首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   364篇
  免费   5篇
  国内免费   2篇
电工技术   2篇
化学工业   64篇
金属工艺   8篇
机械仪表   2篇
建筑科学   10篇
能源动力   5篇
轻工业   30篇
水利工程   3篇
石油天然气   1篇
无线电   32篇
一般工业技术   52篇
冶金工业   47篇
原子能技术   1篇
自动化技术   114篇
  2024年   1篇
  2023年   6篇
  2022年   16篇
  2021年   19篇
  2020年   11篇
  2019年   10篇
  2018年   11篇
  2017年   8篇
  2016年   9篇
  2015年   3篇
  2014年   12篇
  2013年   19篇
  2012年   18篇
  2011年   36篇
  2010年   23篇
  2009年   15篇
  2008年   25篇
  2007年   12篇
  2006年   19篇
  2005年   9篇
  2004年   12篇
  2003年   8篇
  2002年   7篇
  2001年   5篇
  2000年   5篇
  1999年   3篇
  1998年   2篇
  1997年   7篇
  1996年   5篇
  1995年   4篇
  1994年   4篇
  1993年   1篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1988年   1篇
  1987年   2篇
  1986年   1篇
  1984年   2篇
  1982年   6篇
  1981年   2篇
  1980年   2篇
  1979年   1篇
  1977年   4篇
  1969年   2篇
排序方式: 共有371条查询结果,搜索用时 15 毫秒
101.
Responds to the comments of P. L. Ackerman (see record 2006-12925-012), D. Y. Dai (see record 2006-12925-013), and M. C. Gridley (see record 2006-12925-014) on E. S. Spelke's original article "Sex differences in intrinsic aptitude for mathematics and science? A critical review" (see record 2005-15840-001). Here, the current authors first consider Ackerman's criticism of IQ measures of cognitive sex differences, as well as his suggestion that Advanced Placement tests be used as a second measure. Next, the authors discuss Dai's suggestion that cognition and motivation, abilities and strategies, are inseparably bound in any meaningful measure of aptitude for mathematics and science. Finally, the authors address Gridley's suggestion that differences in men's and women's thinking styles and preferences explain gender disparities in math and science fields. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
102.
We address non-preemptive non-clairvoyant online scheduling of parallel jobs on a Grid. We consider a Grid scheduling model with two stages. At the first stage, jobs are allocated to a suitable Grid site, while at the second stage, local scheduling is independently applied to each site. We analyze allocation strategies depending on the type and amount of information they require. We conduct a comprehensive performance evaluation study using simulation and demonstrate that our strategies perform well with respect to several metrics that reflect both user- and system-centric goals. Unfortunately, user run time estimates and information on local schedules does not help to significantly improve the outcome of the allocation strategies. When examining the overall Grid performance based on real data, we determined that an appropriate distribution of job processor requirements over the Grid has a higher performance than an allocation of jobs based on user run time estimates and information on local schedules. In general, our experiments showed that rather simple schedulers with minimal information requirements can provide a good performance.  相似文献   
103.
Physical A* (PHA*) and its multi-agent version MAPHA* are algorithms that find the shortest path between two points in an unknown real physical environment with one or many mobile agents [A. Felner et al. Journal of Artificial Intelligence Research, 21:631–679, 2004; A. Felner et al. Proceedings of the First International Joint Conference on Autonomous Agents and Multi-Agent Systems, Bologna, Italy, 2002:240–247]. Previous work assumed a complete sharing of knowledge between agents. Here we apply this algorithm to a more restricted model of communication which we call large pheromones, where agents communicate by writing and reading data at nodes of the graph that constitutes their environment. Previous works on pheromones usually assumed that only a limited amount of data can be written at each node. The large pheromones model assumes no limitation on the size of the pheromones and thus each agent can write its entire knowledge at a node. We show that with this model of communication the behavior of a multi-agent system is almost as good as with complete knowledge sharing. Under this model we also introduce a new type of agent, a communication agent, that is responsible for spreading the knowledge among other agents by moving around the graph and copying pheromones. Experimental results show that the contribution of communication agents is rather limited as data is already spread to other agents very well with large pheromones  相似文献   
104.
This article outlines a framework for developmentally oriented policy research. Drawing from U. Bronfenbrenner's (1995) dynamic developmental systems theory, the authors suggest ways in which the key tenets of process, persons, context, and time can inform policy research in developmental psychology and can be used to support a causal interpretation of the results of those analyses. Conceptualizing public policies from a dynamic developmental systems perspective has a variety of implications for future research, and this article considers some of these implications. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
105.
