31 M. Lopez V. Rodriguez W.T. Tsai D. Volovik 1986 IEEE 10th International Computer Software and Applications Conference 240-246 31 M. Lopez S. Sahni R. Janardan 1993 IEEE/ACM International Conference on Computer-Aided Design 31 S.T. Leutenegger D. Dias 1993 ACM SIGMOD 1993 The TPC-C benchmark is a new benchmark approved by the TPC council intended for comparing database platforms running a medium complexity transaction processing workload. Some key aspects in which this new benchmark differs from the TPC-A benchmark are in having several transaction types, some of which are more complex than that in TPC-A, and in having data access skew. In this paper we present results from a modelling study of the TPC-C benchmark for both single node and distributed database management systems. We simulate the TPC-C workload to determine expected buffer miss rates assuming an LRU buffer management policy. These miss rates are then used as inputs to a throughput model. From these models we show the following: (i) We quantify the data access skew as specified in the benchmark and show what fraction of the accesses go to what fraction of the data. (ii) We quantify the resulting buffer hit ratios for each relation as a function of buffer size. (iii) We show that close to linear scale-up (about 3\% from the ideal) can be achieved in a distributed system, assuming replication of a read-only table. (iv) We examine the effect of packing hot tuples into pages and show that significant price/performance benefit can be thus achieved. (v) Finally, by coupling the buffer simulations with the throughput model, we examine typical disk/memory configurations that maximize the overall price/performance. 0 M. Lopez R. Janardan 1993 International Journal of Computational Geometry and Applications 3 1 39-69 31 M. Lopez P. Breznay 1993 International Conference on Parallel Processing 307-310 31 M. Lopez P. Breznay 1994 International Conference on Parallel Processing 59-62 31 G. Horton S.T. Leutenegger 1994 ACM SIGMETRICS 94 A new iterative algorithm, the {\em multi-level} algorithm, for the numerical solution of steady state Markov chains is presented. The method utilizes a set of recursively coarsened representations of the original system to achieve accelerated convergence. It is motivated by multigrid methods, which are widely used for fast solution of partial differential equations. Initial results of numerical experiments are reported, showing significant reductions in computation time, often an order of magnitude or more, relative to the Gauss-Seidel and optimal SOR algorithms for a variety of test problems. It is shown how the well-known iterative aggregation-disaggregation algorithm of Takahashi can be interpreted as a special case of the new method. 31 A. Brunstrom S.T. Leutenegger R. Simha 1995 Fourth International Conference on Information and Knowledge Management, November 1995 (CKIM 95) Traditionally, allocation of data in distributed database management systems has been determined by off-line analysis and optimization. This technique works well for static database access patterns, but is often inadequate for frequently changing workloads. This paper addresses the problem of dynamically reallocating data in a partionable distributed database with changing access patterns. Rather than complicated and expensive optimization algorithms, a simple heuristic is presented and shown, via an implementation study, to improve system throughput by 30% in a local area network based system. For a wide area network the performance gain is expected to be even larger. It is also shown that individual site load must be taken into consideration when reallocating data. A a simple policy that incorporates load in the reallocation decision is provided. 31 R. Thurimella M. Lopez 1995 597-601 http://www.cs.du.edu/~ramki/papers/cc.pdf 0 M. Lopez R. Thurimella 1995 IEEE Transactions on Computers 44 4 593-601 31 S.T. Leutenegger G. Horton 1995 Second Int Workshop on the Numerical Solution of Markov Chains Recently the Multi-Level algorithm was introduced as a general purpose solver for the solution of steady state Markov chains. In this paper we consider the performance of the Multi-Level algorithm for solving Nearly Completely Decomposable (NCD) Markov chains, for which special-purpose iterative aggregation/disaggregation algorithms such as the Koury-McAllister-Stewart (KMS) method have been developed that can exploit the decomposability of the the Markov chain. We present experimental results indicating that the general-purpose Multi-Level algorithm is competitive, and can be significantly faster than the special-purpose KMS algorithm when Gauss-Seidel and Gaussian Elimination are used for solving the individual blocks. 