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991.
MVC和.NET相结合的高职课程形成性考核系统开发 总被引:2,自引:0,他引:2
郑广成 《计算机与数字工程》2011,39(1):57-60
结合MVC和.NET中Web开发特点,构建了MVC设计模式在.NET中的应用方案,根据形成性考核要求,划分形成性考核系统功能模块,进行了MVC和.NET相结合的高职形成性考核系统设计,最后对系统关键技术和设计过程进行了分析和描述。 相似文献
992.
A fast algorithm for computing moments of gray images based on NAM and extended shading approach 总被引:1,自引:0,他引:1
Computing moments on images is very important in the fields of image processing and pattern recognition. The non-symmetry
and anti-packing model (NAM) is a general pattern representation model that has been developed to help design some efficient
image representation methods. In this paper, inspired by the idea of computing moments based on the S-Tree coding (STC) representation
and by using the NAM and extended shading (NAMES) approach, we propose a fast algorithm for computing lower order moments
based on the NAMES representation, which takes O(N) time where N is the number of NAM blocks. By taking three idiomatic standard
gray images ‘Lena’, ‘F16’, and ‘Peppers’ in the field of image processing as typical test objects, and by comparing our proposed
algorithm with the conventional algorithm and the popular STC representation algorithm for computing the lower order moments,
the theoretical and experimental results presented in this paper show that the average execution time improvement ratios of
the proposed NAMES approach over the STC approach, and also the conventional approach are 26.63%, and 82.57% respectively
while maintaining the image quality. 相似文献
993.
Intra coding in H.264/AVC can significantly improve the compression efficiency at the cost of high computational complexity due to the use of the rate-distortion optimization technique.To reduce the complexity of intra prediction,we propose a feature-based mode decision algorithm for 4×4 intra prediction.This algorithm is motivated by the fact that a good prediction mode usually has a small residue block,which is the difference between the original block and predicted block.The sum of the absolute transformed coefficients and deviation information of residue block are used to measure the distortion of prediction mode and the smoothness of residue block,respectively.According to the ranking of these two features of all possible modes,and together with the most probable mode,small numbers of candidate modes can be determined.Moreover,the candidate modes are further reduced to only one by using two early termination rules based on the correlation of rank and most probable mode.Simulation results demonstrate that the proposed mode decision method reduces about 60% of total encoding time of intra coding with negligible loss of coding performance. 相似文献
994.
In this paper, optimum positioning of the conical cutter for five-axis flank milling of slender surfaces is addressed from the perspective of approximating the tool envelope surface to the data points on the design surface following the minimum zone criterion recommended by ANSI and ISO standards for tolerance evaluation. Based on the observation that a conical surface can be treated as a canal surface, i.e. envelope surface of one-parameter family of spheres, the swept envelope of a conical cutter is represented as a sphere-swept surface. Then, an approach is presented to efficiently compute the signed distance between a point in space and the swept surface without constructing the swept surface itself. The first order differential increment of the signed point-to-surface distance with respect to the differential deformation of the tool axis trajectory surface is derived. By using the distance function, tool path optimizations for semi-finish and finish millings are formulated as two constrained optimization problems in a unified framework, and a sequential approximation algorithm along with a hierarchical algorithmic structure is developed for the optimization. Numerical examples are given to confirm the validity and efficiency of the proposed approach. Comparing with the existing approaches, the present one improves the machining accuracy greatly. The rationale developed applies to general rotary cutters. 相似文献
995.
996.
本文对当前IPv4&IPv6共存网络中的隧道技术进行分析,提出一套改进型的基于源路由单点探测的骨干网隧道发现方法。该方法根据路径中双栈节点间的跳数变化和PMTU变化情况发现隧道,可以发现骨干网络交叉链路中的多级隧道。这对进一步研究过渡时期的网络拓扑发现技术具有一定的参考价值。 相似文献
997.
吴正 《数字社区&智能家居》2011,(16)
针对轴对称的拉深零件的设计,引入了特征编码文件概念,将零件特征以特征编码的形式表示出来。为了实现过程状态模型的智能输出,运用人工神经网络实现自动推理的功能;通过智能推理系统,除去了经验化设计中的不断摸索和改进,将零件的特征造型输入之后,系统能够自动确定零件的工艺流程,进而实现自动化生产。系统能够帮助开发和设计人员迅速的产生设计实例,使开发人员能够更专注于产品的创新活动,对于提高企业的产品设计和研发能力有着重要的实际意义。 相似文献
998.
本文在阐述数据容灾概念与技术的基础上,简单分析了当前几种关键技术,并针对目前我国数字图书馆的可用性与安全性要求高的特点,提出了应用SAN技术实现数字图书馆容灾系统的设计方案,然后对此方案进行了分析,为其他容灾系统的建设起参考与借鉴作用。 相似文献
999.
在开发VxWorks嵌入式平台时,开发厂商会推出一整套交叉编译工具链来配合自身的嵌入式产品,但是这些由商业公司提供的工具链,都不会附有工具链相关的源代码和制作方法,灵活性不足,并且它们一般都与整套开发系统捆绑销售使用,成本较高.为了更好地理解这种技术和降低成本,使用了国际开源组织GNU开发的工具链作为产品开发的工具,提... 相似文献
1000.
Zheng Z Ahmed N Mueller K 《IEEE transactions on visualization and computer graphics》2011,17(12):1959-1968
The unguided visual exploration of volumetric data can be both a challenging and a time-consuming undertaking. Identifying a set of favorable vantage points at which to start exploratory expeditions can greatly reduce this effort and can also ensure that no important structures are being missed. Recent research efforts have focused on entropy-based viewpoint selection criteria that depend on scalar values describing the structures of interest. In contrast, we propose a viewpoint suggestion pipeline that is based on feature-clustering in high-dimensional space. We use gradient/normal variation as a metric to identify interesting local events and then cluster these via k-means to detect important salient composite features. Next, we compute the maximum possible exposure of these composite feature for different viewpoints and calculate a 2D entropy map parameterized in longitude and latitude to point out promising view orientations. Superimposed onto an interactive track-ball interface, users can then directly use this entropy map to quickly navigate to potentially interesting viewpoints where visibility-based transfer functions can be employed to generate volume renderings that minimize occlusions. To give full exploration freedom to the user, the entropy map is updated on the fly whenever a view has been selected, pointing to new and promising but so far unseen view directions. Alternatively, our system can also use a set-cover optimization algorithm to provide a minimal set of views needed to observe all features. The views so generated could then be saved into a list for further inspection or into a gallery for a summary presentation. 相似文献