This problem is NP-hard and no algorithm with approximation ratio better than 1/2 exists unless P = NP [10]. In this paper, we consider a scenario where we want to visualize the information gathered by smart dust, i.e. by a large set of simple devices, each consisting of a sensor and a sender that can gather sensor data and send it to a central station. Our task is to label (the positions of) these sensors in a way described by the labeling problem above. Since these devices are not positioned accurately (for example, they might be dropped from an airplane), this gives rise to consider the map labeling problem under the assumption, that the positions of the points are not fixed precisely, but perturbed by random noise. In other words, we consider the smoothed complexity of the map labeling problem. We present an algorithm that, under such an assumption and Gaussian random noise with sufficiently large variance, has linear smoothed complexity.}, author = {Bansal, Vikas and Meyer auf der Heide, Friedhelm and Sohler, Christian}, booktitle = {12th Annual European Symposium on Algorithms (ESA 2004)}, isbn = {9783540230250}, issn = {0302-9743}, title = {{Labeling Smart Dust}}, doi = {10.1007/978-3-540-30140-0_9}, volume = {3221}, year = {2004}, } @inproceedings{18778, abstract = {Given a point set P in the d-dimensional unit hypercube, we give upper bounds on the maximal expected number of extreme points when each point is perturbed by small random noise chosen independently for each point from the same noise distribution Δ. Our results are parametrized by the variance of the noise distribution. For large variance we essentially consider the average case for distribution Δ while for variance 0 we consider the worst case. Hence our results give upper bounds on the number of extreme points where our input distributions range from average case to worst case.

Our main contribution is a rather general lemma that can be used to obtain upper bounds on the expected number of extreme points for a large class of noise distributions. We then apply this lemma to obtain explicit bounds for random noise coming from the Gaussian normal distribution of variance σ² and the uniform distribution in a hypercube of side length &epsilon. For these noise distributions we show upper bounds of O( (1/ σ )^d * log^3/2 * d - 1 n ) and O( ( (n log n) / ε )^d/(d+1) ), respectively. Besides its theoretical motivation our model is also motivated by the observation that in many applications of convex hull algorithms the input data is inherently noisy, e.g. when the data comes from physical measurement or imprecise arithmetic is used.}, author = {Damerow, Valentina and Sohler, Christian}, booktitle = {Proceedings of the 12th European Symposium on Algorithms (ESA'04)}, isbn = {9783540230250}, issn = {0302-9743}, title = {{Extreme Points Under Random Noise}}, doi = {10.1007/978-3-540-30140-0_25}, year = {2004}, } @inproceedings{18785, abstract = {A limiting factor in the performance of a render- ing system is the number of state changes, i.e., changes of the attributes material, texture, shader program, etc., in the stream of rendered primitives. We propose to include a small buffer between appli- cation and graphics hardware in the rendering sys- tem. This pipeline buffer is used to rearrange the incoming sequence of primitives on-line and locally in such a way that the number of state changes is minimized. This method is generic; it can be easily integrated into existing rendering systems. In our experiments a pipeline buffer reduces the number of state changes by an order of magnitude and achieves almost the same rendering time as an optimal, i.e., presorted, sequence without pipeline buffer. Due to its simple structure and its low mem- ory requirements this method can easily be imple- mented in software or even hardware.}, author = {Sohler, Christian and Krokowski, Jens and Räcke, Harald and Westermann, Matthias}, booktitle = {Proceedings of the Vision, Modeling, and Visualization Conference (VMV 2004)}, title = {{Reducing State Changes with a Pipeline Buffer}}, year = {2004}, } @inproceedings{16475, author = {Bienkowski, Marcin and Korzeniowski, Miroslaw and Meyer auf der Heide, Friedhelm}, booktitle = {Proceedings of the sixteenth annual ACM symposium on Parallelism in algorithms and architectures - SPAA '04}, isbn = {1581138407}, title = {{Fighting against two adversaries}}, doi = {10.1145/1007912.1007923}, year = {2004}, } @inproceedings{17346, author = {Brinkmann, André and Heidebuer, Michael and Meyer auf der Heide, Friedhelm and Rückert, Ulrich and Salzwedel, Kay and Vodisek, Mario}, booktitle = {21st {IEEE} Conference on Mass Storage Systems and Technologies / 12th {NASA} Goddard Conference on Mass Storage Systems and Technologies, Greenbelt, Maryland, USA}, editor = {Kobler, Ben and Hariharan, P. C.}, pages = {153----157}, publisher = {IEEE}, title = {{V:Drive - Costs and Benefits of an Out-of-Band Storage Virtualization System}}, year = {2004}, } @inproceedings{18279, abstract = {For $c in REAL$, a $c$-spanner is a subgraph of a complete Euclidean graph satisfying that between any two vertices there exists a path of weighted length at most $c$ times their geometric distance. Based on this property to approximate a complete weighted graph, sparse spanners have found many applications, e.g., in FPTAS, geometric searching, and radio networks. For geometric searching, it turned out to suffice whether the radius rather than the length of some path between any two vertices is bounded relatively to their geometric distance; this is the defining property of weak spanners. Finally regarding radio network applications, a power spanner accounts for the total energy afforded for a wireless transmission with the requirement that the sum of the squares of the lengths of some path between any two planar vertices must be bounded relatively to the square of their geometric distance (or higher powers up to 6 or even 8).