0 S.T. Leutenegger M.A. Lopez 1996 ACM SIGMETRICS 0 M. Lopez S. Sahni R. Janardan 1996 IEEE Transactions on Computer Aided Design 15 9 1151-1159 0 M. Lopez D. Mehta 1996 ACM Trans. on Design Automation of Electronic Systems 1 3 371-395 0 S.T. Leutenegger D.M. Nicol 1997 IEEE Transactions on Knowledge and Data Engineering 9 3 This paper considers the problem of bulk-loading large data sets for for the gridfile multi-attribute indexing technique. We propose a rectilinear partitioning algorithm that heuristically seeks to minimize the size of the gridfile needed to ensure no bucket overflows. Empirical studies on both synthetic data sets and on data sets drawn from computational fluid dynamics applications demonstrate that our algorithm is very efficient, and is able to handle large data sets. In addition, we present an algorithm for bulk-loading data sets too large to fit in main memory. Utilizing a sort of the entire data set it creates a gridfile without incurring any overflows. 0 S.T. Leutenegger X.H. Sun 1997 Journal of Parallel and Distributed Computing (JPDC) The low cost and availability of clusters of workstations have lead researchers to re-explore distributed computing using independent workstations. This approach may provide better cost/performance than tightly coupled multiprocessors. In practice, this approach often utilizes wasted cycles to run parallel jobs. In this paper we address the feasibility of such a non-dedicated parallel processing environment assuming workstation processes have preemptive priority over parallel tasks. We develop an analytical model to predict parallel job response times. Our model provides insight into how significantly workstation owner interference degrades parallel program performance. A new term {\bf task ratio}, which relates the parallel task demand to the mean service demand of non parallel workstation processes, is introduced. We propose that {\bf task ratio} is a useful metric for determining how large the demand of a parallel applications must be in order to make efficient use of a non-dedicated distributed system. 3 R. Thurimella 1997 14th ACM Symposium on Principles of Distributed Computing http://www.cs.du.edu/~ramki/papers/distCerts.pdf 31 M. Lopez S. Leutenegger J. Edgington 1997 13th International Conference on Data Engineering 497-506 0 M. Lopez S. Reisner 1998 Discrete and Computational Geometry 20 163-177 31 M. Lopez Y Garcia S. Leutenegger 1998 6th International Symposium on Advances in Geographic Information Systems 163-164 31 M. Lopez Y. Garcia S. Leutenegger 1998 24th International Conference on Very Large Data Bases 334-344 31 S.T. Leutenegger M.A. Lopez 1998 1998 International Conference on Data Engineering (ICDE 1998) Past R-tree studies have focused on the number of nodes visited as a metric of query performance. Since database systems usually include a buffering mechanism we propose that the number of disk accesses is a more realistic measure of performance. We develop a buffer model to analyze the number of disk accesses required for spatial queries using R-trees. The model can be used to evaluate the quality of R-tree update operations, such as various node splitting and tree restructuring policies, as measured by query performance on the resulting tree. We use our model to study the performance of three well known R-tree packing algorithms. We show that ignoring buffer behavior and using number of nodes accessed as a performance metric can lead to incorrect conclusions, not only quantitatively, but also qualitatively. In addition, we consider the problem of how many levels of the R-tree should be pinned in the buffer. 0 M. Lopez S. Reisner 1999 Journal of Algorithms 33 1 140-165 31 J. Cheriyan R. Thurimella 1999 http://www.cs.du.edu/~ramki/papers/shredder.pdf 31 B. Schnitzer S.T. Leutenegger 1999 11th International Conference on Scientific and Statistical Database Management (SSDBM 99) Scientific databases must be able to efficiently run subset retrievals of multi-dimensional data sets. If the data sets are very large significant retrieval speedups can be obtained via parallelism. In this paper we present a new parallel distributed shared nothing R-tree architecture. To the best of our knowledge this is the first significant experimental study demonstrating practical application of parallel R-trees in a shared nothing environment. We argue that our new architecture is better than those proposed in the past and provide experimental results demonstrating actual speedups for several synthetic and real data sets. In addition, we conduct experimental studies to investigate the effect of several declustering strategies and communication parameters. 0 H. Lee 1999 Journal of Systems Architecture 45 1345-1355 31 T.Tan L. Davis R. Thurimella 1999 Content-Based Multimedia Indexing Toulouse, France http://www.cs.du.edu/~ramki/papers/OneDIndex.pdf 31 M. Lopez Y. Garcia S. Leutenegger 1999 7th ACM Symp. on Advances in Geographic Information Systems 91-96 31 G. Ghare S.T. Leutenegger 1999 IPPS'99 Workshop on Job Scheduling Strategies for Parallel Processing Gang scheduling is an effective scheduling policy for multiprocessing workloads with significant interprocess synchronization and is in common use in real installations. In this paper we show that significant improvement in the job slowdown metric can be achieved simply by allocating a different number of quanta to different rows (control groups) depending on the number of processes belonging to jobs in a given row. Specifically, we show that allocating the number of quanta inversely proportionally to the number of processes per job in that row results in 20 - 50\% smaller slowdowns without significantly affecting mean job response time. Incorporating these suggestions into real schedulers would require the addition of only a few lines of simple code, hence this work should have an immediate practical impact. 