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An Improved heapsORT Algorithm with nlogn-0.788928n Comparisons in the Worst Case

Journal of Computer Science & Technology 2007年第6期22卷 898-903页

作者：王晓东吴英杰 College of Mathematics and Computer Science Fuzhou University

A new variant of heapsORT is presented in this paper. The algorithm is not an internal sorting algorithm in the strong sense, since extra storage for n integers is necessary. The basic idea of the new algorithm is similar to the classical sorting algorithm heapsORT, but the algorithm rebuilds the heap in another way. The basic idea of the new algorithm is it uses only one comparison at each node. The new algorithm shift walks down a path in the heap until a leaf is reached. The request of placing the element in the root immediately to its destination is relaxed. The new algorithm requires about n log n - 0.788928n comparisons in the worst case and n log n - n comparisons on the average which is only about 0.4n more than necessary. It beats on average even the clever variants of QUICKSORT, if n is not very small. The difference between the worst case and the best case indicates that there is still room for improvement of the new algorithm by constructing heap more carefully.

关键词： data structures analysis of algorithms heaps heapsORT

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Protection of groundwater from migration of infiltrates from a chromic waste storage site and methods of treating these infiltrates

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Health 2010年第3期2卷 177-187页

作者： Zygmunt Kowalski Adam Kozak Marcin Banach Agnieszka Makara Cracow University of Technology zkow@chemia.pk.edu.pl

This work presents the results of investigations to develop and implement methods to effectively collect and purify infiltrates from heaps, situated in the region of Alwernia near Cracow, where more than 3 million tonnes of waste material resulting from the production of chromium compounds have been stored. It describes a system for the protection of groundwater from these infiltrates which contain 50-400 g m-3 Cr6+, as well as the effectiveness of cheap and simple chemical methods to purify these chromic wastewaters. The infiltrate collection system and the most effective method to decrease the concentration of Cr6+ to a level below 0.1 ppm, as required by Polish and European Union regulations, were implemented in the Alwernia Chemical Works S. A. in the years 1998-1999.

关键词： Waste heaps Chromic Infiltrates Collect Purify

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Properties of Soils of Abandoned Coal Mine Industrial Areas (Primorsky Krai, Russia)

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Journal of Geoscience and Environment Protection 2018年第6期6卷 78-92页

作者： Olga D. Arefieva Valentina G. Tregubova Natalya V. Gruschakova Valerij T. Starozhilov Far Eastern Federal University Vladivostok Russian Federation

Lipovtsy coal field mine №4 processed north-western reserves of Lipovtsy field in Primorski Krai (Russia). In 1997, the mine was declared unprofitable and was abandoned by natural flooding with no arrangement of mine water discharge and in 2005 it was fully flooded. The main sources of pollution in the studied area are spoil heaps (mine wastes), underspoil filtering waters and mine waters which are being discharged on the surface after finishing of “hydraulic funnel” artificial support. The study of technogenic landscape of abandoned mine industrial area showed that its morphologic form is dominated by spoil heaps. Soils located near mine waste body differ from benchmark soils by chemical properties and size distribution. The influence of active hydrochemical mine and drainage water flows is the reason of the above-mentioned variation in soil properties. Results showed that, there exist a high correlation ratios between chemical composition of mine waters and water extracts from soil: Between the alkalinity of mine waters and electrical conductivity of soil water extracts (r = 0.73), between mine water iron content and pH of soil water extract (r = −0.56), between the solid residue of mine waters and electrical conductivity of soil water extracts (r = 0.72), between the mine waters calcium content and electrical conductivity of soil water extracts (r = −0.75), between the alkalinity of mine waters and silicon dioxide content of soil water extracts (r = 0.61), between the mineralization of mine waters and chrome content of soil water extracts (r = 0.73).

关键词： Luvisols Gleysols Spoil heaps Abandoned Coal Mines Heavy Metals

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大规模中文搜索引擎的用户日志分析

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华南理工大学学报（自然科学版） 2004年第Z1期32卷 1-5页

作者：王继民陈翀彭波北京大学信息科学技术学院北京100871

北大"天网"是一个大规模分布式搜索引擎系统.文中对其用户日志进行了分析和研究.结果显示:用户对系统的访问时间并不均等,一天中早晨、下午和晚上各出现一个波峰;通常用户在一天内只进行1-2次内容不同的查询,多于2／3的用户点击了结果... 详细信息

北大"天网"是一个大规模分布式搜索引擎系统.文中对其用户日志进行了分析和研究.结果显示:用户对系统的访问时间并不均等,一天中早晨、下午和晚上各出现一个波峰;通常用户在一天内只进行1-2次内容不同的查询,多于2／3的用户点击了结果页面中的某些网址(URL);多数用户输入的查询串中只含有一个词项并且包含中文字符,其中以2-4个汉字居多;用户查看结果页面的时间大约是2-3min;只有少数用户查看历史网页(或称网页快照).用户日志中不同查询串、不同用户和点击不同URL的数量满足heaps定律.

关键词：搜索引擎用户日志用户行为 heaps 定律

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