基于三点插值的数值积分新算法及程序设计

本文利用三点插值函数近似表达被积函数,构造梯形求积公式和Simpson求积公式,并在此基础上提出了一种快速数值积分的新算法,即自适应步长三点插值型数值积分算法。该算法在按步骤处理节点的过程中,每步仅产生一个新节点,其它节点(老节点)都是以前各步产生的,因此可构成递推公式。本文还讨论了该算法的程序设计问题,并给出了程序设计框图。     

WASMOD模型参数敏感性与相关性分析

对水文模型参数进行敏感性和相关性分析,可以减少率定参数的数量、提高模型运行效率,并可以为优化和改进模型结构提供依据.本文采用局部分析法和相关系数法讨论了WASMOD模型中的五个参数对目标函数的敏感程度以及参数之间的相关程度.研究发现,在黑河流域上游山区的径流模拟过程中,WASMOD模型中影响降水形态的温度参数a1对目标函数最为敏感;其次是影响地表径流的参数a6和影响融雪过程的温度参数a2;基流参数a5最不敏感.模型参数之间的相关性不是很强,这也说明,模型结构已得到很好的优化;为保证模型的模拟效果,模型参数的数量不能减少.     

基于SEBAL模型的区域ET计算及气象参数敏感性分析

本文根据SEBAL模型的理论建立了利用遥感数据计算区域ET的计算模型,提出了敏感度评价指标,建立了单参数敏感性评价体系,并对模型气象参数进行敏感性评价。计算模型以Landsat7 ETM+遥感影像数据和大气温度、风速、湿度、日照时数等地表气象数据作为输入,并对一些难以获取的参数做了简化处理,以ERDAS Imagine遥感数据处理软件为工具,计算了研究区（天津市）24h ET空间分布图,并与Penman-Monteith公式所计算的研究区4种典型下垫面ET比较,结果显示,SEBAL模型计算的ET空间分布比较符合下垫面实际情况,计算结果较合理。考虑到气象数据对模型的影响重大,本文利用独立敏感度评价指标对模型中几个气象参数进行了敏感性分析,发现SEABL模型对风速、气温比较敏感,而对计算过程中选取的“热点”温度不敏感。本次建立的SEBAL模型计算较准确,参数敏感度评价方法简单有效,适合独立参数的敏感性分析。     

东海生物能量流动ECOPATH模型建立中的数据敏感性分析

ECOPATH模型是根据各生物功能组的能量输入与输出平衡,从而对生物资源能量流动进行静态评价.本文根据国际水生资源管理中心网站的东海区生物资源数据和历史文献资料数据,在建立包含32个功能组的东海区ECOPATH模型的过程中,从输入数据变化率(-50%～+50%)和估算数据变化率关系、输入数据生物量的变化率与估算数据生物量的变化率的关系以及输入数据生物量的变化率与估算数据生态转移效率的变化率关系三个方面,分析了东海区ECOPATH模型中数据的敏感性.发现输入数据变化率和估算数据变化率成e指数关系,在负值区间,数据的敏感性比正值区间的要大;不同功能组的输入数据生物量的变化率和估算数据生物量的变化率成线性正相关关系,斜率越大,敏感性越强;同功能组的输入数据生物量的变化率与估算数据生态转移效率的变化率成e指数关系,估算参数生态转移效率的变化率值的范围在-0.499～1.000之间;不同功能组的输入数据生物量的变化率与估算数据生态转移效率的变化率之间成线性正相关关系,斜率越大,敏感性越强.研究成果为东海区ECOPATH模型的建立,数据的选择和调整提供了科学依据.     

Rickety numbers: Volatility of university rankings and policy implications

The most popular world university rankings are routinely taken at face value by media and social actors. While these rankings are politically influential, they are sensitive to both the conceptual framework (the set of indicators) and the modelling choices made in their construction (e.g., weighting or type of aggregation). A robustness analysis, based on a multi-modelling approach, aims to test the validity of the inference about the rankings produced in the Academic Ranking of World Universities (ARWU) of Shanghai Jiao Tong University and those produced by the UK's Times Higher Education Supplement (THES). Conclusions are drawn on the reliability of individual university ranks and on relative country or macro regional performance (e.g., Europe versus USA versus China) in terms of the number of top performing institutions. We find that while university and country level statistical inferences are unsound, the inference on macro regions is more robust. The paper also aims to propose an alternative ranking which is more dependant on the framework than on the methodological choices.     