31 L. Golubchik S. Khanna S. Khuller A. Zhu 2000 Symposium on Discrete Algorithms (SODA) San Francisco http://www.cs.du.edu/~ramki/papers/gkktz2000.pdf 31 J.Cheriyan R. Thurimella 2000 http://www.cs.du.edu/~ramki/papers/spanSubgraphs.pdf 31 S.T. Leutenegger R. Sheykhet M.A. Lopez 2000 8th ACM Symposium on Advances in Geographic Information Systems (ACM GIS'2000) We present an algorithm to migrate multidimensional data in a non-replicated distributed environment. Our proposed algorithm is intented to improve query performance for mobile objects. Our algorithm automatically detects access pattern changes and migrates portions of the data from current sites of residence to sites recently accessing the data most frequently, thus reducing remote communication costs. We assume the data is indexed by an R-tree multidimensional index and that a global R-tree is used to locate and retrieve portions of the data set. We present a distributed R-tree structure % suggest a few alternatives for detecting when migration is necessary, and experimentally explore a specific access detection and migration mechanism. Our experimental results show that when compared to the no-migration case, and depending on network speed, our migration scheme may result in a query time reduction of a few percent to an order of magnitude. 31 H.Lee J. L. Welch 2000 19th ACM Symposium on Principles of Distributed Computing (PODC) 338 http://www.cs.du.edu/~hlee/Research/podcBA00.pdf 0 M. Lopez S. Reisner 2000 International Journal of Computational Geometry and Applications 10 5 445-452 31 M. Lopez S. Liao 2000 12th Annual Canadian Conference on Computational Geometry 197-204 31 M. Lopez J. Cockburn 2000 American Control Conference 4326-4330 0 S. Saltenis C.S. Jensen S.T. Leutenegger M.A. Lopez 2000 SIGMOD 2000 The coming years will witness dramatic advances in wireless communications as well as positioning technologies. As a result, tracking the changing positions of objects capable of continuous movement is becoming increasingly feasible and necessary. The present paper proposes a novel, R*-tree based indexing technique that supports the efficient querying of the current and projected future positions of such moving objects. The technique is capable of indexing objects moving in one-, two-, and three-dimensional space. Update algorithms enable the index to accommodate a dynamic data set, where objects may appear and disappear, and where changes occur in the anticipated positions of existing objects. In addition, a bulkloading algorithm is provided for building and rebuilding the index. A comprehensive performance study is reported. http://www.cs.aau.dk/research/DP/tdb/TimeCenter/publications5.html 31 M. Lopez S. Saltenis C. Jemsem S. Leutenegger 2000 ACM International Conference on Management of Data 331-342 31 G.D. Ghare S.T. Leutenegger 2000 Eighth International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunications Systems (MASCOTS 2000) Opportunistic scheduling utilizes idle workstations to execute batch jobs. Other than ensuring that each batch user receives a fair allocation of service, no work addressing opportunistic scheduling of batch jobs has been done. In this paper we propose two simple scheduling policies to be used in conjunction with the Condor Up-Down scheduling algorithm. We show that an order of magnitude reduction in mean job slowdown can be achieved by rotating a user's batch jobs within their queue. Furthermore, this improved slowdown can be achieved without a significant loss of throughput. The reduced slowdowns result in a more interactive nature of the system thus increasing its appeal. Our proposed modifications to the algorithms would require very little effort to implement. 31 A. von Mayrhauser T. Chen J. Kok A. Read A. Hajjar 2000 IEEE International High Level Design Validation and Test Workshop San Francisco http://csdl2.computer.org/persagen/DLAbsToc.jsp?resourcePath=/dl/proceedings/&toc=comp/proceedings/hldvt/2000/0786/00/0786toc.xml&DOI=10.1109/HLDVT.2000.889572 31 A. Hajjar T. Chen A. von Mayrhauser 2000 IEEE International High Level Design Validation and Test Workshop San Francisco http://csdl2.computer.org/persagen/DLAbsToc.jsp?resourcePath=/dl/proceedings/&toc=comp/proceedings/hldvt/2000/0786/00/0786toc.xml&DOI=10.1109/HLDVT.2000.889565 0 M. Lopez S. Leutenegger 2000 IEEE Transactions on Knowledge and Data Engineering 12 1 33-44 31 H. Lee J. L. Welch 2001 21st International Conference on Distributed Computing Systems (ICDCS) 21-28 2 H. Lee 2001 Philosophy Texaz A&M University 84 http://www.cs.du.edu/~hlee/Research/thesis.pdf 31 H. Lee J. L. Welch 2001 20th ACM Symposium on Principles of Distributed Computing (PODC) 311-313 0 M. Lopez S. Liao D. Mehta 2001 ACM Trans. on Design Automation of Electronic Systems 6 322-342 31 M .Lopez S. Liao S.T. Leutenegger 2001 18th International Conference on Data Engineering (ICDE) 615-622 31 S. Liao M.A. Lopez S.T. Leutenegger 2001 Int Conference on Data Engineering (ICDE 2001) We present a new approach for approximate nearest neighbor queries for sets of high dimensional points under any $L_t$-metric, $t=1,\ldots,\infty$. The proposed algorithm is efficient and simple to implement. The algorithm uses multiple shifted copies of the data points and stores them in up to $(d+1)$ B-trees where $d$ is the dimensionality of the data, sorted according to their position along a space filling curve. %such as the Hilbert curve. This is done in a way that allows us to guarantee that a neighbor within an $O(d^{1+1/t})$ factor of the exact nearest, can be returned with at most $(d+1)\log_p n$ page accesses, where $p$ is the branching factor of the B-trees. In practice, for real data sets, our approximate technique finds the {\em exact} nearest neighbor between 87\% and 99\% of the time and a point no farther than the third nearest neighbor between 98\% and 100\% of the time. Our solution is dynamic, allowing insertion or deletion of points in $O(d\log_p n)$ page accesses and generalizes easily to find approximate $k$-nearest neighbors. 31 K. M. Anderson S. A. Sherba 2001 Poster and Demo Session. 2001 ACM Conference on Hypertext Aarhus, Denmark 31 H. Lee J. L. Welch 2001 12th International Symposium on Algorithms and Computation (ISAAC) 587-598 http://www.cs.du.edu/~hlee/Research/isaac01.pdf 31 A. Hajjar T. Chen I. Munn A. Andrews M. Bjorkman 2001 Design Automation and Test in Europe Munich, Germany 31 A. Hajjar T. Chen I. Munn A. Andrews M. Bjorkman 2001 IEEE 2001 Symposium on Quality and Electronic Design San Jose http://csdl2.computer.org/persagen/DLAbsToc.jsp?resourcePath=/dl/proceedings/&toc=comp/proceedings/date/2001/0993/00/0993toc.xml&DOI=10.1109/DATE.2001.915057 31 K.M. Anderson S. A. Sherba 2001 Proceedings of the International Workshop on XML Technologies and Software Engineering (XSE 2001 Toronto, Ontario, Canada 31 S. Ghosh A. Andrews E.-M. Choi 2002 International Conference on Software Maintenance Montreal, CA http://csdl2.computer.org/persagen/DLAbsToc.jsp?resourcePath=/dl/proceedings/&toc=comp/proceedings/icsm/2002/1819/00/1819toc.xml&DOI=10.1109/ICSM.2002.1167792 31 C. Wohlin A. Andrews 2002 Proceedings of the 14th International Conference on Software Engineering and Knowledge Engineering Ischia, Italy http://portal.acm.org/citation.cfm?id=568829&coll=GUIDE&dl=GUIDE&CFID=3205658&CFTOKEN=49714004&ret=1#Fulltext 7 Joel S. Cohen 2002 Natick A K Peters, LTD 323 1-56881-158-6 The book provides a systematic approach for the algorithmic formulation of mathematical operations in computer algebra programming languages. The viewpoint is that mathematical expressions, represented by expression trees, are the data objects of computer algebra programs, and by using a few primitive operations that analyze and construct expressions, we can implement many elementary operations from algebra, trigonometry, calculus, and differential equations. A CD with full, searchable text and implementations of all algorithms in Maple, Mathematica, and MuPad is included. More advanced concepts are covered in the second book in this series, Computer Algebra and Symbolic Computation: Mathematical Methods. With a minimum of prerequisites, this book is accessible to and useful for students of mathematics, computer science, the sciences, engineering, and other technical fields. 0 M. Lopez S. Resiner 2002 Computational Geometry: Theory and Applications 23 291-301 31 K. M. Anderson S. A. Sherba W. V. Lepthien 2002 Proceedings of the 24th International Conference on Software Engineering Orlando, Florida, USA 31 K. M. Anderson S. A. Sherba 2002 Hypermedia: Openness, Structural Awareness, and Adaptivity 2266 151-159 31 S. Elbaum S. Kanduri A. Andrews 2003 Proceedings ISSRE 2003 Denver http://csdl2.computer.org/persagen/DLAbsToc.jsp?resourcePath=/dl/proceedings/&toc=comp/proceedings/issre/2003/2007/00/2007toc.xml&DOI=10.1109/ISSRE.2003.1251035 31 A. Andrews T. Chen A. O'Fallon 2003 Proceedings VLSI SoC 2003 Darmstadt 31 Susanne A. Sherba Kenneth M. Anderson Maha Faisal 2003 18th IEEE International Conference on Automated Software Engineering Montreal, Quebec, Canada 31 Susanne A. Sherba 2003 International IEEE Requirements Engineering Conference Monterey Bay, California, USA 31 Susanne A. Sherba Kenneth M. Anderson 2003 2003 International Conference on Software Engineering Portland, Oregon 31 S. Voorhies H. Lee 2003 American Association of Advancement of Science '03 Meeting 7 Joel S. Cohen 2003 Natick, MA A K Peters, LTD 448 1-56881-159-4 Applying the ideas introduced in the companion book, Computer Algebra and Symbolic Computation: Elementary Algorithms, this book explores the mathematical concepts that form the basis for computer algebra software and describes algorithms for algebraic simplification, polynomial decomposition, polynomial greatest common divisor calculation, resultant calculation, simplification with side relations, and polynomial factorization. It is well-suited for self-study and can be used as the basis for an advanced undergraduate course or a beginning graduate course in computer algebra. The book includes a CD with an electronic, hyperlinked version of the text, additional reference files, and implementations of the algorithms in the Mathematica, Maple, and MuPAD computer algebra languages. 