实验四 外文数据库信息检索

实验四外文数据库信息检索

【实验目的】

熟悉外文数据库信息检索系统的基本情况，掌握外文数据库信息检索系统的检索方法以及检索结果的处理。

学时安排：2 学时

【实验要求】

1、了解外文数据库的检索界面，熟悉文摘款目的著录格式及含义。

2、学会基本检索和高级检索查找文献的方法及过程。

3、根据课题，准确选用布尔逻辑算符、位置算符、截词符，制定出相应的检索式。

4、熟悉文摘的主要著录格式。

5、熟悉索取原始文献的方法。

【实验内容】

一《Ei数据库》

一、检索课题：（1）有关数字电视方面的文献（快速检索）

（2）清华大学有关数字电视方面的文献（专家检索）访问网址：/controller/servlet/Controller

二、检索步骤：

（一）快速检索

（1）分析研究课题，确定检索词：Digital 、TV 、television 等，根据确定的检索词准确选用布尔算符、位置算符、截词符编写检索式

Digital and (TV or television) ___________。

（2）登录检索界面。进入南昌大学图书馆主页, 点击常用数据库列表下的__“Ei 数据库”，进入数据库检索界面。

（3）在系统默认情况下选择easy search。

（4）在检索框内输入Digital and (TV or television) _

（5）执行检索后，命中符合条件的文献___10298_______篇。较切题的1篇文献摘要如下：

Channel estimation methods of digital television terrestrial broadcasting

Yang, Zhi-Xing(Digital TV R and D Cent., Tsinghua Univ.); Wang, Jun; Pan, Chang-Yong; Yang, Lin Source: Tien Tzu Hsueh Pao/Acta Electronica Sinica, v 30, n 9, September, 2002, p 1298-1301 Language: Chinese

ISSN: 0372-2112 CODEN: TTHPAG

Publisher: Chinese Institute of Electronics

Abstract: The development of the Digital Television Terrestrial Broadcasting (DTTB) and

channel characters of the DTTB are first described, and the channel estimation method for the DMB-T (Terrestrial Digital Multimedia/Television Broadcasting) standard innovated by Digital TV R and D Center of Tsinghua University is then discussed in details. Comparing with other existing international standards of DTTB, we conclude that the channel estimation for DMB-T has advantages of low computational complexity and significant suppression of channel noise. (11 refs.)

Ei controlled terms: Television broadcasting- Digital television- Channel capacity- Estimation- Codes (symbols)- Computational complexity- Algorithms

Uncontrolled terms: Digital television terrestrial broadcasting- Channel estimation- PN codes- Digital multimedia terrestrial broadcasting

Classification Code: 716.4Television Systems and Equipment - 716.1Information Theory and Signal Processing - 723Computer Software, Data Handling and Applications - 921 Mathematics - 721.1Computer Theory, Includes Formal Logic, Automata Theory, Switching Theory, Programming Theory

Database: Compendex

（二）专家检索

（1）根据确定的检索词准确地选用布尔逻辑算符、位置算符、截词符编写检索式：(Digital and (TV or television))AND (Tsinghua UNIV wn AF ) （2）选择检索方式：Expert search。

（3）输入检索式：(Digital and (TV or television))AND (Tsinghua UNIV wn AF )

（4）执行检索后，命中符合条件的文献__4___篇。较切题的1篇文献文摘如下：Channel estimation methods of digital television terrestrial broadcastin g⑴

Yang, Zhi-Xing⑵(Digital TV R and D Cent., Tsinghua Univ.)⑶; Wang, Jun; Pan, Chang-Yong; Yang, Lin ⑷Source: Tien Tzu Hsueh Pao/Acta Electronica Sinica, v 30, n 9, September, 2002, p 1298-1301 ⑸Language: Chinese⑥

ISSN: 0372-2112 ⑺CODEN: TTHPAG ⑻

Publisher: Chinese Institute of Electronics ⑼

Abstract: The development of the Digital Television Terrestrial Broadcasting (DTTB) and channel characters of the DTTB are first described, and the channel estimation method for the DMB-T (Terrestrial Digital Multimedia/Television Broadcasting) standard innovated by Digital TV R and D Center of Tsinghua University is then discussed in details. Comparing with other existing international standards of DTTB, we conclude that the channel estimation for DMB-T has advantages of low computational complexity and significant suppression of channel noise. (11 refs.)⑽