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991.
从泛系理论的视角,运用泛系快深频方法对管理科学各理论学派进行审视,对相关理论进行详细解读,将管理科学与方法看成某种特化的泛系方法与泛系管理哲学,在泛系理法基础上实现某种三大显生(系统,关系,泛对称//泛系真善美禅极值原理)及技术化具体建构的分类对策巧显生. 相似文献
992.
介绍了一种新颖的从单张树木图片中提取树木的L-system规则的算法,并将其应用于三维树木建模。用户首先在图片上勾画出树木的主要可见枝干和树冠轮廓,通过图像处理的方法识别出树木的可见枝干的二维骨架;然后依据树木枝干的分布规律对骨架进行三维重建,并抽取其L-system生长规则和几何参数。所得L-system规则在树冠轮廓的约束下,经过迭代生长可以重建树木的分支结构。实验证明,相比以往的规则提取方法,该方法在保持模型质量的前提下,成本更低,方法更加简便。 相似文献
993.
Light detecting and ranging(LiDAR)technology has become an efective way to generate highresolution digital terrain models(DTMs).To generate DTMs,point measurements from non-ground features,such as buildings,vegetation and vehicles,have to be identifed and removed while preserving the terrain points.This paper proposes an efcient mathematical morphology-based multi-level flter to generate DTMs from airborne LiDAR data.Preliminary non-ground points are frst identifed with the characteristics of the multiecho airborne LiDAR data.The localized mathematical morphology opening operations are then immediately applied to the remaining points.By gradually increasing the window size of the flter and using a dynamic critical gradient threshold,the non-ground points are removed,while the ground points are preserved.Eight samples were chosen from eight sites provided with the ISPRS Commission III,Working Group 3,to evaluate the accuracy of our algorithm.Both the qualitative and quantitative experiment analyses show that our morphologybased multi-level flter method achieves promising results,not only in flat urban areas but also in rural areas,especially in preserving complex terrain details,while non-ground spatial objects are removed. 相似文献
994.
We present a skeleton-based algorithm for intrinsic symmetry detection on imperfect 3D point cloud data. The data imperfections such as noise and incompleteness make it difficult to reliably compute geodesic distances, which play essential roles in existing intrinsic symmetry detection algorithms. In this paper, we leverage recent advances in curve skeleton extraction from point clouds for symmetry detection. Our method exploits the properties of curve skeletons, such as homotopy to the input shape, approximate isometry-invariance, and skeleton-to-surface mapping, for the detection task. Starting from a curve skeleton extracted from an input point cloud, we first compute symmetry electors, each of which is composed of a set of skeleton node pairs pruned with a cascade of symmetry filters. The electors are used to vote for symmetric node pairs indicating the symmetry map on the skeleton. A symmetry correspondence matrix (SCM) is constructed for the input point cloud through transferring the symmetry map from skeleton to point cloud. The final symmetry regions on the point cloud are detected via spectral analysis over the SCM. Experiments on raw point clouds, captured by a 3D scanner or the Microsoft Kinect, demonstrate the robustness of our algorithm. We also apply our method to repair incomplete scans based on the detected intrinsic symmetries. 相似文献
995.
An appropriate assessment of end-to-end network performance presumes highly efficient time tracking and measurement with precise time control of the stopping and resuming of program operation. In this paper, a novel approach to solving the problems of highly efficient and precise time measurements on PC-platforms and on ARM-architectures is proposed. A new unified High Performance Timer and a corresponding software library offer a unified interface to the known time counters and automatically identify the fastest and most reliable time source, available in the user space of a computing system. The research is focused on developing an approach of unified time acquisition from the PC hardware and accordingly substituting the common way of getting the time value through Linux system calls. The presented approach provides a much faster means of obtaining the time values with a nanosecond precision than by using conventional means. Moreover, it is capable of handling the sequential time value, precise sleep functions and process resuming. This ability means the reduction of wasting computer resources during the execution of a sleeping process from 100% (busy-wait) to 1-1.5%, whereas the benefits of very accurate process resuming times on long waits are maintained. 相似文献
996.
In this paper we consider the problem of scheduling parallel batching machines with jobs of arbitrary sizes. The machines have identical capacity of size and processing velocity. The jobs are processed in batches given that the total size of jobs in a batch cannot exceed the machine capacity. Once a batch starts processing, no interruption is allowed until all the jobs are completed. First we present a mixed integer programming model of the problem. We show the computational complexity of the problem and optimality properties. Then we propose a novel ant colony optimization method where the Metropolis Criterion is used to select the paths of ants to overcome the immature convergence. Finally, we generate different scales of instances to test the performance. The computational results show the effectiveness of the algorithm, especially for large-scale instances. 相似文献
997.
We present a method for the shape and topology optimization of truss-like structure. First, an initial design of a truss-like structure is constructed by a mesh generator of the finite element method because a truss-like structure can be described by a finite element mesh. Then, the shape and topology of the initial structure is optimized. In order to ensure a truss-like structure can be easily manufactured via intended techniques, we assume the beams have the same size of cross-section, and a method based on the concept of the SIMP method is used for the topology optimization. In addition, in order to prevent intersection of beams and zero-length beams, a geometric constraint based on the signed area of triangle is introduced to the shape optimization. The optimization method is verified by several 2D examples. Influence on compliance of the representative length of beams is investigated. 相似文献
998.
999.
根据目前云计算面临的安全问题,对基于数字证书的云计算安全认证平台进行了研究。首先介绍了云计算的安全现状,分析了随着《电子签名法》的颁布实施,我国数字证书的应用情况,针对云计算存在的四个方面安全问题,结合数字证书的实际应用场景,设计了一种基于数字证书的云计算安全认证解决方案,并对客户利用数字证书与云服务平台加密通信的过程进行了分析,为基于数字证书的云计算安全认证平台建设提供了借鉴和参考。 相似文献
1000.
针对目前公路施工领域力学试验过程中数据可靠性低、不便于监测的缺点,设计了压力试验机网络监测系统;在论述了系统的总体结构的基础上,完成了试验数据采集与网络传输系统的软硬件设计、样品条形码信息管理系统设计,以及试验数据与信息查询系统设计;基于文章方法设计的网络监测系统已经在云南某高速公路工地试验室得到应用,实际运行情况表明,系统工作高效稳定,实现了对工地试验室试验过程的远程监督和管理,以及对样品的过程跟踪,可以有效保证工程项目的施工质量。 相似文献