s-grams: Defining generalized n-grams for information retrieval

n-grams have been used widely and successfully for approximate string matching in many areas. s-grams have been introduced recently as an n-gram based matching technique, where di-grams are formed of both adjacent and non-adjacent characters. s-grams have proved successful in approximate string matching across language boundaries in Information Retrieval (IR). s-grams however lack precise definitions. Also their similarity comparison lacks precise definition. In this paper, we give precise definitions for both. Our definitions are developed in a bottom-up manner, only assuming character strings and elementary mathematical concepts. Extending established practices, we provide novel definitions of s-gram profiles and the L₁ distance metric for them. This is a stronger string proximity measure than the popular Jaccard similarity measure because Jaccard is insensitive to the counts of each n-gram in the strings to be compared. However, due to the popularity of Jaccard in IR experiments, we define the reduction of s-gram profiles to binary profiles in order to precisely define the (extended) Jaccard similarity function for s-grams. We also show that n-gram similarity/distance computations are special cases of our generalized definitions.     

Managing misspelled queries in IR applications

Our work concerns the design of robust information retrieval environments that can successfully handle queries containing misspelled words. Our aim is to perform a comparative analysis of the efficacy of two possible strategies that can be adopted.     

医学论文中成组t检验P值错误及其原因分析

【目的】 调查医学论文中成组t检验的P值错误,分析错误原因,并提出相应措施。【方法】 选取236种医学期刊,每种期刊选取1项成组t检验,核验其P值,应用χ²检验、Mantel-Haenszel法、二项式logistic回归分析P值错误。【结果】 236项成组t检验中,50项存在P值错误。单因素分析结果显示,核心期刊与非核心期刊相比,P值错误发生率差异具有统计学意义(χ²=4.871,P=0.027);给出具体P值组与未给出具体P值组相比,P值错误发生率差异具有统计学意义(χ²=15.440,P<0.0001)。将是否给出具体P值作为混杂因素,比较核心期刊与非核心期刊P值错误发生率,差异无统计学意义(χ²=2.703,P=0.100)。多因素分析结果显示,是否方差齐(OR值为0.470,95%CI为0.230~0.961)、是否给出具体P值(OR值为5.459,95%CI为2.311~12.895)具有统计学意义。【结论】 医学论文成组t检验P值错误较多。为及时发现P值错误,期刊编辑应当重视对统计学方法应用条件的审查,要求作者给出统计描述以及统计推断的具体结果,能够利用简单易学的统计学软件核实P值。     

Domain analysis and information retrieval through the construction of heliocentric maps based on ISI-JCR category cocitation

We propose the use of ISI-JCR categories as units of cocitation and measurement for the construction of heliocentric maps. The use of a spatial metaphor allows us to illustrate, analyze and compare domains in terms of the categories and their interconnections or links. We can also move around within the structure of these domains for further analysis, and access the documents associated to the categories and to the links that cocite or relate them.     

Cerebrospinal fluid free sialic acid and aspartate transaminase levels in meningitis

Background  Sialic acid (SA) is a nine carbon sugar derived from mannosamine and pyruvate. High levels of sialic acid and aspartate transaminase (AST) levels in cerebrospinal fluid have been described in pyogenic meningitis (PM) compared to tubercular meningitis (TBM). Objectives  To evaluate the levels of CSF free SA in PM and TBM and to assess the correlation between CSF free SA and CSF glucose or total protein levels. Patients and Methods  A total of 122 subjects were studied and divided into children and adults. Further, these have been subdivided into controls, PM and TBM. CSF free SA was estimated by thiobarbituric acid assay of Warren and AST by Reitmann and Frankel method. Results  CSF free SA and AST levels in children and adults were significantly high in PM (p<0.001) as compared to TBM and controls. Conclusion  A very high CSF free SA and AST were found to be characteristic of PM, making them useful parameters to differentiate PM from TBM.     

Nepotistic relationships in Twitter and their impact on rank prestige algorithms

Micro-blogging services such as Twitter allow anyone to publish anything, anytime. Needless to say, many of the available contents can be diminished as babble or spam. However, given the number and diversity of users, some valuable pieces of information should arise from the stream of tweets. Thus, such services can develop into valuable sources of up-to-date information (the so-called real-time web) provided a way to find the most relevant/trustworthy/authoritative users is available. Hence, this makes a highly pertinent question for which graph centrality methods can provide an answer. In this paper the author offers a comprehensive survey of feasible algorithms for ranking users in social networks, he examines their vulnerabilities to linking malpractice in such networks, and suggests an objective criterion against which to compare such algorithms. Additionally, he suggests a first step towards “desensitizing” prestige algorithms against cheating by spammers and other abusive users.     

