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31.
介绍了一个水工图形库系统(HydraulicGraphicsBaseSystem),阐述了系统的总体设计方案,并对系统中涉及的关键技术进行了讨论. 相似文献
32.
本文简述了用于红外窗口同时起到增透和保护双重作用的DLC薄膜的特性,红外应用,以及应用中需解决的问题。 相似文献
33.
Operator context scanning to support high segmentation rates for real time license plate recognition
Ioannis Giannoukos Author Vitae Christos-Nikolaos Anagnostopoulos Author VitaeAuthor Vitae Eleftherios Kayafas Author Vitae 《Pattern recognition》2010,43(11):3866-3878
Introducing high definition videos and images in object recognition has provided new possibilities in the field of intelligent image processing and pattern recognition. However, due to the large amount of information that needs to be processed, the computational costs are high, making the HD systems slow. To this end, a novel algorithm applied to sliding window analysis, namely Operator Context Scanning (OCS), is proposed and tested on the license plate detection module of a License Plate Recognition (LPR) system. In the LPR system, the OCS algorithm is applied on the Sliding Concentric Windows pixel operator and has been found to improve the LPR system’s performance in terms of speed by rapidly scanning input images focusing only on regions of interest, while at the same time it does not reduce the system effectiveness. Additionally, a novel characteristic is presented, namely, the context of the image based on a sliding windows operator. This characteristic helps to quickly categorize the environmental conditions upon which the input image was taken. The algorithm is tested on a data set that includes images of various resolutions, acquired under a variety of environmental conditions. 相似文献
34.
Bin Li Zheng Zhou Dejian Li Weixia Zou 《Journal of Network and Computer Applications》2011,34(6):1894-1902
Ultra-wideband (UWB) has been widely recommended for significant commercial and military applications. However, the well-derived coherent structures for UWB signal detection are either computationally complex or hardware impractical in the presence of the intensive multipath propagations. In this article, based on the nonparametric Parzen window estimator and the probabilistic neural networks, we suggest a low-complexity and noncoherent UWB detector in the context of distributed wireless sensor networks (WSNs). A novel characteristic spectrum is firstly developed through a sequence of blind signal transforms. Then, from a pattern recognition perspective, four features are extracted from it to fully exploit the inherent property of UWB multipath signals. The established feature space is further mapped into a two-dimensional plane by feature combination in order to simplify algorithm complexity. Consequently, UWB signal detection is formulated to recognize the received patterns in this formed 2-D feature plane. With the excellent capability of fast convergence and parallel implementation, the Parzen Probabilistic Neural Network (PPNN) is introduced to estimate a posteriori probability of the developed patterns. Based on the underlying Bayesian rule of PPNN, the asymptotical optimal decision bound is finally determined in the feature plane. Numerical simulations also validate the advantages of our proposed algorithm. 相似文献
35.
Fabien Tricoire Martin Romauch Karl F. Doerner Richard F. Hartl 《Computers & Operations Research》2010,37(2):351-367
We present the multi-period orienteering problem with multiple time windows (MuPOPTW), a new routing problem combining objective and constraints of the orienteering problem (OP) and team orienteering problem (TOP), constraints from standard vehicle routing problems, and original constraints from a real-world application. The problem itself comes from a real industrial case. Specific route duration constraints result in a route feasibility subproblem. We propose an exact algorithm for this subproblem, and we embed it in a variable neighborhood search method to solve the whole routing problem. We then provide experimental results for this method. We compare them to a commercial solver. We also adapt our method to standard benchmark OP and TOP instances, and provide comparative tables with state-of-the-art algorithms. 相似文献
36.
基于兴趣视图子集的流立方体计算方法 总被引:1,自引:0,他引:1
流立方体计算是流式数据多维分析的重要基础,然而流式数据的动态性、无限性、突发性等特征使其面临巨大的挑战.在实际应用中,用户的兴趣通常集中在部分视图上,基于这个特点提出了一种基于兴趣视图子集的计算方法,依据用户历史查询信息确定兴趣视图子集与兴趣路径,同时定义了Stream-Tree结构用于在主存中物化存储兴趣视图子集所包含的数据单元,在运行过程中依据多层次时间窗口约束不断更新和维护Stream-Tree中存储的数据单元,而对于稀疏数据单元仅保留高层次的聚集值.实验和分析表明,该方法能够在有限的主存空间中维持流立方体当前窗口内的数据单元,同时能够支持快速更新维护存储结构和响应用户查询. 相似文献
37.
We propose a nonlinear mathematical model to consider production scheduling and vehicle routing with time windows for perishable food products in the same framework. The demands at retailers are assumed stochastic and perishable goods will deteriorate once they were produced. Thus the revenue of the supplier is uncertain and depends on the value and the transaction quantity of perishable products when they are carried to retailers. The objective of this model is to maximize the expected total profit of the supplier. The optimal production quantities, the time to start producing and the vehicle routes can be determined in the model simultaneously. Furthermore, we elaborate a solution algorithm composed of the constrained Nelder–Mead method and a heuristic for the vehicle routing with time windows to solve the complex problem. Computational results indicate our algorithm is effective and efficient. 相似文献
38.
In this paper, we consider the manpower allocation problem with time windows, job-teaming constraints and a limited number of teams (m-MAPTWTC). Given a set of teams and a set of tasks, the problem is to assign to each team a sequential order of tasks to maximize the total number of assigned tasks. Both teams and tasks may be restricted by time windows outside which operation is not possible. Some tasks require cooperation between teams, and all teams cooperating must initiate execution simultaneously. We present an integer programming model for the problem, which is decomposed using Dantzig–Wolfe decomposition. The problem is solved by column generation in a branch-and-price framework. Simultaneous execution of tasks is enforced by the branching scheme. To test the efficiency of the proposed algorithm, 12 realistic test instances are introduced. The algorithm is able to find the optimal solution in 11 of the test instances. The main contribution of this article is the addition of synchronization between teams in an exact optimization context. 相似文献
39.
Asynchronous double-precision windows based unmanned aerial vehicle real-time path planning 总被引:1,自引:0,他引:1
REN Min & HUO XiaoHua College of Mechatronic Engineering Automation National University of Defense Technology Changsha China Communication Institute Equipment Academy of Air Force Beijing 《中国科学:信息科学(英文版)》2010,(2):215-222
A real-time path planning approach based on asynchronous double-precision windows is proposed for unmanned aerial vehicles (UAVs). In this proposed method, cursory paths and elaborate paths are planned respectively in the global and local windows. Specifically, global cursory path planner and local elaborate path planner are integrated by rolling two windows on different frequencies with different modes. Simulation results demonstrate that the proposed approach is effective for realizing a balance between t... 相似文献
40.
频繁项集挖掘是数据流挖掘中的一个热点问题.提出了一种新的数据流频繁闭项集挖掘算法MFCI-SW.首先设计了两个新的数据结构:频繁闭项集表FCIL和频繁闭合模式树MFCI-SW-Tree,在此基础上以滑动窗口中的基本窗口为更新单位,在每个基本窗口中提取出频繁闭项集的数据项,将其支持度F和窗口序列号K存到FCIL中;然后随着新基本窗口的到来,通过删除频繁闭项集表中K值最小的数据项和插入新数据项完成对FCIL的更新和MFCI-SW-Tree树的裁剪;最后在MFCI-SW-Tree中可以迅速挖掘出满足用户需要的频繁闭项集.实验结果证明了该算法在执行效率上明显优于DS-CFI算法. 相似文献