基于TM影像的城市热岛效应和植被覆盖指数关系研究

通过对杭州市区ETM 遥感影像数据的处理,提取该区域地表亮温和NDVI数据,并结合实测温度对亮温数据的可靠性进行了验证。在亮温图的基础上,利用温度分级掩膜运算得出不同温度像元NDVI信息,同时对亮温数据进行了标准化处理,从而得到热岛强度和NDVI关系的散点图,然后利用监督分类、相关性矩阵及统计分析等方法,对关系数据进行了修改、验证及拟合,得出杭州市区热岛强度和NDVI之间的定量关系模型,修正判定系数达到0.88,较好地反映了该区域热岛效应和植被覆盖指数的关系,为杭州市城市规划、绿地规划等提供了较为可靠的理论依据。     

全文检索研究

A new algorithm for automatic segmentation of Chinese word with the stop word list and post-controlled thesaurus, that has absorbed the ideas from the single-Chinese character method and the thesaurus method, is given. Based on this algorithm, a new full text retrieval mode is built.     

Mathematical model of time-effective information retrieval system based on the theory of fuzzy sets

Search patterns of documents and information requests are their better or worse representatives only, so it is important to carry on examinations on possibilities of designing self-learning information retrieval systems. Another important question is to elaborate such an organization of document search pattern set as to obtain an acceptable response time of the information system to a given information request.A self-learning process of the proposed information system consists in the determination—on a set of document and information request search patterns—of the similarity relation according to L. A. Zadeh.The organization of a set of document search patterns proposed in the paper ensures the limitation of document search pattern set searching process—when retrieving a response to a given information request—to one (or several) subset from previously determined subsets. This makes the information system response time acceptable. The proposed information retrieval strategy is discussed in terms of fuzzy sets.     

浅谈主客体及其相互关系

主体和客体是一对哲学范畴。在人类社会发展的历史进程中,充满着主客体的矛盾和相互作用。主客体之间具有对立统一的实践关系、交互作用的价值关系和双向建构的发展关系。主客体的协调统一是推动社会进步、构建和谐社会的根本动因。     

Optimum coherent imaging of a limited field of view in the presence of angular and aperture noise

An optimal procedure is established for the reconstruction of the angular object distribution in a given field of view (FOV). The object is coherently illuminated and located in the far zone of the receiving aperture. The procedure is “uniformly” optimal in the sense of minimizing the statistical r.m.s. difference between the object distribution, modeled as a random function of the angular coordinates and its reconstructed image, for each direction belonging to the FOV. The observable complex amplitude distribution of the field on the aperture is due in the general case not only to the incidentfield scattered by the object but also to background disturbance, or “angular noise”, randomly distributed inside and outside the FOV, and is affected by “measurement noise”, that is random errors introduced in measuring the aperture field. The reconstruction algorithm consists of summing a truncated series of special functions—prolate spheroidal for the linear case and their generalizations for two dimensional apertures—weighted by appropriate coefficients. These coefficients depend upon the observed aperture field and upon the relative power densities associated with the object field and the various types of noise. The series is truncated to a number of terms (“effective degrees of freedom” of the image) determined through an information theoretical method: each term of the series, suitably ordered, provides an information gain less than the preceding one, and the information gain goes rapidly to zero. A relationship between information transfer and mean squared error for each term in the image series is established. Numerical examples are discussed.     

军备情报说明文的武器对象判定

军备情报说明文往往都是围绕一个或几个武器对象来组织文章内容的,成功获取这些武器对象是对这些文章进行信息抽取的前提,更是以后进行信息整合的基础。军备情报说明文的武器对象判定系统模拟人们在日常阅读中的智力活动,通过标题分析、介引句分析和统计判定,实现了武器对象判定。对此进行了论述。     

吹扫捕集-气相色谱-质谱法测定地表水中苯和甲苯

建立了吹扫捕集-气相色谱-质谱检测地表水中苯和甲苯残留量的方法,选择离子扫描模式检测,在10μg/L～100μg/L范围内呈现良好的线性关系,相关系数大于0.9997,在10、20μg/L添加水平下,苯和甲苯的加标回收率在98.3%～101.2%之间,方法的检出限为5.0μg/L,该方法灵敏度高,分离效果良好,能有效地消除复杂基质带来的干扰,可以作为地表水中苯和甲苯残留量的检测和确证方法。     

A Cross-National Study of Computer News Sites: Global News,Local Sites

The Internet is not only an object of and a tool for study; it is also both simultaneously global and local. In order to address how global and how local it is, this study compares the news content of 1 week from four different computer news web sites in four different countries (using four different languages). These sites use the same code base and all strive to be the same in terms of computer culture. They are global in their reach and in the news they cover, yet they are all local in terms of language and geography. They are ideal locales to study how forces of the global and the local play out on the highly connected Internet, using Google language tools for translation. Findings were surprising in that they showed very little in terms of a pattern of any sort. This is similar to a 1953 UNESCO study of newspapers, but strange in that given the passing of 50 years and the connectedness of the Internet, greater overlap was expected. Link destinations for stories that were on more than one site were also examined, and the Japanese site had more in common with the American site while the two European sites were more alike in this lens. This is also surprising, given that an East/West split was expected. Little work in this specific area was found, and this study highlights some of the questions and methodological difficulties that need to be addressed.     