31 P. Runeson A. Andrews 2003 Proceedings ISSRE 2003 Denver http://csdl2.computer.org/persagen/DLAbsToc.jsp?resourcePath=/dl/proceedings/&toc=comp/proceedings/issre/2003/2007/00/2007toc.xml&DOI=10.1109/ISSRE.2003.1251026 31 C. Stringfellow A. Andrews 2003 7th IASTED International Conference on Software Engineering and Applications Marina del Rey, CA http://www.actapress.com/PaperInfo.aspx?PaperID=14552 0 H. Lee J. L. Welch N. H. Vaidya. 2003 Ad Hoc Networks 1 4 371-381 http://www.cs.du.edu/~hlee/Research/LocTrack.pdf 31 Wu, H. Burt, A. Thurimella, R. 2003 19th Annual Computer Security Applications Conference Las Vegas, Nevada 3 M. Lopez D. Mehta 2003 IEEE 38th International Conference on Communications 507-511 31 O. Pilskalns A. Andrews S. Ghosh R. France 2003 UML '03 San Francisco, CA http://www.cs.colostate.edu/%7Eghosh/papers/uml2003.pdf 31 K. M. Anderson S. A. Sherba W. V. Lepthien 2003 Proceedings of the Fourteenth Conference on Hypertext and Hypermedia Nottingham, UK 0 K. M. Anderson S. A. Sherba W. V. Lepthien 2003 Journal of Network and Computer Applications 47-71 31 S. Ghosh C. Braganza R. France A. Andrews O. Pilskalns 2003 Proceedings ISSRE Denver http://csdl2.computer.org/persagen/DLAbsToc.jsp?resourcePath=/dl/proceedings/&toc=comp/proceedings/issre/2003/2007/00/2007toc.xml&DOI=10.1109/ISSRE.2003.1251054 31 K. M. Anderson S. A. Sherba 2003 Hypermedia: Openness, Structural Awareness, and Adaptivity 2266 8-16 31 J. Bieman A. Andrews H. Yang 2003 International Workshop on Program Comprehension http://csdl2.computer.org/persagen/DLAbsToc.jsp?resourcePath=/dl/proceedings/&toc=comp/proceedings/iwpc/2003/1883/00/1883toc.xml&DOI=10.1109/WPC.2003.1199188 31 L. Ran C. E. Dyreson A. Andrews 2004 Fifth International Conference on Web Information Systems Engineering Brisbane, Australia 0 M. Lopez J.M. Diaz-Banez J.A. Sellares 2004 Lecture Notes on Computer Science 3046 99-108 31 C. Stringfellow C.D. Amory D. Potnuri M. Georg A, Andrews 2004 IASTED Software Engineering Applications Conference Cambridge, Mass http://www.actapress.com/PaperInfo.aspx?PaperID=17525 31 A. O'Fallon O. Pilskalns A. Knight A. Andrews 2004 SEKE Banff, Ca http://www.vancouver.wsu.edu/fac/orest/papers/SEKE04.pdf 0 M. Lopez H.C. Kim S. Leutenegger K.J. Li 2004 Lecture Notes on Computer Science 2973 694-707 0 M. Lopez D. Mehta S. Idwan 2004 International Journal on Foundations of Computer Science 15 5 753-772 31 Hyunyoung Lee 2004 6th Workshop on Advances in Parallel and Distributed Computational Models (APDCM) in conjunction with IEEE IPDPS 2004 http://www.cs.du.edu/~hlee/Research/W07_APDCM_012.pdf 31 A. Andrews P. Runeson R. France 2004 11th International Conference on Engineering of Computer-Based Systems (ECBS) Brno, Czech Republic http://csdl2.computer.org/persagen/DLAbsToc.jsp?resourcePath=/dl/proceedings/&toc=comp/proceedings/ecbs/2004/2125/00/2125toc.xml&DOI=10.1109/ECBS.2004.1316710 31 A. Andrews A. O'Fallon T. Chen 2004 HASE '03 Tampa http://csdl2.computer.org/persagen/DLAbsToc.jsp?resourcePath=/dl/proceedings/&toc=comp/proceedings/hase/2004/2094/00/2094toc.xml&DOI=10.1109/HASE.2004.1281743 31 Hyunyoung Lee Andreas Klappenecker 2004 http://www.cs.du.edu/~hlee/Research/RS.pdf 0 A. Andrews E. Manceba P. Runeson R. France 2005 Software Quality Journal 13 4 377-405 31 T. Trung S. Ghosh R. France A. Andrews 2005 Proceedings 4th International Workshop on Critical Systems Development Using Modeling Languages http://www.cs.colostate.edu/%7Eghosh/papers/issre2003trung.pdf 31 A. Andrews A. Stefik N. Picone S. Ghosh 2005 IWPC St. Louis, MO http://csdl2.computer.org/persagen/DLAbsToc.jsp?resourcePath=/dl/proceedings/&toc=comp/proceedings/iwpc/2005/2254/00/2254toc.xml&DOI=10.1109/WPC.2005.1 31 T. Dinh-Trong N. Kawane S. Ghosh R. France A. Andrews 2005 10th IEEE International Conference on Engineering of Complex Computer Systems (ICECCS 2005) Shanghai, China http://www.cs.colostate.edu/%7Etrungdt/publication/iceccs05.pdf 31 E. Mancebo A. Andrews 2005 ACM SAC Santa Fe, NM http://delivery.acm.org/10.1145/1070000/1067017/p1505-mancebo.pdf?key1=1067017&key2=1746415511&coll=portal&dl=ACM&CFID=15151515&CFTOKEN=6184618 31 Yueh-Hua Lee Hyunyoung Lee. 2005 24th ACM Symposium on Principles of Distributed Computing (PODC 2005). http://www.cs.du.edu/~hlee/Research/podc05tech-report.pdf 31 Kevin Bauer Hyunyoung Lee 2005 2nd International Workshop on Networked Sensing Systems (INSS 2005) 210-215 http://www.cs.du.edu/~hlee/Research/inss05.pdf 31 O. PIlskalns D. Williams A. Andrews 2005 International Conference on Software Maintenance Budapest, Hungary http://www.vancouver.wsu.edu/fac/orest/papers/ICSM05.pdf 31 C. Wohlin A. Andrews 2005 PROFES http://www.springerlink.com/home/main.mpx 31 T. Din-Trong N. Kawane S. Ghosh R. France 2005 UML Modeling Languages and Applications Lisbon, Portugal http://www.springerlink.com/home/main.mpx 31 Hyunyoung Lee Andreas Klappenecker Kyungsook Lee Lan Lin 2005 Workshop on Resource Provisioning and Management in Sensor Networks (RPMSN 2005), in conjunction with The 2nd IEEE International Conference on Mobile Ad-Hoc and Sensor Systems (MASS 2005) http://www.cs.du.edu/~hlee/Research/RPMSN05.pdf 31 J. Hayes I. Raphael V. Surisetty A. Andrews 2005 Fifth European Dependable Computing Conference (EDCC-5) Budapest, Hungary http://www.cs.colostate.edu/%7Etrungdt/publication/iceccs05.pdf 31 S. Ghosh R. France T. Trong A. Andrews 2005 MoDeVa St. Vincent 0 M. Lopez S. Reisner 2005 Computational Geometry Theory and Applications 32 2 139-158 0 M. Lopez J.M. Diaz F. Hurtado J. Sellares. 