106.
Quality enhancements of digital outline fonts   总被引:4,自引:0,他引:4  
Digital fonts are easily available today and their use has become widespread. Nevertheless, the visual quality of printed and displayed text and the technical quality of digital typefaces are often unsatisfactory. The foremost reason for this situation is that font manufacturing systems manipulate font representations through low-level operations. In this paper we examine several aspects of font quality, and present a method for enhancing the quality of a typeface given in today's standard representation, the outline (boundary) representation. The method is based on the usage of high-level typographic features, and includes enhancements to both individual glyphs and complete fonts. Glyph enhancements include elimination of redundant points, insertion of essential points, corrections to contour orientations and inter-penetrations, and vertical and horizontal coherence. Font enhancements include regularization of font weights and sizes, serif unification, and feature extraction and discrimination. Our method is comprised of several algorithms that have been implemented in a commercial font manufacturing system, achieving enhanced quality of the fonts produced.  相似文献   
107.
Geometrical symmetries are commonly exploited to improve the efficiency of search algorithms. A new type of symmetry in permutation state spaces, duality, is introduced. Each state has a dual state. Both states share important attributes such as their distance to the goal. Given a state S, it is shown that an admissible heuristic of the dual state of S is an admissible heuristic for S. This provides opportunities for additional heuristic evaluations. An exact definition of the class of problems where duality exists is provided. A new search algorithm, dual search, is presented which switches between the original state and the dual state when it seems likely that the switch will improve the chance of reaching the goal faster. The decision of when to switch is very important and several policies for doing this are investigated. Experimental results show significant improvements for a number of applications, for using the dual state's heuristic evaluation and/or dual search.  相似文献   
108.
The notion of parts in a shape plays an important role in many geometry problems, including segmentation, correspondence, recognition, editing, and animation. As the fundamental geometric representation of 3D objects in computer graphics is surface-based, solutions of many such problems utilize a surface metric, a distance function defined over pairs of points on the surface, to assist shape analysis and understanding. The main contribution of our work is to bring together these two fundamental concepts: shape parts and surface metric. Specifically, we develop a surface metric that is part-aware. To encode part information at a point on a shape, we model its volumetric context – called the volumetric shape image (VSI) – inside the shape's enclosed volume, to capture relevant visibility information. We then define the part-aware metric by combining an appropriate VSI distance with geodesic distance and normal variation. We show how the volumetric view on part separation addresses certain limitations of the surface view, which relies on concavity measures over a surface as implied by the well-known minima rule. We demonstrate how the new metric can be effectively utilized in various applications including mesh segmentation, shape registration, part-aware sampling and shape retrieval.  相似文献   
109.
Picture-naming performance for 48 black-and-white drawings was investigated in 1,145 Hebrew speakers, ages 5–86. Both a linear and a curvilinear quadratic model fit the data, reflecting an increase in ability with age as well as an increase followed by a decrease beyond that linear rise. Late-life performance was more affected by access difficulty than was early-life performance, with children's responses limited by lexicon size. Immigrants performed more poorly than nonimmigrants, but an identical correlation between participant age and naming scores was found in both groups. We discuss the role of vocabulary funds and controlled access in naming pictures throughout life. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
110.
Smoothing noises while preserving strong edges in images is an important problem in image processing. Image smoothing filters can be either explicit (based on local weighted average) or implicit (based on global optimization). Implicit methods are usually time‐consuming and cannot be applied to joint image filtering tasks, i.e., leveraging the structural information of a guidance image to filter a target image. Previous deep learning based image smoothing filters are all implicit and unavailable for joint filtering. In this paper, we propose to learn explicit guidance feature maps as well as offset maps from the guidance image and smoothing parameter that can be utilized to smooth the input itself or to filter images in other target domains. We design a deep convolutional neural network consisting of a fully‐convolution block for guidance and offset maps extraction together with a stacked spatially varying deformable convolution block for joint image filtering. Our models can approximate several representative image smoothing filters with high accuracy comparable to state‐of‐the‐art methods, and serve as general tools for other joint image filtering tasks, such as color interpolation, depth map upsampling, saliency map upsampling, flash/non‐flash image denoising and RGB/NIR image denoising.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号