微车FR型动力传动系扭振特性及其控制方法评述

阐述动力传动系扭振分析的三种方法（理论分析、试验测试以及 CAE 仿真）,并分析微车 FR 型动力传动系扭振特性。在此基础上,从动力学参数优化和附加减、隔振装置两方面总结动力传动系扭振控制方法,具体包括动力学参数对传动系固有特性和扭振响应的影响分析和TVD、CTD、DMF、STD的优缺点对比以及工程应用现状讨论。     

基于GIS的干旱区土壤盐渍化敏感性评价——以渭干河-库车河三角洲绿洲为例

本文根据研究区域的自然环境特征,在GIS支持下,通过单因子分析和多因子综合评价相结合,对研究区域土壤盐渍化敏感性进行了评价,明确了土壤盐渍化敏感性分布规律及其地域差异。结果表明,研究区域土壤盐渍化危险性较严重—敏感性区域主要以中度敏感性、轻度敏感性为主,其中土壤盐渍化重度敏感区面积占绿洲总面积的15%,中度敏感区占31%,轻度敏感区占30%;不敏感区面积占35%;从整个研究区来看,盐渍化敏感性的分布呈现出以下特点：一是盐渍化危险性区域,尤其是中度、重度敏感区域呈大面积区域性分布,轻度敏感性区域呈片状或斑点状断续分布;二是盐渍化危险性东部高于西部,南部高于北部的趋势。     

高耗能行业CO2排放强度对生产技术变化的敏感性分析

"十一五"时期我国六大高耗能行业单位增加值能耗累计下降超过20%,研究高耗能行业CO2排放强度的敏感因素对实现2020年节能减排目标意义重大。本文首先对投入-产出模型在研究碳排放或能耗问题中的应用进行了整体的概述,将基于投入-产出模型的敏感性分析与相关方法进行比较,明确其优越性。然后,以我国2007年投入-产出表为数据基础,建立26部门的对称投入产出表,通过敏感性分析研究了不同行业生产技术变化对高耗能行业CO2排放强度的影响深度,得出结论:电力、热力生产和供应业技术系数变化对整体高耗能行业排放强度影响最为显著;大多数高耗能行业排放强度对本行业生产技术变化最为敏感;一般而言,直接生产技术系数变化带来的影响大于间接生产技术系数;考虑系数的结构相关性影响后,各高耗能行业排放强度普遍对关键技术系数的变化更为敏感。     

应用于低压省煤器的H型鳍片管传热分析

锅炉排烟温度过高会造成热损失,增设低压省煤器对于降低电厂排烟温度,提高电厂热经济性,保护空气预热器的安全运行具有重要意义。H型鳍片管是一种广泛应用于低压省煤器的换热元件。本文以一种H型鳍片管为例,通过数值模拟对其传热过程进行了分析,获得了H型鳍片管翅片侧表面传热系数和流动阻力随烟气流速和鳍片节距的变化规律。     

Research ethics in Internet-enabled research: Human subjects issues and methodological myopia

As Internet resources are usedmore frequently for research on social andpsychological behavior, concerns grow aboutwhether characteristics of such research affecthuman subjects protections. Early efforts toaddress such concerns have done more toidentify potential problems than to evaluatethem or to seek solutions, leaving bodiescharged with human subjects oversight in aquagmire. This article critiques some of theseissues in light of the US Code of FederalRegulations' policies for the Protection ofHuman Subjects, and argues that some of theissues have no pertinence when examined in thecontext of common methodological approachesthat previous commentators failed to consider. By separating applicable contexts from thosethat are not, and by identifying cases wheresubjects' characteristics are irrelevant and/orimpossible to provide, oversight committees maybe able to consider research applications moreappropriately, and investigators may be lessethically bound to ascertain and demonstratethose characteristics.     

