排序方式: 共有26条查询结果,搜索用时 15 毫秒
21.
In this paper, we introduce a new fuzzy c-means (FCM) method in order to improve the magnetic resonance images’ (MRIs) segmentation. The proposed method combines the FCM and possiblistic c-means (PCM) functions using a weighted Gaussian function. The weighted Gaussian function is given to indicate the spatial influence of the neighbouring pixels on the central pixel. The parameters of weighting coefficients are automatically determined in the implementation using the Gaussian function for every pixel in the image. The proposed method is realised by modifying the objective function of the PCM algorithm to produce memberships and possibilities simultaneously, along with the usual point prototypes or cluster centres for each cluster. The membership values can be interpreted as degrees of possibility of the points belonging to the classes, that is, the compatibilities of the points with the class prototypes to overcome the coincident clusters problem of PCM. The efficiency of the proposed algorithm is demonstrated by extensive segmentation experiments using MRIs and comparison with other state-of-the-art algorithms. In the proposed method, the effect of noise is controlled by incorporating the possibility (typicality) function in addition to the membership function. Consideration of these constraints can greatly control the noise in the image as shown in our experiments. 相似文献
22.
Review:Data center network architecture in cloud computing:review,taxonomy, and open research issues
Han QI Muhammad SHIRAZ Jie-yao LIU Abdullah GANI Zulkanain ABDUL RAHMAN Torki A.ALTAMEEM 《浙江大学学报:C卷英文版》2014,(9)
The data center network(DCN), which is an important component of data centers, consists of a large number of hosted servers and switches connected with high speed communication links. A DCN enables the deployment of resources centralization and on-demand access of the information and services of data centers to users. In recent years, the scale of the DCN has constantly increased with the widespread use of cloud-based services and the unprecedented amount of data delivery in/between data centers, whereas the traditional DCN architecture lacks aggregate bandwidth, scalability, and cost effectiveness for coping with the increasing demands of tenants in accessing the services of cloud data centers. Therefore, the design of a novel DCN architecture with the features of scalability, low cost, robustness, and energy conservation is required. This paper reviews the recent research findings and technologies of DCN architectures to identify the issues in the existing DCN architectures for cloud computing. We develop a taxonomy for the classification of the current DCN architectures, and also qualitatively analyze the traditional and contemporary DCN architectures. Moreover, the DCN architectures are compared on the basis of the significant characteristics, such as bandwidth, fault tolerance, scalability, overhead, and deployment cost. Finally, we put forward open research issues in the deployment of scalable, low-cost, robust, and energy-efficient DCN architecture, for data centers in computational clouds. 相似文献
23.
The usability of IDDQ testing is limited by the subthreshold currents of the low-VT, submicron MOS transistors in the low bias voltage circuits. The paper addresses the cooling of the chip in order to overcome this problem. Experimental results concerning the effect of cooling on the threshold voltage and subthreshold current are presented in the range of –75...25 Centigrade. The subthreshold currents decrease by a factor of about 100–1000 by cooling-down the chip to –75 Centigrade. 相似文献
24.
Boussaa S. Anas Benfadel K. Khodja A. Trad Ayachi M. Boulil R. Bekhedda K. Talbi L. Boukezzata A. Ouadah Y. Allam D. Maifi L. Keffous A. Chetoui A. Torki C. Boudeffar F. Achacha S. Manseri A. Boutarek N. Zaourar Kaci S. 《SILICON》2023,15(3):1145-1157
Silicon - Semiconductors as photoelectric catalysis is recognized as a promising strategy for simultaneous face energy crisis and environmental pollution. In this study, amorphous silicon carbide... 相似文献
25.
Grid computing is a newly developed technology for complex systems with large-scale resource sharing, wide-area communication,
and multi-institutional collaboration. Grid scheduling is an important infrastructure in the grid computing environment. Most
of the existing grids scheduling methods focus on maximizing processor utilization without taking grid load into consideration.
This may lead to significant inefficiencies in performance such as large job queues and processing delays. In this paper,
we propose a multiagent-based scheduling system for computational grids with a new approach. Agent technology is suitable
for a computational grid because of the dynamic, heterogeneous, and autonomous nature of the grid. The main idea of the proposed
system is a combination of a static scheduling using a fixed scheduling algorithm and a dynamic adjustment through the autonomous
behavior of agents. The superiority of the proposed system, in reducing the load of the grid and minimizing the response time
for executing user applications, is demonstrated by simulation experiments. 相似文献
26.
Mohammad Sheikh Hassani Ali Torki Gholamreza Asadollahfardi Seyed F. Saghravani Jalil Shafaei 《Structural Concrete》2021,22(Z1):E756-E768
The effect of using water containing micro‐nano bubbles (WMNB) without adding any admixtures and normal water (NW) on the mechanical properties of cement mortar and concrete samples were investigated. Four various water to cement ratios equal to 0.6, 0.5, 0.4, and 0.35 (ranging from conventional concrete to high strength concrete), and three different curing ages of 7, 28, and 90 days were considered. The experimental results showed that the initial and final setting time of cement paste, the flow of hydraulic cement mortar and the slump of concrete samples made with WMNB were lower than that of made with NW. However, the compressive strength of cement mortar in using WMNB indicated an increase up to 16 and 7% in at 7 and 28 days, respectively. We also concluded that the optimum percentage of water to cement ratio was 0.35, which in that ratio the compressive strength enhancement of concrete made of WMNB reached the peak of 6, 18.3, and 16.3% at 7, 28, and 90 days age, respectively. Whereas increasing water to cement ratio, resulted in reducing the compressive strength of concrete. Besides, the high‐resolution scanning electron microscopy images with Energy Dispersive X‐Ray analysis were briefly conducted to explore the morphological change. 相似文献