Data Bases

نویسنده

  • Rudolf Albrecht
چکیده

The problem of computer assisted literature search is often misstated as the attempt to nd, in a repository of electronic literature, a paper which, according to title and keywords, contains the desired information. This assumes that the original author was correct and complete in assigning keywords, and that the search criteria are free of preconceived expectations on the context in which the information might be found. Crossing the boundaries of disciplinary subbelds is very diicult in this manner. To avoid these problems it is necessary to categorize and classify the documents in the text data base using the full text. This will identify papers of interest, and of unexpected cross-relevance. We show the results of experiments using unsupervised classiication based on neural networks. In astronomy, several years of major journals are now accessible through the Internet. Within a very short time we will have the current body of astronomical knowledge available for computer processing. Using appropriate tools and networks we can consider the electronically available astronomical literature to be one huge text data base, consisting typically of technical/scientiic articles, written in scientiic English and using well deened terminology. In addition to improved access and timely availability electronic publications have the advantage of being searchable. Organizations like the NASA Astrophysics Data System (ADS; http://adswww.harvard.edu/) specialize in such services, freeing the user from having to read an increasingly enormous amount of material in order to nd the desired information.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

New Bases for Polynomial-Based Spaces

Since it is well-known that the Vandermonde matrix is ill-conditioned, while the interpolation itself is not unstable in function space, this paper surveys the choices of other new bases. These bases are data-dependent and are categorized into discretely l2-orthonormal and continuously L2-orthonormal bases. The first one construct a unitary Gramian matrix in the space l2(X) while the late...

متن کامل

Novel Schiff Bases of Pyrrole: Synthesis, Experimental and Theoretical Characterizations, Fluorescent Properties and Molecular Docking

Some new Schiff-base compounds based on pyrrole were synthesized by the reaction of 2-amino-1-methyl-4,5-diphenyl-1H-pyrrole-3-carbonitrile (1)with aromatic aldehydes (2a-2e) in ethanol/acetic acid at room temperature. The structures of the Schiff bases were characterized by full spectral data. The fluorescence emission intensity of the Schiff bases has bee...

متن کامل

The Study of Corrosion Inhibition of Al-pure in HCl by Some New Organic Schiff Bases Using Chemical and Electrochemical Methods

The inhibiting effects of some newly synthesized Schiff bases on the corrosion of Al-Pure in 1.0 M HCl have been studied by means of the chemical and electrochemical methods. The Schiff bases m-Chloroaniline-N-benzylidene (m-CANB), p-Chloroaniline–N-benzylidene (p-CANB), Benzylamine-N-(p-methoxy benzylidene) (BANPMB) and 2-Phenylethylamine-N-(p-methoxy benzylidene) (2PANPMB) were synthesized fr...

متن کامل

Relationship between perception of power bases sport federations' presidents and employees' effectiveness

The purpose of this study was to investigate the relationship between power bases of sport federations' president (PBSP-other) with employees effectiveness. Population of this study was employees included of experts, federation committee chiefs and vise chiefs federation committee, n=288 that completed (POSP-other) questionnaire and employees Effectiveness. PBSP–other questionnaire (with 15 que...

متن کامل

G-Frames, g-orthonormal bases and g-Riesz bases

G-Frames in Hilbert spaces are a redundant set of operators which yield a representation for each vector in the space. In this paper we investigate the connection between g-frames, g-orthonormal bases and g-Riesz bases. We show that a family of bounded operators is a g-Bessel sequences if and only if the Gram matrix associated to its denes a bounded operator.

متن کامل

A Comparative Study of Prehospital Emergency Services Over the Urban and Road Areas in Hamedan Province

Background: Prehospital emergency care services are one of the vital health services in many countries that provide first and immediate medical care to the patients and injured people at the scene and during transfer to healthcare centers. This study was conducted to investigate and compare the use of prehospital emergency services in urban and road emergency bases of Hamadan University of Medi...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2007