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Corrected phase-type approximations for the workload of the MAP/G/1 queue with heavy-tailed service times

Eleni Vatamidou, Ivo Adan, Maria Vlasiou, Bert Zwart
2013 Performance Evaluation Review  
With the aid of perturbation analysis, we derive our approximations as a sum of the workload distribution of the MAP/PH/1 queue and a heavy-tailed component that depends on the perturbation parameter.  ...  Motivated by statistical analysis, we assume that the service times are a mixture of a phase-type and a heavy-tailed distribution.  ...  With the aid of perturbation analysis, we derive our approximations as a sum of the workload distribution of the MAP/PH/1 queue and a heavy-tailed component that depends on the perturbation parameter.  ... 
doi:10.1145/2518025.2518036 fatcat:rdhxnmfhsjggtpexftgeakq3sa

Evaluations of Web Server Performance with Heavy-tailedness

Takuo Nakashima
2007 IPSJ Digital Courier  
HTTP traffic, mainly consisting of file transmission traffic, depends on the sizes of files with a heavy-tailed property.  ...  Crovella's well known work merely describes the self-similar properties for the total transmission time generated by a heavy-tailed file size distribution.  ...  It indicates that a host with heavy-tailedness will be plotted at the tail part of the mean value in Fig. 8 (a) and (b).  ... 
doi:10.2197/ipsjdc.3.21 fatcat:fjslfemm2jhcrdehzdfxivzhsm

Optimal Randomness for Stochastic Configuration Network (SCN) with Heavy-Tailed Distributions

Haoyu Niu, Jiamin Wei, YangQuan Chen
2020 Entropy  
Experimental results showed improved performance for SCN with heavy-tailed distributions.  ...  Heavy-tailed distributions, such as Lévy distribution, Cauchy distribution, and Weibull distribution, have been used.  ...  Acknowledgments: We gratefully acknowledge the support of NVIDIA Corporation with the donation of the Titan X Pascal GPU used for this research.  ... 
doi:10.3390/e23010056 pmid:33396383 fatcat:cpnrrh5pp5gqjcbnyxs7sdf32u

The fundamentals of heavy-tails

Jayakrishnan Nair, Adam Wierman, Bert Zwart
2013 Performance Evaluation Review  
Heavy-tailed distributions Tutorial overview Heavy-tails are a continual source of excitement and confusion across disciplines as they are repeatedly "discovered" in new contexts.  ...  ) by showing that a wide variety of general processes lead to heavy-tailed distributions; and we will highlight that most of the controversy surrounding heavy-tails is the result of bad statistics, and  ...  ) by showing that a wide variety of general processes lead to heavy-tailed distributions; and we will highlight that most of the controversy surrounding heavy-tails is the result of bad statistics, and  ... 
doi:10.1145/2494232.2466587 fatcat:ytjiyb7rtzg3nm4d2wok4olq7m

The beneficiation of tailing of coal preparation plant by heavy-medium cyclone

Ataallah Bahrami, Yousef Ghorbani, Mirsaleh Mirmohammadi, Behnam Sheykhi, Fatemeh Kazemi
2018 International Journal of Coal Science & Technology  
Finally, it could be said that the performance of a cyclone with a heavy medium of 1.40 g/cm 3 specific weight is desirable compared with other specific weights.  ...  For this purpose, separation tests were conducted using spiral concentrator and heavy medium cyclones with the specific weight of medium 1.3-1.8 (g/cm 3 ) on different grading fractions of tailing in an  ...  Plotting the Tromp distribution curve The performance of gravity separation equipment's is evaluated by distribution curves.  ... 
doi:10.1007/s40789-018-0221-6 fatcat:xeda2bno4ndcdmd3tw6yt5tpeq

Robust ambulance allocation using risk-based metrics

Kaushik Krishnan, Lavanya Marla, Yisong Yue
2016 2016 8th International Conference on Communication Systems and Networks (COMSNETS)  
From our computational results based on data from a large Asian city, we show that planning with some robustness metrics as targets leads to solutions that perform well in heavy-tailed demand scenarios  ...  system behaving in a heavy-tailed manner.  ...  light-tailed request logs with hotspots Fig. 4 . 4 Performance of risk-optimized allocation on heavy-tailed request logs with hotspots COMSNETS 2016: Intelligent Transportation Systems Workshop  ... 
doi:10.1109/comsnets.2016.7439958 dblp:conf/comsnets/KrishnanMY16 fatcat:xdnn4pjfgncmtacsyvtakrooti

Left Heavy Tails and the Effectiveness of the Policy and Value Networks in DNN-based best-first search for Sokoban Planning [article]

Dieqiao Feng, Carla Gomes, Bart Selman
2022 arXiv   pre-print
To further understand the phenomena, we studied the cost distribution of the search algorithms and found that Sokoban instances can have heavy-tailed runtime distributions, with tails both on the left  ...  The experiments show the critical role of the policy network as a powerful heuristic guiding the search, which can lead to left heavy tails with polynomial scaling by avoiding exploring exponentially sized  ...  Our runtime distribution results show heavy-tailed distributions with tails on both the left and right-hand sides. Left heavy tails have not been observed in combinatorial search before.  ... 
arXiv:2206.14298v1 fatcat:7zdwvvv3gvf7bebhgdbvj2p6zq

Spliced Binned-Pareto Distribution for Robust Modeling of Heavy-tailed Time Series [article]