The effect of user characteristics on search effectiveness in information retrieval

This paper investigates the influence of user characteristics (e.g. search experience and cognitive skills) on user effectiveness. A user study was conducted to investigate this effect, 56 participants completed searches for 56 topics using the TREC test collection. Results indicated that participants with search experience and high cognitive skills were more effective than those with less experience and slower perceptual abilities. However, all users rated themselves with the same level of satisfaction with the search results despite the fact they varied substantially in their effectiveness. Therefore, information retrieval evaluators should take these factors into consideration when investigating the impact of system effectiveness on user effectiveness.     

基于MODIS数据的泰国林地资源提取

遥感技术的发展为我们对世界资源的研究提供了新的手段,克服了世界资源研究过程中数据缺乏的困难。泰国曾经是林地资源丰富的国家,尤其是热带林地资源,但是近几十年来林地面积在不断减少,带来了一系列生态问题。选用MOD09Q1的1、2波段,MOD09A1的第6波段以及MOD11A2数据产品提取了泰国林地分布情况。由于泰国地处热带地区云雾噪音为林地的提取造成了很大的不确定性,为了有效去除云雾噪音影响,结合NDVI、NDSI、LST多参数在林地提取中的优势对泰国林地进行提取。采用泰国2003年统计年鉴提供的分省林地面积以及2003年p131r47和p131r48共2景ETM影像进行了精度验证。结果表明,利用多参数综合分类方法对林地提取精度较高,通过与2003年统计年鉴数据进行回归分析发现二者存在明显的线性关系,决定系数达到0.9264。     

Sticky information and heterogeneous needs as determining factors of R&D cooperation with customers

The aim of this work is to investigate the factors determining cooperation in developing innovations between firms and a specific group of agents, customers and users. The central point of the analysis is two variables recognised in previous studies as important factors in the study of cooperation with these agents, but which basically have been dealt with from a purely theoretical viewpoint. These variables are: (1) the existence of sticky information (information which is costly to obtain, transfer and use) and (2) the presence of heterogeneous needs in the market. Regarding the first variable, we have also taken into account two kinds of information which can be sticky: information on needs and information of technological nature. The findings obtained, using a Spanish sample of firms, show clearly that all these three factors exert a positive influence on cooperative relationships with these agents.     

Effect of<Emphasis Type="Italic">Vitex negundo</Emphasis> leaf extract on the free radicals scavengers in complete Freund's adjuvant induced arthritic rats

The effect of the oral administration ofVitex negundo leaf extract on the levels of enzymic and non-enzymic antioxidants were studied in the adjuvant induced arthritic (AIA) rats The levels of antioxidant enzymes such as SOD, CAT, GPx, G6PD, GSH and Vit-C were estimated in various groups of the experimental rats. It was observed that the antioxidant enzyme levels in the AIA were significantly low when compared to normal rats. A significant decrease in enzymic antioxidant—SOD, CAT, GPx, G6PD and non-enzymic antioxidant—GSH, Vit-C were observed in the liver of AIA rats compared to the normal rats. These results suggest that the leaf extract ofVitex negundo possesses antioxidant activity.     

Changes to university IPR regulations in Europe and the impact on academic patenting

This article develops a general framework to describe the changes in university IPR regulations in Europe and their effects on the patenting activities of universities and on knowledge transfer processes. Understanding the effects of changes in IPR regulations on academic patenting is a complex issue, and parallels with the US case can be misleading. First, despite the general trend towards institutional ownership, university IPR regulations in Europe remain extremely differentiated and there is no one-to-one mapping to the US system. Second, it is difficult to disentangle the quantitative and qualitative effects of changes in IPR ownership regulations on academic patenting activities from the effects of concurrent transformations in the institutional, cultural and organizational landscape surrounding academic knowledge transfer. The article proposes a review and typological classification of national university IPR ownership systems on the basis of their development since 2000, and uses it to analyze the aggregate dynamics of academic patent ownership in several European countries. The analysis of patterns of ownership of academic patents shows that there has been a general increase in university patenting since 1990, with a significant slowdown (and even reduction in some countries) after early 2000s accompanied by a switch in academic patents ownership in favor of university ownership though preserving the European specificity of high company ownership of academic invented patents.     