The relationship between citation errors and library anxiety: An empirical study of doctoral students in education

The present study investigated whether levels of library anxiety predict simultaneously the citation error rate and quality of reference lists in doctoral dissertation proposals among 93 doctoral students in education. This study was unique for at least two reasons. First, it was one of the first studies to examine bibliographic citation inaccuracies in doctoral research proposals. Second, the current investigation was one of the first to investigate the psychological characteristics of doctoral students who commit such errors. A canonical correlation analysis revealed a multivariate relationship between levels of library anxiety and both the citation error rate and quality of reference lists. This finding suggests that level of library anxiety plays an important role in students’ ability to construct accurate reference lists. The implications of these findings are discussed.     

天津近海风能资源的高分辨率数值模拟与评估

风能是可再生能源中发展最快的清洁能源,具有广阔的应用前景。近海地区由于风速较大,以及可利用面积大等优点,近海风电是未来风电发展中一种新的趋势,但海上气象要素直接观测困难,需要通过高分辨率数值模拟对其可利用性及开发潜力进行评估。本文利用MM5/Calmet模式模拟了天津沿海地区的较高分辨率（水平分辨率1km×1km、垂直分辨率10m）的风能资源分布状况,并结合实测数据对其模拟效果进行了评估。结果表明：该模式对天津沿海地区的年平均风速及风速的逐日变化趋势均具有良好的模拟能力,3个测风塔年平均风速的相对误差分别为7.11%、12.99%、6.14%,可为天津海上风能资源评估提供科学依据;利用风速大小年景分析得到天津沿m2,海且地有区效多小年时平数均长风,风能资资源源状分况布较状好况。,发现天津近海海域年平均风速在（6.6~7.0）m/s,平均风功率密度超过340w/m~2,且有效小时数长,风资源状况较好。     

固定挡铁和活动挡铁配合装夹法在数控加工中的应用

本文通过对固定挡铁和活动挡铁配合装夹方法的研究及实践,提出解决细长形状且型面复杂的模具加工时的装夹方案。通过控制变形,优化装夹步骤,提高数控加工效率,从而缩短工装制造周期,提升工装制造质量。     

中国陆地水系统数值模拟与综合集成研究平台建设

面向国家水资源综合研究的需求,本文提出了建设中国水系统数值模拟和综合集成研究平台的方案,包括水资源科学数据库、水系统数值模拟平台、水资源数据和产品的真实性检验系统、基于网络的水系统协同应用环境、水资源综合决策支持系统和水资源数据、产品服务与发布系统六大部分。中国水系统数值模拟和综合集成研究平台建设的总体目标即是通过对水资源数据、模型、知识的综合集成,利用计算机和网络的先进技术,引入水系统协同研究的新理念,搭建起可以满足不同部门和人员需要的开放式的水资源研究和应用平台,服务于不同部门和机构,不同层次科研人员、管理人员乃至社会公众研判、决策的水资源科学数据和产品,从而推动水资源科学综合研究和应用的全面发展,起到为国家重大水问题、水工程研究和决策,为国家水资源安全和发展战略制定提供基础科技支撑和科技保障的作用。     

Supporting multiple paths to objects in information hierarchies: Faceted classification,faceted search,and symbolic links

We present three fundamental, interrelated approaches to support multiple access paths to each terminal object in information hierarchies: faceted classification, faceted search, and web directories with embedded symbolic links. This survey aims to demonstrate how each approach supports users who seek information from multiple perspectives. We achieve this by exploring each approach, the relationships between these approaches, including tradeoffs, and how they can be used in concert, while focusing on a core set of hypermedia elements common to all. This approach provides a foundation from which to study, understand, and synthesize applications which employ these techniques. This survey does not aim to be comprehensive, but rather focuses on thematic issues.     

