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Skew

About: Skew is a research topic. Over the lifetime, 8792 publications have been published within this topic receiving 98985 citations.


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Journal ArticleDOI
TL;DR: In this paper, a fully integrated phase-locked loop (PLL) is used to time-align the hi-Z/low-Z transitions of a CMOS CPU and its floating-point coprocessor.
Abstract: A fully integrated phase-locked loop (PLL) is used to time-align the hi-Z/low-Z transitions of a CMOS CPU and its floating-point coprocessor (FPC), resulting in minimum timing difference (skew) between the two devices at their shared data bus, and decreasing the bus cycle time. The PLL circuit abandons the traditional voltage-controlled oscillator function, instead using a CMOS voltage-controlled delay line to improve noise immunity, ease loop stabilization, and permit dynamically adjustable clock periods. With the PLL enable, measured timing skew between the CPU and FPC is below 1 ns. >

356 citations

Journal ArticleDOI
TL;DR: In this article, the authors present conditions générales d'utilisation (http://www.numdam.org/conditions), i.e., Toute copie ou impression de ce fichier doit contenir la présente mention de copyright.
Abstract: © Publications mathématiques de l’I.H.É.S., 1969, tous droits réservés. L’accès aux archives de la revue « Publications mathématiques de l’I.H.É.S. » (http:// www.ihes.fr/IHES/Publications/Publications.html) implique l’accord avec les conditions générales d’utilisation (http://www.numdam.org/conditions). Toute utilisation commerciale ou impression systématique est constitutive d’une infraction pénale. Toute copie ou impression de ce fichier doit contenir la présente mention de copyright.

352 citations

Journal ArticleDOI
TL;DR: In this article, a special case of the generalized hyperbolic (GH) family, called the GH skew Student's t-distribution, has been proposed, which has the important property that one tail has polynomial and the other exponential behavior.
Abstract: In this article we argue for a special case of the generalized hyperbolic (GH) family that we denote as the GH skew Student’s t-distribution. This distribution has the important property that one tail has polynomial and the other exponential behavior. Further, it is the only subclass of the GH family of distributions having this property. Although the GH skew Student’s t-distribution has been previously proposed in the literature, it is not well known, and specifically, its special tail behavior has not been addressed. This article presents empirical evidence of exponential/polynomial tail behavior in skew financial data, and demonstrates the superiority of the GH skew Student’s t-distribution with respect to data fit compared with some of its competitors. Through VaR and expected shortfall calculations we show why the exponential/polynomial tail behavior is important in practice.

351 citations

Journal ArticleDOI
TL;DR: In this article, a tractable skew t-distribution on the real line is proposed, which is potentially useful both for modelling data and in robustness studies, and properties of the new distribution are presented.
Abstract: Summary: A tractable skew t-distribution on the real line is proposed. This includes as a special case the symmetric t-distribution, and otherwise provides skew extensions thereof. The distribution is potentially useful both for modelling data and in robustness studies. Properties of the new distribution are presented. Likelihood inference for the parameters of this skew t-distribution is developed. Application is made to two data modelling examples.

333 citations

Proceedings ArticleDOI
20 May 2012
TL;DR: A novel approach to automatically partitioning databases for enterprise-class OLTP systems that significantly extends the state of the art by minimizing the number distributed transactions, while concurrently mitigating the effects of temporal skew in both the data distribution and accesses is presented.
Abstract: The advent of affordable, shared-nothing computing systems portends a new class of parallel database management systems (DBMS) for on-line transaction processing (OLTP) applications that scale without sacrificing ACID guarantees [7, 9]. The performance of these DBMSs is predicated on the existence of an optimal database design that is tailored for the unique characteristics of OLTP workloads. Deriving such designs for modern DBMSs is difficult, especially for enterprise-class OLTP systems, since they impose extra challenges: the use of stored procedures, the need for load balancing in the presence of time-varying skew, complex schemas, and deployments with larger number of partitions.To this purpose, we present a novel approach to automatically partitioning databases for enterprise-class OLTP systems that significantly extends the state of the art by: (1) minimizing the number distributed transactions, while concurrently mitigating the effects of temporal skew in both the data distribution and accesses, (2) extending the design space to include replicated secondary indexes, (4) organically handling stored procedure routing, and (3) scaling of schema complexity, data size, and number of partitions. This effort builds on two key technical contributions: an analytical cost model that can be used to quickly estimate the relative coordination cost and skew for a given workload and a candidate database design, and an informed exploration of the huge solution space based on large neighborhood search. To evaluate our methods, we integrated our database design tool with a high-performance parallel, main memory DBMS and compared our methods against both popular heuristics and a state-of-the-art research prototype [17]. Using a diverse set of benchmarks, we show that our approach improves throughput by up to a factor of 16x over these other approaches.

324 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20242
2023443
2022984
2021361
2020371
2019370