Antitubercular activity of garlic (allium sativum) extract on combination with conventional antitubercular drugs in tubercular lymphadenitis

Based on our demonstration earlier that ethanol extract, water extract and a compound purified from garlic possessedin vitro antitubercular activity against drug resistant and susceptibleMycobacterium tuberculosis, we tried the effect of garlic extract in 30 patients of tubercular lymphadenitis. For ethical considerations, two groups of patients, 30 each, were given antitubercular therapy (ATT) consisting of isoniazid, rifampicin, ethambutol and pyrazinamide for 30 days. For the next 15 days (31 to 45 days) group 1 patients received 3–6 garlic pearls per day in addition to ATT while group 2 patients received ATT only. From 46th day onwards both the groups received ATT only for 6–8 months. Antitubercular activity of the serum samples collected on 45th day was assessed by its effect on the growth ofM. tuberculois. The serum of group 1 patients showed significantly much higher antitubercular activity than that of group 2 patients. Further, there was relief of dyspeptic symptoms caused by ATT therapy in patients of group 1 with garlic plus ATT therapy but no change in group 2 patients with ATT only. Liver function and hematological tests were normal in both the groups after 6 months of therapy. Garlic extracts or compounds have a good potential as antitubercular(s) drug if given as a supplement to ATT.     

国外四大医学期刊富媒体数字内容开发现状及对国内医学期刊的启示

【目的】 探讨我国医学期刊在富媒体数字内容开发方面的有效路径。【方法】 以《新英格兰医学杂志》《柳叶刀》《美国医学会杂志》《英国医学期刊》四大医学期刊网站富媒体数字内容为主要调研对象,结合国内医学期刊现状以及笔者所在编辑部实践情况,分析探讨我国医学期刊富媒体数字内容开发现状。【结果】 随着数字化出版革命的不断演进,富媒体内容已经成为四大医学期刊数字内容增值服务的重要部分,具有如下特点：均较早地引入专家视频、音频访谈内容;越来越多的文章以富媒体形态出版;对期刊学术资源进行二次加工,推出多种交互式产品;出现视频形态的“文章”;信息图得到广泛应用;部分资源通过付费订阅等方式开辟新的营收途径。国内医学期刊数字化发展还处于初级阶段,富媒体内容开发能力薄弱,应当从加强集约化经营、重视专门人才的引进以及培养、充分发掘自身特色资源等方向入手,增强富媒体内容的开发能力。【结论】 国内医学期刊应当学习借鉴四大医学期刊在富媒体内容开发方面的先进经验,结合实际情况和自身特色,提高富媒体内容开发能力,更好地促进学术影响力的提升,创造更大的社会效益和经济效益。     

The impact of entrepreneurial capacity, experience and organizational support on academic entrepreneurship

Although sources and determinants of academic entrepreneurship have begun to command the attention of policy-makers and researchers, there remain many unanswered questions about how individual and social factors shape the decisions of academics to engage in entrepreneurial activities. Using a large-scale panel of academics from a variety of UK universities from 2001 to 2009, this paper examines how an academics’ level of entrepreneurial capacity in terms of opportunity recognition capacity, and their prior entrepreneurial experience shape the likelihood of them being involved in starting up a new venture. In addition, we explore what role university Technology Transfer Offices (TTOs) play in stimulating venture creation. The results show that individual-level attributes and experience are the most important predictors of academic entrepreneurship. We also find that the social environment surrounding the academic also plays an influential role, but its role is much less pronounced than individual-level factors. Finally, we show that the activities of the TTO play only a marginal, indirect role, in driving academics to start new ventures. We explore the implications of this analysis for policy and organizational design for academic entrepreneurship.     

《医学信息检索与利用》课程PBL-LBL教学方法改革探讨

针对《医学信息检索与利用》这门课程在我校各医学专业教学的现状与问题,将PBL与LBL相结合的教学法引入教学中,既提高了教师的自身素质,又培养了学生的自主学习能力,形成教学相长的良好循环。     

Limiting GPR in a two-layer soil model via genetic algorithms

In this paper, an optimum grounding grid that provides the conditions of GPR<E_touch and minimum cost in the structures of two-layer soil model is designed and the length of total conductor and the quantity of ground rod are calculated via Genetic Algorithms (GA). A new approach is presented for the calculation of total conductor length. At the same time, the subject regarding in which layer the ground conductors and rods that form the grounding grid in a substation are to be placed in two-layer soil is analysed using GA. With this as the goal, the depth of optimum grid burial is determined. Our study is compared with the design study for a two-layer soil model in the literature. As a result, the high performance of optimum grid design that is achieved using GA is emphasized by varied applications.     