2005 Journal of Visual Communication and Image Representation 16 3 233-249 31 M. Lopez S. Leutenegger 2005 D. Mehta and S. Sahni Handbook of Data Structures and Applications CRC Press 1-23 31 P. Berander A. Andrews 2005 Engineering and Managing Software Requirements 0 Hyunyoung Lee Jennifer L. Welch 2005 Distributed Computing 17 3 209-221 http://www.cs.du.edu/~hlee/Research/RR.pdf 0 A. Andrews J. Offutt R. Alexander 2005 Journal of Software and Systems Modeling 0 Mario Lopez Y. Mayster 2006 Journal of Visual Communication and Image Representation 31 Treinen, J. Thurimella, R. 2006 RAID 1-18 31 Hyunyoung Andreas Klappenecker 2006 3rd International Conference on Networked Sensing Systems (INSS 2006) 234-239 http://www.cs.du.edu/~hlee/Research/inss06.pdf 0 M. Lopez L. Argent B. Depper R. Fajardo S. Gjertson S. Leutenegger J. Rutenbeck. 2006 IEEE Computer 0 L. Argent B. Deppter R. Fajardo S. Ghertson S. Leutenegger M. Lopez J. Rutenbeck 2006 IEEE Computer http://www.cs.du.edu/~leut/DU_GD_IEEE_overview.pdf 0 C. Stringfellow C.D. Amory D. Potnuri A. Andrews M. Georg 2006 Journal of Information and Software technology 18 7 484-497 31 Lan Lin Hyunyoung Lee 2006 25th ACM Symposium on Principles of Distributed Computing (PODC 2006) http://www.cs.du.edu/~hlee/Research/dma.pdf 0 Seth Voorhies Hyunyoung Lee Andreas Klappenecker 2006 Information Processing Letters 99 96-101 http://www.cs.du.edu/~hlee/Research/elephant.pdf 0 M. Lopez J.M. Diaz-Banez J.A. Sellares 2006 European Journal of Operations Research 173 2 556-564 0 M. Lopez J.M. Diaz-Banez J.A. Sellares. 2006 Information Processing Letter 98 5 199-205 3 Rajkishore Barik Christian Grothoff Rahul Gupta Vinayaka Pandit 2006 Languages and Compilers for High Performance Computing New Orleans, USA Springer Verlag This paper addresses the problem of optimal global register allocation. The register allocation problem is expressed as an integer linear programming problem and solved optimally. The model is more flexible than previous graph-coloring based methods and thus allows for register allocations with significantly fewer moves and spills. The formulation can also model complex architectural features, such as bit-wise access to registers. With bit-wise access to registers, multiple subword temporaries can be stored in a single register and accessed efficiently, resulting in a register allocation problem that cannot be addressed effectively with simple graph coloring. The paper describes techniques that can help reduce the problem size of the ILP formulation, making the algorithm feasible in practice. Preliminary empirical results from an implementation prototype are reported. http://grothoff.org/christian/lcpc2006.pdf 0 M. Lopez Y. Mayster 2006 Lecture Notes in Computer Science 3887 715-726 31 O. Pilskalns G. Uyan A. Andrews 2006 International Conference on Software Maintenance Philadelphia, PA 31 R. Hewitt A. Kulkarni C. Stringfellow A. Andrews 2006 SEKE 2006 San Francisco, CA 31 O. Pilskalns D. Williams D. Aracic A. Andrews 2006 COMPSAC 2006 Chicago 31 O. Pilskalns A. Andrews 2006 SEKE 2006 San Francisco, CA 0 P. Runeson C. Anderson T. Thelin A. Andrews T. Berling 2006 IEEE Software 23 3 82-90 31 Daniel Pittman Chris GauthierDickey 2007 NetGames 2007 Melbourne, Australia 19/09/2007 Understanding the distributions and behaviors of players within Massively Multiplayer Online Games (MMOGs) is essential for research in scalable architectures for these systems. We provide the first look into this problem through a measurement study on one of the most popular MMOGs, World of Warcraft [15]. Our goal is to answer four fundamental questions: how does the population of the virtual world change over time, how are players distributed in the virtual world, how much churn occurs with players, and how do they move in the virtual world. Through probing-based measurements, our preliminary results show that populations fluctuate according to a prime-time schedule, player distribution and churn appears to occur on a power-law distribution, and players move to only a small number of zones during each playing session. The ultimate goal of our research is to design an accurate player model for MMOGs so that future research can predict and simulate player behavior and population fluctuations over time. http://www.cs.du.edu/~chrisg/publications/pittman-netgames07.pdf 3 Nathan S. Evans Chris GauthierDickey Christian Grothoff 2007 Annual Computer Security Applications Conference Miami Beach, Florida, USA 10/12/2007 In many networks, such as mobile ad-hoc networks and friend-to-friend overlay networks, direct communication