A parametrized sorting System for a large set of k-bit elements

In this paper, we describe a parametrized sorting system for a large set of k-bit elements. The structure of the system is independent from the problem size (the number of elements to be sorted) and the type of the sorting set (for example, a set of k-bit numbers, an alphabetical list of k-bit words etc.), as well as from the ordering relation defined on the set of the elements (such as ascending or descending order of k-bit numbers, or a specific order of alphabetical words). The general structure of the underlying parallel network is based on the n- dimensional hypercube. The node circuit construction defines the type of the sorting elements, thus defining the semantics of the system. The structure of the circuit implements the Columnsort algorithm introduced by Leighton in [Lei85]. By changing only one subcircuit of the size O(k) in the node, we can define different ordering relations of the sorted elements. The system is based on specific VLSI chips that were developed in [Gam96] with the CAD system Cadic [Bur95], that has been developed in the project B1 "VLSI design systems and parallelity" under guidance of Prof. G. Hotz. The result is a fast system that sorts the sets of up to 2^28 64-bit numbers. The maximal sorting time is less than 43.6 seconds that is better than some of the fastest software realizations implemented at 32-processor Paragon ([Hard96]), Cray Y-MP ([ZagBlel91]) and MasPar MP-1 ([BrockWan97])

Designing correct recursive circuits using semantics-preserving transformations of nets

This paper will present a method of formal synthesis to design correct recursive circuits by using semantics-preserving transformations of nets (SPTNs). Its theoretical base is an algebraic calculus of nets. The calculus of nets is a hardware-specific calculus, and the transformations are circuit transformations themselves. Thus, it is much better adapted to the synthesis domain. The start point of the method is a conceptually simple specification for the required function. This specification can be easily proved to be correct, thereby the perplexed problem of the specification validation can be avoided. The specification is described compactly and graphically by a small kernel of recursive equations, and the synthesis task is simplified to transform these recursive equations in in the kernel. Because only semantics-preserving transformations are allowed in synthesis procedures, the synthesis result is not only a hardware implementation, but also a proof of correctness. We will illustrate two ways to transform a basic sorter into a odd-even-merging sorter, one being based on local incremantal transformations and the other being based on global partitions. The results show that there are circuits of practical interest, which can derived formally by using this method

Approximation of Discs by Octagons on Pixel-Plane via Jaccards Proximity Criterion: Theoretical Approach and Experimental Results Analysis

In the present paper we study approximation of discs by octagons on the pixel plane. To decide which octagon approximates better the given disc we use Jaccard's distance. The table of Jaccard's distances (calculated by a software created for these purposes) are presented at the end of the paper. The results for proximity are given in the form of a graph. Some properties of considered octagons are also studie

A parametrized sorting System for a large set of k-bit elements

In this paper, we describe a parametrized sorting system for a large set of k-bit elements. The structure of the system is independent from the problem size (the number of elements to be sorted) and the type of the sorting set (for example, a set of k-bit numbers, an alphabetical list of k-bit words etc.), as well as from the ordering relation defined on the set of the elements (such as ascending or descending order of k-bit numbers, or a specific order of alphabetical words). The general structure of the underlying parallel network is based on the n- dimensional hypercube. The node circuit construction defines the type of the sorting elements, thus defining the semantics of the system. The structure of the circuit implements the Columnsort algorithm introduced by Leighton in [Lei85]. By changing only one subcircuit of the size O(k) in the node, we can define different ordering relations of the sorted elements. The system is based on specific VLSI chips that were developed in [Gam96] with the CAD system Cadic [Bur95], that has been developed in the project B1 "VLSI design systems and parallelity" under guidance of Prof. G. Hotz. The result is a fast system that sorts the sets of up to 2^28 64-bit numbers. The maximal sorting time is less than 43.6 seconds that is better than some of the fastest software realizations implemented at 32-processor Paragon ([Hard96]), Cray Y-MP ([ZagBlel91]) and MasPar MP-1 ([BrockWan97])

Massive migration from the steppe is a source for Indo-European languages in Europe

We generated genome-wide data from 69 Europeans who lived between 8,000-3,000 years ago by enriching ancient DNA libraries for a target set of almost four hundred thousand polymorphisms. Enrichment of these positions decreases the sequencing required for genome-wide ancient DNA analysis by a median of around 250-fold, allowing us to study an order of magnitude more individuals than previous studies and to obtain new insights about the past. We show that the populations of western and far eastern Europe followed opposite trajectories between 8,000-5,000 years ago. At the beginning of the Neolithic period in Europe, ~8,000-7,000 years ago, closely related groups of early farmers appeared in Germany, Hungary, and Spain, different from indigenous hunter-gatherers, whereas Russia was inhabited by a distinctive population of hunter-gatherers with high affinity to a ~24,000 year old Siberian6 . By ~6,000-5,000 years ago, a resurgence of hunter-gatherer ancestry had occurred throughout much of Europe, but in Russia, the Yamnaya steppe herders of this time were descended not only from the preceding eastern European hunter-gatherers, but from a population of Near Eastern ancestry. Western and Eastern Europe came into contact ~4,500 years ago, as the Late Neolithic Corded Ware people from Germany traced ~3/4 of their ancestry to the Yamnaya, documenting a massive migration into the heartland of Europe from its eastern periphery. This steppe ancestry persisted in all sampled central Europeans until at least ~3,000 years ago, and is ubiquitous in present-day Europeans. These results provide support for the theory of a steppe origin of at least some of the Indo-European languages of Europe

Global prevalence and genotype distribution of hepatitis C virus infection in 2015 : A modelling study

Publisher Copyright: © 2017 Elsevier LtdBackground The 69th World Health Assembly approved the Global Health Sector Strategy to eliminate hepatitis C virus (HCV) infection by 2030, which can become a reality with the recent launch of direct acting antiviral therapies. Reliable disease burden estimates are required for national strategies. This analysis estimates the global prevalence of viraemic HCV at the end of 2015, an update of—and expansion on—the 2014 analysis, which reported 80 million (95% CI 64–103) viraemic infections in 2013. Methods We developed country-level disease burden models following a systematic review of HCV prevalence (number of studies, n=6754) and genotype (n=11 342) studies published after 2013. A Delphi process was used to gain country expert consensus and validate inputs. Published estimates alone were used for countries where expert panel meetings could not be scheduled. Global prevalence was estimated using regional averages for countries without data. Findings Models were built for 100 countries, 59 of which were approved by country experts, with the remaining 41 estimated using published data alone. The remaining countries had insufficient data to create a model. The global prevalence of viraemic HCV is estimated to be 1·0% (95% uncertainty interval 0·8–1·1) in 2015, corresponding to 71·1 million (62·5–79·4) viraemic infections. Genotypes 1 and 3 were the most common cause of infections (44% and 25%, respectively). Interpretation The global estimate of viraemic infections is lower than previous estimates, largely due to more recent (lower) prevalence estimates in Africa. Additionally, increased mortality due to liver-related causes and an ageing population may have contributed to a reduction in infections. Funding John C Martin Foundation.publishersversionPeer reviewe