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131.
针对Hadoop和Spark等大数据分析系统中无先验知识任务的高效执行问题,设计了基于累计工作量(CRW)的任务调度器CRWScheduler。该调度器根据CRW将任务在低权重队列与高权重队列间切换;在为作业分配资源时,同时考虑到作业所在的队列和其瞬时占用资源量,无需作业先验知识即显著提升系统性能。基于Apache Hadoop YARN实现了CRWScheduler原型,在28个节点的基准测试集群上的实验表明,与YARN的公平调度机制相比,作业流时间(JFT)平均降低21%,其中95百分位的作业流时间(JFT)最多降低了35%,并且在与任务级调度程序协作时可获得进一步的性能提升。 相似文献
132.
In an ever-changing environment, Software as a Service (SaaS) can rarely protect users’ privacy. Being able to manage and control the privacy is therefore an important goal for SaaS. Once the participant of composite service is substituted, it is unclear whether the composite service satisfy user privacy requirement or not. In this paper, we propose a privacy policies automatic update method to enhance user privacy when a service participant change in the composite service. Firstly, we model the privacy policies and service variation rules. Secondly, according to the service variation rules, the privacy policies are automatically generated through the negotiation between user and service composer. Thirdly, we prove the feasibility and applicability of our method with the experiments. When the service quantity is 50, ratio that the services variations are successfully checked by monitor is 81%. Moreover, ratio that the privacy policies are correctly updated is 93.6%. 相似文献
133.
《Ceramics International》2022,48(6):7759-7765
Two amorphous BCN–SiC composites, sample BSC (BN + SiC + C) and sample BCSA (B2O3+C + Si + AlN) were prepared from different raw materials via spark plasma sintering (SPS) for 5 min at 1670 °C under a pressure of 30 MPa. Sample BCSA was found to generally outperform sample BSC, and its relative density (99.13% vs. 97.28%), flexural strength (453.1 MPa vs. 334.5 MPa), Vickers’ hardness (19.15 GPa vs. 16.53 GPa), and fracture toughness (5.21 MPa m1/2 vs. 3.76 MPa m1/2). The solid-phase reactions in the binary (sample BSC) and quaternary (sample BCSA) systems were elucidated from X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and thermodynamic calculations. The microstructure of the composites, which were synthesized from two different materials, was also characterized. The grain size and aspect ratio of the lamellar amorphous BCN grains played an important role in improving the mechanical properties of the composites. High-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) were used to clarify the microstructure of the amorphous phase of BCN and its interfacial area. Based on these results, element diffusion was discussed. The mechanism for the microstructural evolution and phase transformation of the composite were also discussed. 相似文献
134.
This paper presents a new on-machine measuring system based on scanning tunneling microscope principle, in order to meet the demand for precision form control of fabricated micro-structures. It is compactly established and mounted on a diamond turning machine, capable of on-machine measuring microstructures with steep slopes and size of tens of micrometers, which remains a challenge task to accomplish undistorted measurement even for general off-line metrological methods. Fly cutting with V-tip fly-cutter was first applied in two directions with interval angle of 60° to form the crossed micro V-grooves, and then efficient on-machine measurement was carried out to characterize the machined surface form without ending the proceeding of the subsequent fabrication. By depth compensation of fly cutting in 120° direction through feedback of on-machine measured results, the surface of rectangular pyramid array with diamond-shaped feature was successfully generated. Experimental results demonstrate that the proposed measuring system is of significance in the fabrication process, owing to its efficient on-machine characterization capability for generating accurate micro-structured surfaces. 相似文献
135.
In recent years, Industry 4.0 makes a significant impact on the manufacturing industry, which enables the business more intelligent and efficient, all while minimizing costs. As known, the logistics concerns in the supply chain always play an important role to a manufacturing company, and decision on the selection of logistics service provider is a key point, especially for healthcare manufacture whose products are the medical devices or equipment of fragility and high cost. Practically there are so many logistics service providers with varieties in service quality, effectiveness, punctuality and reliability, that the manufacturers often encounter the challenge on the provider selection, and healthcare industry is no exception. However, the research on provider selection for healthcare manufacturers is quite limited. In order to help them to make the decision, this paper designs a logistics service provider selection scheme based on a novel weighted density-based hierarchical cluster analysis with integration of the analytic hierarchy process (AHP) for healthcare industry. Initially an evaluation index system reflecting the capability of the candidate providers in all aspects is established. To improve the clustering within the scheme, the density concept and the obtained weights are introduced into the traditional hierarchical cluster analysis (HCA) to shape a novel Weighted Density-Based HCA (WDBHCA). To validate the feasibility of the scheme, a case study on a specified healthcare industry manufacturer is carried out, and results fulfill the case company’s requirement which shows the feasibility of the proposed provider selection scheme. In addition, this scheme can be applied to the provider selection in other fields, as well. 相似文献
136.
温福铁路处于东南沿海地区,台湾海峡西岸,许多桥梁位于海水和地下水侵蚀环境,为了确保设计使用年限达到100年以上,针对东南沿海环境温福线铁路桥梁混凝土抗腐蚀,提高耐久性,应用了CX-SUN抗侵蚀外加剂。CX-SUN海工高性能混凝土抗侵蚀外加剂产品,可解决钢筋混凝土因长期遭受地表海水和地下水中各种化学物质的侵蚀破坏而过早丧失服役现象,使混凝土使用年限提高20~30年。 相似文献
137.
138.
《Journal of Visual Communication and Image Representation》2008,19(4):270-282
The use of sparse representations in signal and image processing is gradually increasing in the past several years. Obtaining an overcomplete dictionary from a set of signals allows us to represent them as a sparse linear combination of dictionary atoms. Pursuit algorithms are then used for signal decomposition. A recent work introduced the K-SVD algorithm, which is a novel method for training overcomplete dictionaries that lead to sparse signal representation. In this work we propose a new method for compressing facial images, based on the K-SVD algorithm. We train K-SVD dictionaries for predefined image patches, and compress each new image according to these dictionaries. The encoding is based on sparse coding of each image patch using the relevant trained dictionary, and the decoding is a simple reconstruction of the patches by linear combination of atoms. An essential pre-process stage for this method is an image alignment procedure, where several facial features are detected and geometrically warped into a canonical spatial location. We present this new method, analyze its results and compare it to several competing compression techniques. 相似文献
139.
140.