between nodes is limited to specific neighbors. Often these networks have a small-world topology; while short paths exist between any pair of nodes in small-world networks, it is non-trivial to determine such paths with a distributed algorithm. Recently, Clarke and Sandberg proposed the first decentralized routing algorithm that achieves efficient routing in such small-world networks. This paper is the first independent security analysis of Clarke and Sandberg's routing algorithm. We show that a relatively weak participating adversary can render the overlay ineffective without being detected, resulting in significant data loss due to the resulting load imbalance. We have measured the impact of the attack in a testbed of 800 nodes using minor modifications to Clarke and Sandberg's implementation of their routing algorithm in Freenet. Our experiments show that the attack is highly effective, allowing a small number of malicious nodes to cause rapid loss of data on the entire network. We also discuss various proposed countermeasures designed to detect, thwart or limit the attack. While we were unable to find effective countermeasures, we hope that the presented analysis will be a first step towards the design of secure distributed routing algorithms for restricted-route topologies. http://grothoff.org/christian/pitchblack.pdf 0 S. Elbaum S. Kanduri A. Andrews 2007 Empirical Software Engineering Journal 12 5 31 Treinen, J. Thurimella, R. 2007 Ninth International Conference on Information and Communications Security (ICICS 2007) Springer 31 Lan Lin Hyunyoung Lee 2007 2th IEEE International Conference on Embedded and Real-Time Computing Systems and Applications (RTCSA 2007) 31 Lan Lin Hyunyoung Lee 2007 ISCA 20th International Conference on Parallel and Distributed Computing Systems (PDCS 2007) 31 Lan Lin Hyunyoung Lee 2007 26th ACM Symposium on Principles of Distributed Computing (PODC 2007) 0 Christian Grothoff Jens Palsberg Jan Vitek 2007 ACM Transactions on Programming Languages and Systems ACM 29 6 types, encapsulation, java, escape analysis Object-oriented languages provide little support for encapsulating objects. Reference semantics allows objects to escape their defining scope, and the pervasive aliasing that ensues remains a major source of software defects. This paper presents Kacheck/J a tool for inferring object encapsulation properties of large Java programs. Our goal is to develop practical tools to assist software engineers, thus we focus on simple and scalable techniques. Kacheck/J is able to infer confinement -- the property that all instances of a given type are encapsulated in their defining package. This simple property can be used to identify accidental leaks of sensitive objects, as well as for compiler optimizations. We report on the analysis of a large body of code and discuss language support and refactoring for confinement. http://grothoff.org/christian/toplas.pdf 0 Christian Grothoff Krista Grothoff Ryan Stutsman Ludmila Alkhutova Mikhail Atallah 2007 Journal of Computer Security This paper investigates systems that steganographically embed information in the ``noise'' created by automatic translation of natural language documents. The main thrust of the work focuses on two problems - generation of plausible steganographic texts, and avoiding transmission of the original source for stego objects. Because the inherent redundancy of natural language creates plenty of room for variation in translation, machine translation is ideal for steganographic applications. We describe the design and implementation of a scheme for hiding information in translated natural language text and present experimental results using the implemented system. While the initial work in this vein required the presence of both the source and the translation, the system detailed in this paper requires only the translated text for recovering the hidden message, increasing security and improving resource usage. These improvements occur not only because the source text is no longer available to the adversary, but also because a broader repertoire of defenses (such as mixing human and machine translation) can now be used. http://grothoff.org/christian/lit.pdf 31 Michel Dubois Hyunyoung Lee Lan Lin 2007 Proceedings of the 21st IEEE International Parallel & Distributed Processing Symposium (IPDPS 2007): Workshop on Multithreaded Architectures and Applications (MTAAP 2007) http://www.cs.du.edu/~hlee/Research/stamp.pdf 0 O. Pilskalns A. Andrews A. Knight S. Ghosh R. France 2007 Journal of Information and Software technology 19 8 192-212 Early detection and correction of faults in the software design phase can reduce total cost and time to market of a software product. In this paper we describe an approach for testing UML design models to uncover inconsistencies. Our approach uses behavioral views such as Sequence Diagrams to simulate state change in an aggregate model. The aggregate model is the artifact of merging information from behavioral and structural UML views. OCL pre-conditions, post-conditions and invariants are used as a test oracle. 