全文获取类型
收费全文 | 105篇 |
免费 | 6篇 |
国内免费 | 10篇 |
专业分类
测绘学 | 19篇 |
大气科学 | 10篇 |
地球物理 | 24篇 |
地质学 | 33篇 |
海洋学 | 16篇 |
综合类 | 4篇 |
自然地理 | 15篇 |
出版年
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 4篇 |
2015年 | 2篇 |
2014年 | 6篇 |
2013年 | 3篇 |
2011年 | 2篇 |
2010年 | 3篇 |
2008年 | 5篇 |
2007年 | 5篇 |
2006年 | 1篇 |
2005年 | 9篇 |
2004年 | 8篇 |
2003年 | 5篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 7篇 |
1999年 | 5篇 |
1997年 | 4篇 |
1996年 | 11篇 |
1995年 | 5篇 |
1994年 | 7篇 |
1993年 | 4篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1985年 | 1篇 |
排序方式: 共有121条查询结果,搜索用时 468 毫秒
61.
Yuwen Yang Jian-Hua Yin Jian-Xin Yuan Jeff N. Schulyer 《Computers and Geotechnics》2003,30(8):707-719
A rule-based expert system has been built for selection of both retaining wall types and groundwater control methods in deep excavations in Wuhan city. For this expert system, a new type of generation rule is developed in which one condition is able to be defined with a “third state” that not only contributes directly to reaching the conclusion in a rule, but also factors into calculating the reliability of the conclusion. The traditional backward chaining technique has been improved to accommodate the change of a rule type and a fuzzy backward chaining method IRO has been established to increase reasoning flexibility. Using IRO as a fundamental element, it is convenient to form a complicated reasoning network in the inference engine. Finally, two knowledge bases are built from more than 100 case histories and other resources, and the new expert system proves to be effective in case studies. 相似文献
62.
以新的预报流程和预报技术路线为指导,使用省台指导预报和数值预报产品等资料,通过专家系统、MOS、完全预报等预报方法,分别建立许昌市区域性暴雨预报诊断模型,在此基础上,使用VB6.0语言编程,建立许昌市区域性暴雨集成预报系统。 相似文献
63.
64.
点状符号设计的推理模型 总被引:1,自引:0,他引:1
本文以地图符号的视觉变量和地图要素的表示等级为依据,详细介绍了地图设计专家系统中点状符号设计的推理模型。 相似文献
65.
Sönke Rehder 《Natural Resources Research》1994,3(2):123-131
This article describes initial experiences with an expert system in the scope of an exploration project in Botswana. A simple and easy-to-use expert system shell for personal computers was applied to construct an inference network for epigenetic gold deposits. The main objective, however, was not the automation of human intelligence but the structural analysis of domain knowledge for a target assessment. Aspects of human reasoning are discussed and compared with machine reasoning. Some actual problems concerning the inversion of rules under uncertainty, contrary evidences, and prior probabilities are discussed. Technical aspects like costs and schedule are included in the exploration model. Three different approaches for constructing an inference network are described. 相似文献
66.
67.
An expert system is presented for automated time series analysis of laboratory sample input signals.Thesystem,AUTOCORR,builds a model of the time series by identifying the processes that are present.These are an uncorrelated random process and,underlying this,possibly one or more of the following:a first-order autoregressive process,a trend and a periodic process.AUTOCORR has a knowledge baseof 44 rules and 41 facts for this purpose.The employed shell,INFER,allows the use of algorithmicprocedures.Elaborate tests with simulated signals show that AUTOCORR has a very low false positivescore and is successful in describing time series for laboratory simulation models. 相似文献
68.
69.
Knowledge-based systems as decision support tools in an ecosystem approach to fisheries: Comparing a fuzzy-logic and a rule-based approach 总被引:1,自引:0,他引:1
Astrid Jarre Barbara Paterson Coleen L. Moloney David C.M. Miller John G. Field Anthony M. Starfield 《Progress in Oceanography》2008,79(2-4):390
In an ecosystem approach to fisheries (EAF), management must draw on information of widely different types, and information addressing various scales. Knowledge-based systems assist in the decision-making process by summarising this information in a logical, transparent and reproducible way. Both rule-based Boolean and fuzzy-logic models have been used successfully as knowledge-based decision support tools. This study compares two such systems relevant to fisheries management in an EAF developed for the southern Benguela. The first is a rule-based system for the prediction of anchovy recruitment and the second is a fuzzy-logic tool to monitor implementation of an EAF in the sardine fishery. We construct a fuzzy-logic counterpart to the rule-based model, and a rule-based counterpart to the fuzzy-logic model, compare their results, and include feedback from potential users of these two decision support tools in our evaluation of the two approaches. With respect to the model objectives, no method clearly outperformed the other. The advantages of numerically processing continuous variables, and interpreting the final output, as in fuzzy-logic models, can be weighed up against the advantages of using a few, qualitative, easy-to-understand categories as in rule-based models. The natural language used in rule-based implementations is easily understood by, and communicated among, users of these systems. Users unfamiliar with fuzzy-set theory must “trust” the logic of the model. Graphical visualization of intermediate and end results is an important advantage of any system. Applying the two approaches in parallel improved our understanding of the model as well as of the underlying problems. Even for complex problems, small knowledge-based systems such as the ones explored here are worth developing and using. Their strengths lie in (i) synthesis of the problem in a logical and transparent framework, (ii) helping scientists to deliberate how to apply their science to transdisciplinary issues that are not purely scientific, and (iii) representing vehicles for delivering state-of-the-art science to those who need to use it. Possible applications of this approach for ecosystems of the Humboldt Current are discussed. 相似文献
70.