Practical algorithms for transposition-invariant string-matching

We consider the problems of (1) longest common subsequence (LCS) of two given strings in the case where the first may be shifted by some constant (that is, transposed) to match the second, and (2) transposition-invariant text searching using indel distance. These problems have applications in music comparison and retrieval. We introduce two novel techniques to solve these problems efficiently. The first is based on the branch and bound method, the second on bit-parallelism. Our branch and bound algorithm computes the longest common transposition-invariant subsequence (LCTS) in time O((m²+loglogσ)logσ) in the best case and O((m²+logσ)σ) in the worst case, where m and σ, respectively, are the length of the strings and the size of the alphabet. On the other hand, we show that the same problem can be solved by using bit-parallelism and thus obtain a speedup of O(w/logm) over the classical algorithms, where the computer word has w bits. The advantage of this latter algorithm over the present bit-parallel ones is that it allows the use of more complex distances, including general integer weights. Since our branch and bound method is very flexible, it can be further improved by combining it with other efficient algorithms such as our novel bit-parallel algorithm. We experiment on several combination possibilities and discuss which are the best settings for each of those combinations. Our algorithms are easily extended to other musically relevant cases, such as δ-matching and polyphony (where there are several parallel texts to be considered). We also show how our bit-parallel algorithm is adapted to text searching and illustrate its effectiveness in complex cases where the only known competing method is the use of brute force.     

《西北学术》的科技内容及其主旨

运用科学史研究方法，对《西北大学学报》的前身之一《西北学术》的科技史价值和办刊宗旨进行讨论。认为该刊为20世纪40年代西北大学的最高学术论坛，其有关西北国防化、西北学术思想、西北地理、西北物理学会的研究和活动等内容，突出了西北大学的区域特色。     

上天入地：思想史的边界与方法

思想史的研究方法与研究对象有十分密切的关系。通常情况下,研究对象多少已经决定了合宜的方法。甚至可以说,合宜的方法内在于对象,至少是内在于主体和对象的关系。思想史的研究有两条边界,一条是向上的通向哲学、形而上精神的世界;另一条是向下深挖的通向社会的、形而下生活的世界。思想史的这两条边界决定了思想史研究的主要方法取向。     

The many facets of linear programming

We examine the history of linear programming from computational, geometric, and complexity points of view, looking at simplex, ellipsoid, interior-point, and other methods. Received: June 22, 2000 / Accepted: April 4, 2001?Published online October 2, 2001     

单循环赛赛程安排的一个图论方法

利用图论的边着色理论建立了一个赛程安排的数学模型 .首先建立 n支球队与完全图 Kn的 n个顶点间的一一对应 ,把球队 Ai和 Aj间的比赛关系抽象成 Kn的顶点 i和 j间的边 ( i,j) .然后分别构造出了图K2 m- 1和 K2 m的正常 2 m-1边着色 .从而给出了各球队每两场比赛间得到的休整时间最均等 ,休整的间隔场次数达到上限值 n2 的一个赛程安排方案     

Constructing Space for Science at the Royal Institution of Great Britain

Those who have worked in the Royal Institution of Great Britain have, since its foundation in 1799, made significant contributions to scientific knowledge, to its practical application, and to its communication to a wide variety of audiences. Such work cannot be carried out in an architectural vacuum, and in this paper we examine how the buildings of the Royal Institution, 20 and 21 Albemarle Street in central London, have shaped the work undertaken within its walls and how, on a number of occasions, the buildings have been reconfigured to take account of the evolving needs of scientific research and communication. This paper is based on the Conservation Plan of the Royal Institution that we wrote during 2003. The Conservation Plan did not examine the land owned by the Royal Institution to the north (i.e., 22 and 23 Albemarle Street; for this area see Richard Garnier, “Grafton Street, Mayfair,” Georgian Group Journal 13 (2003), 210–272), but it did discuss 18 and 19 Albemarle Street. In this paper we concentrate on the core Royal Institution buildings at 20 and 21 Albemarle Street. Other studies of the relationship of architecture,space, and science include Crosbie Smith and Jon Agar, ed., Making Space for Science: Territorial Themes in the Shaping of Knowledge (Basingstoke: Macmillan, 1997); Peter Galison and Emily Thompson, ed., The Architecture of Science (Cambridge, Mass.: MIT Press, 1999); and Sophie Forgan,“The architecture of science and the idea of a university,” Studies in History and Philosophy of Science 20 (1989), 405–434. Frank A.J.L. James is Professor of the History of Science at the Royal Institution; he has written widely on the history of nineteenth-century science in its social and cultural contexts and is editor of the Correspondence of Michael Faraday. He is President of the British Society for the History of Science. Anthony Peers is an Associate of Rodney Melville and Partners where he works in the field of building conservation as an architectural historian. He is a Council member of the Ancient Monument Society.     

中国数学史断代研究的一项新成果：—《明清数学史论文集》简介

本文简介梅荣照主编的《明清数学史论文集》一书，对中国数学史开展断代专题研究，是我国数学史界继承并发展李俨、钱宝琮、严郭杰先生研究成果的宏大计划，持续近三十年，历来为国际科学史界所重视，文集收入论文15篇、附录2篇，其中严敦杰先生遗作7篇，本文对15篇论文逐一作了简介。     

地域的履历——浙江省奉化县忠义乡（下）

(接上期)上面提到的非定居移住民,是指从福建及浙江省南部的台州府等地流入奉化县山区的人,即所谓的“棚民”。在位于忠义乡以西的剡源乡,可以见到如下的记事 。剡源向乏水患,亦无劫案。自嘉庆初,闽、台(福建省与浙江省台州府———引用者)棚民相率来剡〔源乡〕,种靛青、种苞芦,日辟日广。如牛山之濯濯水,无所蓄迨。〔嘉庆〕末年,大雨连旬,山水骤注于溪,溪不能容,遂漂没田畴无算。……比年仙居、黄岩无业贫民偕来工作,寓居山厂,一不得食,抢劫之案,层见叠出。由此来看,自嘉庆初年( 1 8世纪末)以降,福建等地的棚民、浙江南部的贫民流入该地山…     

架起传统与现代的桥梁--建筑历史与理论课程体系教学改革的思考

重新审视建筑历史理论教学的目标、内容、教学方式和手段，通过对国内几座有影响的建筑院校的调研，比较各个院校在这些问题及途径上的异同，分析其利弊，以期促进建筑历史与理论课程体系教学的建设和改革．     

高校研究生论文答辩系统的设计

介绍了高校研究生论文答辩系统的核心算法,并给出了一种处理冲突的方法——专家相关回溯法。