31 Susanne A. Sherba Kenneth M. Anderson 2007 2007 International Conference on Software Engineering Research and Practice Las Vegas, Nevada, USA 0 Nils Durner Nathan S. Evans Christian Grothoff 2007 c't magazin für computer technik Heise Zeitschriftenverlag 21 218-221 0 Nils Durner Nathan S. Evans Christian Grothoff 2008 iX magazin für professionelle informationstechnik Heise Verlag 88-94 9/2008 http://www.heise.de/kiosk/archiv/ix/2008/9 3 Chris GauthierDickey Christian Grothoff 2008 International Workshop on Dependable and Sustainable Peer-to-Peer Systems Turku, Finland IEEE 28/07/2008 In this paper, we present the first heuristic for fully distributed bootstrapping of peer-to-peer networks. Our heuristic generates a stream of promising IP addresses to be probed as entry points. This stream is generated using statistical profiles using the IP ranges of start-of-authorities (SOAs) in the domain name system (DNS). We present experimental results demonstrating that with this approach it is efficient and practical to bootstrap Gnutella-sized peer-to-peer networks - without the need for centralized services or the public exposure of end-user's private IP addresses. 31 Jeff Boleng Thorsten Wirges Dino Schweitzer Seana Hagerman Ramakrishna Thurimella 2008 The 3rd International Conference on i-Warfare & Security Nebraska 51-58 24/04/2008 RF collection, visualization, data fusion, system integration In today's net-centric warfare environment, effective management and use of the electromagnetic spectrum is critical. Increasing demands on wireless spectrum from radio traffic, unmanned aerial vehicle (UAV) communication, wireless networks, improvised explosive device (IED) jammers, and sensor networks result in sources competing for, and at times conflicting over, limited frequency spectrum. From an intelligence perspective, having a clear understanding of the RF environment, both friendly and foe, is an important essential of battlefield management. This paper presents the Sensor Collection and Analysis of Radio Frequencies (SCARF) system with a focus on the information processing requirements of the sensors and various system components. The overall architecture, sensor processing and fusion challenges, visualization algorithms, and current implementation status are discussed. 31 Gabor Papp Chris GauthierDickey 2008 19th ITC Specialist Seminar on Network Usage and Traffic Berlin, Germany 08/10/2008 3 Gabor Papp Chris GauthierDickey 2008 ACM Sigmetrics Annapolis, Maryland 02/06/2008 0 Andrew Burt Michael Darschewski Indrajit Ray Ramakrishna Thurimella Hailin Wu 2008 International Journal of Security and Networks (IJSN) InderScience 3 1 36-46 01/2008 computer worm attacks, attack trace-back, network security, internet worms, intrusion detection, simulation, worm origins An automatic distributed mechanism is proposed to identify the propagation roots of fast spreading internet worms. The information obtained can be used to identify local worm outbreaks, identify network intrusion, identify internal network misuse, and help with the forensic trace-back after detection. It has been designed with simplicity, efficacy, and ease of deployment in mind. Two modes of operation are possible, yielding both real-time and post mortem propagation information. The proposed paradigm can work in unison with any intrusion detection, throttling and human-mediated responses. Simulation results show that even with only 20–30% deployment, worm origins can be pinpointed with great precision. 0 Leana Golubchik Sanjiv Khanna Samir Khuller Ramakrishna Thurimella An Zhu 2008 ACM Transactions on Algorithms, to appear 3 Nathaniel Nystrom Vijay Saraswat Jens Palsberg Christian Grothoff 2008 16th ACM SIGPLAN conference on Object-oriented programing, systems, languages, and applications ACM SIGPLAN http://grothoff.org/christian/oopsla2008.pdf 31 Pritchard, D. Thurimella, R. 2008 31 A. Mahdian A. Andrews 2008 Advances in Computers 0 Christian Grothoff 2008 Software: Practice and Experience This paper presents a variation of the visitor pattern which allows programmers to write visitor-like code in a concise way. The Runabout is a library extension that adds a limited form of multi-dispatch to Java. While the Runabout is not as expressive as a general multiple dispatching facility, the Runabout can be significantly faster than existing implementations of multiple dispatch for Java, such as MultiJava. Unlike MultiJava, the Runabout does not require changes to the syntax and the compiler. This paper illustrates how to use the Runabout, details its implementation, and provides benchmarks comparing its performance with other approaches. Furthermore, the effect of an automatic static program transformation tool that translates bytecode using the Runabout to equivalent bytecode is evaluated. The tool uses double dispatch and runtime type checks to achieve the same semantics that the Runabout has. The performance comparisons on large benchmarks that make extensive use multiple dispatch show that using the Runabout does not result in a significant loss of performance for realistic applications and that, depending on the application and platform, small performance gains are also possible. http://grothoff.org/christian/spe.pdf