While it is known that any $c$-spanner is also both a weak $C_1$-spanner and a $C_2$-power spanner (for appropriate $C_1,C_2$ depending only on $c$ but not on the graph under consideration), we show that the converse fails: There exists a family of $c_1$-power spanners that are no weak $C$-spanners and also a family of weak $c_2$-spanners that are no $C$-spanners for any fixed $C$ (and thus no uniform spanners, either). However the deepest result of the present work reveals that, surprisingly, any weak spanner is also a uniform power spanner. We further generalize the latter notion by considering $(c,delta)$-power spanners where the sum of the $delta$-th powers of the lengths has to be bounded; so $(cdot,2)$-power spanners coincide with the usual power spanners and $(cdot,1)$-power spanners are classical spanners. Interestingly, these $(cdot,delta)$-power spanners form a strict hierarchy where the above results still hold for any $deltageq2$; some even hold for $delta>1$ while counterexamples reveal others to fail for $delta<2$. In fact we show that in general every self-similar curve of fractal dimension $d>delta$ is no $(C,delta)$-power spanner for any fixed $C$. }, author = {Schindelhauer, Christian and Volbert, Klaus and Ziegler, Martin}, booktitle = {Proc. of 15th Annual International Symposium on Algorithms and Computation (ISAAC'04)}, isbn = {9783540241317}, issn = {0302-9743}, pages = {805--821}, publisher = {Springer }, title = {{Spanners, Weak Spanners, and Power Spanners for Wireless Networks}}, doi = {10.1007/978-3-540-30551-4_69}, volume = {3341}, year = {2004}, } @inproceedings{18786, author = {Sohler, Christian and Czumaj, Artur}, booktitle = {Automata, Languages and Programming (ICALP)}, number = {1}, pages = {396--407}, title = {{Sublinear-Time Approximation for Clustering via Random Sampling}}, year = {2004}, } @inproceedings{18263, abstract = {We generalize univariate multipoint evaluation of polynomials of degree n at sublinear amortized cost per point. More precisely, it is shown how to evaluate a bivariate polynomial p of maximum degree less than n, specified by its n^2 coefficients, simultaneously at n^2 given points using a total of O(n^2.667) arithmetic operations. In terms of the input size N being quadratic in n, this amounts to an amortized cost of O(N^0.334) per point.}, author = {Nüsken, Michael and Ziegler, Martin}, booktitle = {Proc. 12th Annual Symposium on Algorithms (ESA'04)}, isbn = {9783540230250}, issn = {0302-9743}, pages = {544--555}, publisher = {Springer}, title = {{Fast Multipoint Evaluation of Bivariate Polynomials}}, doi = {10.1007/978-3-540-30140-0_49}, volume = {3221}, year = {2004}, } @article{17986, author = {Ziegler, Martin and Brattka, Vasco}, journal = {Theoretical Computer Science}, number = {1-3}, pages = {187--211}, title = {{Computability in linear algebra}}, doi = {https://doi.org/10.1016/j.tcs.2004.06.022}, volume = {326}, year = {2004}, } @article{16399, abstract = {We present a new data structure for rendering highly complex virtual environments of arbitrary topology. The special feature of our approach is that it allows an interactive navigation in very large scenes (30 GB/400 million polygons in our benchmark scenes) that cannot be stored in main memory, but only on a local or remote hard disk. Furthermore, it allows interactive rendering of substantially more complex scenes by instantiating objects. The sampling process is done in the preprocessing. There, the polygons are randomly distributed in our hierarchical data structure, the randomized sample tree. This tree only uses space that is linear in the number of polygons. In order to produce an approximate image of the scene, the tree is traversed and polygons stored in the visited nodes are rendered. During the interactive walkthrough, parts of the sample tree are loaded from local or remote hard disk. We implemented our algorithm in a prototypical walkthrough system. Analysis and experiments show that the quality of our images is comparable to images computed by the conventional z-buffer algorithm regardless of the scene topology.}, author = {Klein, Jan and Krokowski, Jens and Fischer, Matthias and Wand, Michael and Wanka, Rolf and Meyer auf der Heide, Friedhelm}, issn = {1054-7460}, journal = {Presence: Teleoperators and Virtual Environments}, pages = {617--637}, title = {{The Randomized Sample Tree: A Data Structure for Interactive Walk-Throughs in Externally Stored Virtual Environments}}, doi = {10.1162/1054746043280619}, year = {2004}, } @inproceedings{18364, abstract = {The visualisation of manufacturing-processes assists the user in understanding and analysis. Typically he can move free and unguided in a virtual environment which visualizes the entire process. Thus knowledge and conclusions are to some extend acquired on a random base. This article describes the development of a tool, which enables the user to interactively improve significant production processes in the simulation. He moves in a virtual 3D-environment (walkthrough system) and is able to acquire automatically calculated indications for significant processes. At the same time the simulation considers significant objects in a more detailed way. If the viewer is interested in a significant process, he is automatically guided to the relevant location where he can examine the critical situation by modification of the simulation model.}, author = {Mueck, Bengt and Dangelmaier, Wilhelm and Laroque, Christoph and Fischer, Matthias and Kortenjan, Michael}, booktitle = {Simulation and Visualisation 2004}, pages = {73--83}, publisher = {SCS European Publishing House}, title = {{Guidance of Users in Interactive 3D-Visualisations of Material Flow Simulations}}, year = {2004}, } @article{16477, author = {Meyer auf der Heide, Friedhelm and Schindelhauer, Christian and Volbert, Klaus and Grünewald, Matthias}, issn = {1432-4350}, journal = {Theory of Computing Systems}, pages = {343--370}, title = {{Congestion, Dilation, and Energy in Radio Networks}}, doi = {10.1007/s00224-004-1124-z}, year = {2004}, } @article{18447, author = {Oesterdiekhoff, Brigitte}, journal = {Informatik Spektrum}, number = {5}, pages = {448--452}, title = {{Transcoding von Webinhalten}}, volume = {27}, year = {2004}, } @phdthesis{19616, author = {Salzwedel, Kay}, isbn = {3-935433-62-X}, title = {{Data Distribution Algorithms for Storage Networks}}, year = {2004}, }