948 research outputs found
Efficient data reconfiguration for today's cloud systems
No full textDSpace SAF Submission Ingestion Package generated from Vireo submission #13052 on 2019-02-05 at 11:08:44Made available in DSpace on 2019-02-06T19:32:48Z (GMT). No. of bitstreams: 2
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Previous issue date: 2018-11-12Performance of big data systems largely relies on efficient data reconfiguration techniques. Data reconfiguration operations deal with changing configuration parameters that affect data layout in a system. They could be user-initiated like changing shard key, block size in NoSQL databases, or system-initiated like changing replication in distributed interactive analytics engine. Current data reconfiguration schemes are heuristics at best and often do not scale well as data volume grows. As a result, system performance suffers.
In this thesis, we show that {\it data reconfiguration mechanisms can be done in the background by using new optimal or near-optimal algorithms coupling them with performant system designs}. We explore four different data reconfiguration operations affecting three popular types of systems -- storage, real-time analytics and batch analytics. In NoSQL databases (storage), we explore new strategies for changing table-level configuration and for compaction as they improve read/write latencies. In distributed interactive analytics engines, a good replication algorithm can save costs by judiciously using memory that is sufficient to provide the highest throughput and low latency for queries. Finally, in batch processing systems, we explore prefetching and caching strategies that can improve the number of production jobs meeting their SLOs. All these operations happen in the background without affecting the fast path.
Our contributions in each of the problems are two-fold -- 1) we model the problem and design algorithms inspired from well-known theoretical abstractions, 2) we design and build a system on top of popular open source systems used in companies today. Finally, using real-life workloads, we evaluate the efficacy of our solutions. Morphus and Parqua provide several 9s of availability while changing table level configuration parameters in databases. By halving memory usage in distributed interactive analytics engine, Getafix reduces cost of deploying the system by 10 million dollars annually and improves query throughput. We are the first to model the problem of compaction and provide formal bounds on their runtime. Finally, NetCachier helps 30\% more production jobs to meet their SLOs compared to existing state-of-the-art.Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2019-02-05 without embargo termsThe student, Mainak Ghosh, accepted the attached license on 2018-10-30 at 01:27.The student, Mainak Ghosh, submitted this Dissertation for approval on 2018-10-30 at 01:54.This Dissertation was approved for publication on 2018-11-12 at 11:52
Copula regression and robustness
No full textThis thesis aims to study the application of copula-based regression method and its robustness. In the first chapter, we will briefly review the fundamentals of copula theory with some important results. For the second chapter, we will combine some copula selection criteria and then simulate data sets from different kinds of copulas and apply the copula-based regression method on these data sets and demonstrate why it performs better than the non-parametric regression method.
Subsequently, the third chapter will be the application on a real data set. Moreover, we will check the model's adequacy using another result from the goodness of fit for the copula models and apply the copula-based regression method to build a confidence interval of the prediction values. Finally, we will analyze and draw conclusion from these results and make some further research suggestions.Embargo status: Restricted until August 2023. To request access, contact the author-- https://www.researchgate.net/publication/332736848_Robust_Predictive_Model_Using_Copula
Spatiotemporal distribution of PM2.5 and health risk assessment in Kolkata, India: Evaluation of non-carcinogenic health hazards and premature mortality
No full textTesticular germ cell tumor fungating through anterior abdominal wall
No full textRetroperitoneal lymph node metastases from testicular germ cell tumor are common, but fungation of such mass through the anterior abdominal wall is extremely rare. We report such a case which had a favorable response to chemotherapy
Using Media Articles About Company Strategies To Teach Economics To MBA Students
No full textIn this paper, the author expands on the idea of using up-to-date examples to teach applications of economic concepts. In the MBA Managerial Economics class, the author use profiles of two companies’ decision-making strategies and their successes to show the applications of economic concepts used by the companies. This provides an even clearer relationship between economics and the real world as students are able to follow the entire story of one company and relate different economic concepts that this firm has used during the part of their existence that is profiled. This provides a stronger link between the real life business world and economic concepts than before
Mammalian target of rapamycin inhibitors: A paradigm shift in current immunosuppression protocols
No full textImmunosuppression is an obligate necessity in kidney transplant. However, the standard immunosuppression causes chronic deterioration of allograft function over long term use. Mammalian target of rapamycin (mTOR) inhibitors provide an alternative in such scenario. The mTOR inhibitors engage FKBP12 to create complexes that engage and inhibit the target of rapamycin. Inhibition of the TOR blocks signal 3 by preventing cytokine receptors from activating the cell cycle. mTOR inhibitors are associated with less viral infection and disease in kidney transplants and also beneficial in post-transplant malignancy. There are various strategies of using mTOR inhibitors either as upfront de novo therapy or later on as switch over therapy. They can also be used in cases of complications arising from standard immunosuppression. mTOR inhibitors also have adverse effects which can be managed by dose reduction but may require stoppage in case of serious complications. Surgical issues need to be kept in mind in view of delayed wound healing. mTOR inhibitors add on to the armamentarium of the available immunosuppression and can give excellent results with judicious use. The present review aims to provide updated information regarding the use of these drugs in post-renal transplantation setting
The Odd Log-Logistic Dagum Distribution: Properties and Applications
No full textThis paper introduces a new four-parameter lifetime model called the odd log-logistic Dagum distribution. The new model has the advantage of being capable of modeling various shapes of aging and failure criteria. We derive some structural properties of the model odd log-logistic Dagum such as order statistics and incomplete moments. The maximum likelihood method is used to estimate the model parameters. Simulation results to assess the performance of the maximum likelihood estimation are discussed. We prove empirically the importance and flexibility of the new model in modeling real data.</jats:p
On discriminating between Libby-Novick generalized beta and Kumaraswamy distributions: theory and methods
No full textIn fitting a continuous bounded data, the generalized beta (and several
variants of this distribution) and the two-parameter Kumaraswamy (KW)
distributions are the two most prominent univariate continuous distributions
that come to our mind. There are some common features between these two rival
probability models and to select one of them in a practical situation can be of
great interest. Consequently, in this paper, we discuss various methods of
selection between the generalized beta proposed by Libby and Novick (1982)
(LNGB) and the KW distributions, such as the criteria based on probability of
correct selection which is an improvement over the likelihood ratio statistic
approach, and also based on pseudo-distance measures. We obtain an
approximation for the probability of correct selection under the hypotheses
HLNGB and HKW , and select the model that maximizes it. However, our proposal
is more appealing in the sense that we provide the comparison study for the
LNGB distribution that subsumes both types of classical beta and exponentiated
generators (see, for details, Cordeiro et al. 2014; Libby and Novick 1982)
which can be a natural competitor of a two-parameter KW distribution in an
appropriate scenario.Comment: 11 page
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