Elena Ehrlich, Laurent Callot, François-Xavier Aubet
2022 arXiv   pre-print
This work proposes a novel method to robustly and accurately model time series with heavy-tailed noise, in non-stationary scenarios.  ...  In many practical application time series have heavy-tailed noise that significantly impacts the performance of classical forecasting models; in particular, accurately modeling a distribution over extreme  ...  Table 2b shows that, while in the setting with simple time dependencies and symmetric tail heaviness our method performs comparably to other method, in the real scenario the advantage of our method's  ... 
arXiv:2106.10952v2 fatcat:s24mmpcm5jezhn72wbpdnnpkfy

Improving efficiency in software maintenance

Sergey Zeltyn, Perri Tarr, Murray Cantor, Robert Delmonico, Sateesh Kannegala, Mila Keren, Ashok Pon Kumar, Segev Wasserkrug
2011 Proceeding of the 8th working conference on Mining software repositories - MSR '11  
We performed such an evaluation by mining and analyzing many years of support data on multiple IBM products.  ...  Using percentiles, we also identified statistical techniques to detect efficiency trends and evaluated their accuracy.  ...  Finding 1: Handling times for SEM defect reports exhibit a heavy-tailed distribution. Moreover, this distribution is not one of the well-known heavy-tailed distributions.  ... 
doi:10.1145/1985441.1985474 dblp:conf/msr/ZeltynTCDKKKW11 fatcat:sgc2iaukgrhudhpdauhw7pvx7i

Why do programs have heavy tails?

Hiroshi Sasaki, Fang-Hsiang Su, Teruo Tanimoto, Simha Sethumadhavan
2017 2017 IEEE International Symposium on Workload Characterization (IISWC)  
Finally, we describe conditions under which skew emerges within programs and provide evidence that suggests that the heavy-tailed distributions are a unique program property.  ...  One prominent result is that the outdegree of instructions follow heavy tails or power law distributions, i.e., a few instructions produce values for many instructions while most instructions do so for  ...  For this purpose, we perform the same evaluations with the previous section using binaries compiled with LLVM (-O0 to -O2) and GCC (-O0 to -O3).  ... 
doi:10.1109/iiswc.2017.8167771 dblp:conf/iiswc/SasakiSTS17 fatcat:nknv6io6dngqvcvkheyk5aehpe

Heavy-tailed Rayleigh Distribution: Basic Properties and Their Applications

Zeng-Guo SUN
2009 ACTA AUTOMATICA SINICA  
Heavy-tailed exponential distribution is a direct and necessary extension of the heavy-tailed Rayleigh distribution.  ...  First, some basic properties of heavy-tailed exponential distribution are introduced in this paper including the series form of the density function, the heavy-tailed property and the nonexistence of finite  ...  Obviously, better performance is achieved with bigger block size.  ... 
doi:10.3724/sp.j.1004.2008.01067 fatcat:7yiv4mnok5e3rhwj3ugrsimc54

Uptime and downtime analysis for hierarchical redundant systems in telecommunications

E. G. Coffman, Y. Kogan, W. Lai, V. Ramaswami
2012 Performance Evaluation Review  
Next, we provide an analysis that fits the downtimes by a heavy-tailed log PH distribution.  ...  We evaluate these systems using two measures: generalized uptime and traditional downtime.  ...  We chose the heavy tailed class of log-phase type distributions introduced by Ramaswami for fitting the data.  ... 
doi:10.1145/2425248.2425262 fatcat:4diejbwq7rdeffzhp534lmfd7e

Impact of Censored Sampling on the Performance of Restart Strategies [chapter]

Matteo Gagliolo, Jürgen Schmidhuber
2006 Lecture Notes in Computer Science  
Due to the "heavy-tailed" runtime distribution, a modest censoring can already reduce training time by a few orders of magnitudes.  ...  model of runtime distribution.  ...  We expect analogous results with any heavy-tailed randomized algorithm.  ... 
doi:10.1007/11889205_14 fatcat:anfqslxuzvdadpr6fplybk6g4m

Long-lasting transient conditions in simulations with heavy-tailed workloads

Mark E. Crovella, Lester Lipsky
1997 Proceedings of the 29th conference on Winter simulation - WSC '97  
Recent evidence suggests that some characteristics of computer and telecommunications systems may be well described using heavy tailed distributions -distributions whose tail declines like a power law,  ...  As a result, system designers are increasingly interested in employing heavy-tailed distributions in simulation workloads.  ...  Figure 1 : 1 Sample Data from Heavy Tailed Distribution with α = 1.2 Figure 2 : 2 .  ... 
doi:10.1145/268437.268733 fatcat:fe6qqytwhvdxhmewwiaxdwany4

From Microbiology to Microcontrollers: Robot Search Patterns Inspired by T Cell Movement

G. Matthew Fricke, François Asperti-Boursin, Joshua Hecker, Judy Cannon, Melanie Moses
2013 Advances in Artificial Life, ECAL 2013  
We find that the distribution of step-sizes taken by T cells are best described by heavy-tailed (Lévy-like) distributions.  ...  The mechanisms that cause heavy-tailed movement patterns in T cells are not fully understood.  ...  Evaluation of the search performance in simulation reinforces the functional similarity between the two heavy-tailed distributions (lognormal and power-law) and the gamma distribution which was parameterized  ... 
doi:10.7551/978-0-262-31709-2-ch151 dblp:conf/ecal/FrickeAHCM13 fatcat:vtqwgxth2jagdg57shzko46hmm
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