A Cross-National Study of Computer News Sites: Global News, Local Sites

The Internet is not only an object of and a tool for study; it is also both simultaneously global and local. In order to address how global and how local it is, this study compares the news content of 1 week from four different computer news web sites in four different countries (using four different languages). These sites use the same code base and all strive to be the same in terms of computer culture. They are global in their reach and in the news they cover, yet they are all local in terms of language and geography. They are ideal locales to study how forces of the global and the local play out on the highly connected Internet, using Google language tools for translation. Findings were surprising in that they showed very little in terms of a pattern of any sort. This is similar to a 1953 UNESCO study of newspapers, but strange in that given the passing of 50 years and the connectedness of the Internet, greater overlap was expected. Link destinations for stories that were on more than one site were also examined, and the Japanese site had more in common with the American site while the two European sites were more alike in this lens. This is also surprising, given that an East/West split was expected. Little work in this specific area was found, and this study highlights some of the questions and methodological difficulties that need to be addressed.     

Understanding the majority opinion formation process in online environments: An exploratory approach to Facebook

Majority opinions are often observed in the process of social interaction in online communities, but few studies have addressed this issue with empirical data. To identify an appropriate theoretical lens for explaining majority opinions in online environments, this study investigates the skewness statistic, which indicates how many “Likes” are skewed to major comments on a Facebook post; 3489 posts are gathered from the New York Times Facebook page for 100 days. Results show that time is not an influential factor for skewness increase, but the number of comments has a logarithmic relation to skewness increase. Regression models and Chow tests show that this relationship differs depending on topic contents, but majority opinions are significant in overall. These results suggest that the bandwagon effect due to social affordance can be a suitable mechanism for explaining majority opinion formation in an online environment and that majority opinions in online communities can be misperceived due to overestimation.     

一个求多项式零点的并行迭代及其收敛的初始条件

首先构造了一个求多项式零点的并行迭代,然后对它的收敛性进行了分析,得出其收敛的两种类型的初始条件     

分阶段多航空公司竞争下航班频率研究

航班频率是航空公司航班计划的核心内容,也是飞机指派及机组排班等运行计划的基础。本文首先以航班频率、平均票价、机型指数为参数,建立目标航空公司市场份额模型;然后由目标航空公司的运力供给,以利润最大化为目标,建立航班频率的混合整数规划模型,并利用ILOG软件求解。最后通过实例说明了这种方法在航班频率研究中的应用。     

A Zipfian model of an automatic bibliographic system: an application to MEDLINE.

A Zipfian model of an automatic bibliographic system is developed using parameters describing the contents of it database and its inverted file. The underlying structure of the Zipf distribution is derived, with particular emphasis on its application to work frequencies, especially with regard to the inverted flies of an automatic bibliographic system. Andrew Booth developed a form of Zipf's law which estimates the number of words of a particular frequency for a given author and text. His formulation has been adopted as the basis of a model of term dispersion in an inverted file system. The model is also distinctive in its consideration of the proliferation of spelling errors in free text, and the inclusion of all searchable elements from the system's inverted file. This model is applied to the National Library of Medicine's MEDLINE. The model carries implications for the determination of database storage requirements, search response time, and search exhaustiveness.     

Building beauty: physiognomy on the gas-lit stage

From 1816 onwards, London theatres began to install gas-lighting systems to replace candles. In addition to allowing theatre managers to adjust the level of illumination, gas lights offered greater brightness and visibility for the audience. Actors had to adjust to this new level of exposure that threatened their ability to "look the part." Until this illuminating moment, there had been little need for makeup and actors to adhere to the principles of physiognomy--a system that correlated character traits to facial features. Under the new harsh glare of the gas lights, both the faces of the actors and the theatres themselves were found wanting.     

基于MRAC的矿山电动轮加油系统研究

以矿山电动轮汽车润滑油加油系统为研究对象,本文提出了一种基于Liapunov稳定性理论的模型参考自适应控制(MRAC)方法。分析了该加油系统的结构特点,建立对应数学仿真模型,再利用超稳定理论推导出加油系统自适应控制律,利用Matlab/Simulink对该数学模型进行仿真。模型仿真结果说明,该系统具有较高的稳态精度和较强的鲁棒性。     

Probabilistic latent variable models for unsupervised many-to-many object matching

Object matching is an important task for finding the correspondence between objects in different domains, such as documents in different languages and users in different databases. In this paper, we propose probabilistic latent variable models that offer many-to-many matching without correspondence information or similarity measures between different domains. The proposed model assumes that there is an infinite number of latent vectors that are shared by all domains, and that each object is generated from one of the latent vectors and a domain-specific projection. By inferring the latent vector used for generating each object, objects in different domains are clustered according to the vectors that they share. Thus, we can realize matching between groups of objects in different domains in an unsupervised manner. We give learning procedures of the proposed model based on a stochastic EM algorithm. We also derive learning procedures in a semi-supervised setting, where correspondence information for some objects are given. The effectiveness of the proposed models is demonstrated by experiments on synthetic and real data sets.     

On generic forms of complementary graphs

Each graph may be associated with a certain function called its generic form. If one knows the generic forms of given graphs, then one can easily determine the number of spanning trees in graphs obtained from a complete multi-graph either (1) by adding, or (2) by deleting the edges of disjoint copies of the given graphs. Our obejective here is to give a proof of a simple and useful relation between the generic forms of graphs that are complementary with respect to a complete multi-graph.     

A comparative study of lens protein glycation in various forms of cataract

The aim of this study was to estimate and compare the levels of glycated protein in the lens extracted from patients with cataract of various etiologies. A total of 72 cataract lens were collected. The levels of total proteins, glucose and glycated protein in the lens were studied. Plasma protein and fasting glucose levels were also estimated. The amount of glycation of lens was significantly higher in case of hypermature senile cataract (p<0.01) when compared with other types of cataracts. The levels of lens glucose between the various types of cataracts did not differ significantly. These results indicate that the level of lens glucose alone is not the only determining factor of lens protein glycation.