基于SWOT分析的科技期刊精品化发展战略——以《热带地理》近年办刊实践为例

【目的】 基于《热带地理》近年办刊实践,探讨科技期刊的精品化发展战略,为科技期刊在实践操作方面提供参考。【方法】 以精品意识作为办刊理念,以SWOT模型作为分析思路,对《热带地理》当前办刊面临的外部机遇和挑战、本身所具有的优势和劣势进行全面分析。【结果】 抓住热点组织专题、转变地域限制为地域特色、增设“学术争鸣”栏目是《热带地理》实施精品化、特色化发展的战略措施,在提升期刊核心竞争力方面起到了切实可行的拉动作用,带动期刊飞跃发展;摸索出一条确保专题高质量出版的创新模式：精选专题主题→发布征稿启事或邀稿函→专题参与者提交文章题目→举办专题中期研讨会或圆桌论坛→专题出版→专题有效传播。【结论】 期刊应该精准分析自身的发展机遇,充分利用自身存在的优势,有效转变劣势,有针对性地制定科学可行的精品化发展战略,这是提升期刊竞争力的有效途径。     

科技期刊封面图文信息的视觉传播研究——以《科学美国人(国际版)》为例

【目的】 探究《科学美国人(国际版)》封面图文信息的视觉传播特点,为我国科技期刊封面设计迈向精品化与国际化提供借鉴。【方法】 从社会符号学的视角出发,运用多模态话语分析理论,采用定量与定性分析相结合的研究方法,对2006—2016年该期刊129幅封面图文关系进行信息传播的解读与分析。【结果】 在理论应用过程中对原理论进行补充和修正,同时弥补了社会符号学和视觉传播双重视域下科技期刊封面的研究缺憾,为我国科技期刊的封面设计提供另类思路。【结论】 科技期刊应树立、坚守期刊品牌的视觉形象,注重文字模态和图像模态的相互配合,使封面科学信息的视觉传播效果最大化和最优化。     

顶级期刊的高网络参与度论文分析

【目的】 考察顶级期刊的影响力,总结顶级期刊高网络参与度论文的特征,为我国科技期刊评价和科学传播提供借鉴。【方法】 以Nature 2016年高网络参与度论文为分析对象,选取Scopus、Altmetric.com进行文献被引频次及Altmetrics指标采集,对高网络参与度论文作者、学科、收录引用文献类型、Nature的IF和CiteScore、Altmetrics指标的覆盖率进行统计分析。【结果】 Nature高网络参与度论文的合著率达52%;各学科分布相对均衡,人文社会科学成果占19%;Scopus对Nature的论文选择性收录,仅从本研究来看,News的收录仅占28.97%;Nature同年度CiteScore比IF数值低;Blog、Facebook、Tweeter、Google+、Reddit、Mendeley、news story覆盖率较高,可用于探讨顶级科研成果在网络上的关注程度及其传播规律。【结论】 Nature与国际在线发布平台合作服务的新型出版模式在一定程度上成就了高网络参与度论文。     

Acta Materialia的办刊之道及对我国科技期刊的启示

【目的】 探索材料冶金领域国际一流期刊Acta Materialia的办刊策略,为提升我国科技期刊的学术质量和影响力提供参考。【方法】 以Acta Materialia为研究对象,通过文献查阅和数据库统计,分析了Acta Materialia享有较高学术地位和学术威望的原因,总结其办刊特色和运行机制,得出对我国科技期刊的启示,并将其应用于《材料科学技术(英文版)》(Journal of Materials Science & Technology,JMST)的办刊实践中。【结果】 坚持办刊特色和内容高质量的方针、全球化的办刊视野和编辑出版分离的办刊模式是Acta Materialia取得成功的重要因素,将其运行机制应用到JMST的办刊实践中,编辑出版分离、缩短稿件发表周期、提高编辑队伍素质和建立国际专业的编辑体系等措施能够显著提高JMST的办刊能力和期刊影响力。【结论】 针对我国科技期刊存在的问题,将国外优秀期刊的成功办刊模式和经验应用到办刊实践中,可以显著提升我国科技期刊对优质稿件的吸引力,从而提高期刊影响力,打造国际精品期刊。