平面构成教学现状的分析与改进措施

平面构成是一门培养艺术设计人员的重要课程。目前在我国部分高校教学中却存在着一些弊端,如教学方法陈旧和教学手段单一、重模仿而轻创新,没有真正把平面设计的能力培养放在首要位置上等。分析了这些弊端产生的原因并有针对性地提出了一系列的教学改革措施,包括采用启发式和互动式教学方式、重视创新性思维能力的培养、结合现代化教学手段等,强调重视学生综合设计思维能力的培养,力求全面提升平面构成的教学质量。     

Research quality and efficiency: An analysis of assessments and management issues in Dutch economics and business research programs

Assessments of quality and productivity of academic research programs become more and more important in gaining financial support, in hiring and promoting research staff, and in building academic reputation. Most assessments are based on peer review or on bibliometric information. In this paper we analyze both bibliometric data and peer review assessments of 169 research groups in economics, econometrics and business administration. The evaluations are achieved in two independent rounds in 1995 and in 2001, permitting replication of our study.The purpose of this study is twofold. In the first part we want to see to what degree bibliometric information relates to peer review judgments. The results convey how evaluators weight different output categories in their final overall judgment of academic quality. The results also have practical meaning, since they indicate what the predictive ability of bibliometric data is for future peer review outcomes. In the second part of this study we aim at explaining differences in research output quality and productivity by organizational factors, like size of the research group, composition of staff, sources of research funding and academic discipline. In this part, a composite indicator is used to represent the review committees’ overall assessment. The bibliometric data most strongly related to the peer reviews’ overall assessment are used to construct data envelopment analyses’ efficiency scores as measure of research productivity.The main conclusions from our study are that the number of publications in international top journals is the best predictor of peer review assessment results. Changes in the classification of bibliometric information, as introduced in the second evaluation round, do not alter this conclusion. Size of the research group appears to be the only permanent characteristic associated with research quality and productivity. Size is positively related to research quality but negatively related to research productivity. Larger groups appear to have the potential to improve quality, but as groups become larger, they also experience problems in maintaining the research productivity of the research team's members. The remaining organizational characteristics appear to be temporarily related to research quality and productivity. In the first evaluation round, research productivity and quality are associated with the discipline variable: research programs in more quantitative areas and characterized by a higher level of paradigm development like econometrics and operations research achieved higher levels of research quality and productivity than programs in more diverse and less quantitative areas like business administration. This relation however is not permanent, since it becomes insignificant in the second evaluation round. Instead, funding relations become more apparent in the second review round. The relative amount of national funding in the research group's funding becomes positively related to academic quality, whereas the portion of income from committed research is negatively related to academic quality of the programs’ research output. This may have been caused by the increased importance of alternative sources of research funding in the period of the second review.     

Fuzzy-set Qualitative Comparative Analysis (fsQCA): Guidelines for research practice in Information Systems and marketing

The increasing interest in fuzzy-set Qualitative Comparative Analysis (fsQCA) in Information Systems and marketing raises the need for a tutorial paper that discusses the basic concepts and principles of the method, provide answers to typical questions that editors, reviewers, and authors would have when dealing with a new tool of analysis, and practically guide researchers on how to employ fsQCA. This article helps the reader to gain richer information from their data and understand the importance of avoiding shallow information‐from‐data reporting. To this end, it proposes a different research paradigm that includes asymmetric, configurational‐focused case‐outcome theory construction and somewhat precise outcome testing. This article offers a detailed step-by-step guide on how to employ fsQCA by using as an example an already published study. We analyze the same dataset and present all the details in each step of the analysis to guide the reader onto how to employ fsQCA. The article discusses differences between fsQCA and variance-based approaches and compares fsQCA with those from structured equation modelling. Finally, the article offers a summary of thresholds and guidelines for practice, along with a discussion on how existing papers that employ variance-based methods are extendable and complemented through fsQCA.     

大数据环境下情报学方法与技术体系构建

【目的/意义】为大数据环境下情报学的研究提供方法、技术和应用过程的参考。【方法/过程】应用特征分析法、文献分析法和系统开发方法,对大数据环境下情报学方法与技术体系进行了特点、方法和应用过程的研究。分析了大数据环境下情报学研究发生的演变,根据这些变化,指出了大数据环境下情报学的研究思路,从文献分析、Web数据分析和综合分析三类梳理了情报学研究的方法与技术,并分别给出了这些方法和技术的应用过程。【结果/结论】通过方法与技术的梳理发现,大数据环境下情报学的研究是以数据为中心的、多种技术综合应用的科学研究过程。