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排序方式: 共有989条查询结果,搜索用时 46 毫秒
41.
S.A.A. Akbari Mousavi Sh. Ranjbar Bahadori 《Materials Science and Engineering: A》2011,528(3):1242-1246
X-ray diffraction peak broadening analysis showed that performing a proper heat treatment between the twist extrusion passes of commercially pure copper decreased the coherent domain size and increased the microstrain. Moreover, SEM micrographs illustrated that annealed material contained new formed grains that could not grow due to lack of sufficient time. Under such circumstances, the ultimate strength was elevated about 45 MPa. The deformed material showed texture of simple shear deformation, changing by applying the post annealing. 相似文献
42.
Amr Ahmed Andrew Arnold Luis Pedro Coelho Joshua Kangas Abdul-Saboor Sheikh Eric Xing William Cohen Robert F. Murphy 《Journal of Web Semantics》2010,8(2-3):151-154
The SLIF project combines text-mining and image processing to extract structured information from biomedical literature.SLIF extracts images and their captions from published papers. The captions are automatically parsed for relevant biological entities (protein and cell type names), while the images are classified according to their type (e.g., micrograph or gel). Fluorescence microscopy images are further processed and classified according to the depicted subcellular localization.The results of this process can be queried online using either a user-friendly web-interface or an XML-based web-service. As an alternative to the targeted query paradigm, SLIF also supports browsing the collection based on latent topic models which are derived from both the annotated text and the image data.The SLIF web application, as well as labeled datasets used for training system components, is publicly available at http://slif.cbi.cmu.edu. 相似文献
43.
44.
Optical glass scratching can induce various types of cracks, among which median cracks are extremely detrimental and penetrate deeply under the surface. Due to deep-scratching process complexity, it is challenging to devise a method to predict median crack depth. Indentation testing has been examined comprehensively in prior research works. It has been found that using the correlation between scratch and indentation testing can simplify predictive method development. In this research, a numerical method based on indentation testing is proposed to determine median crack depth during deep scratching. In the first step, an FE model is configured to simulate the indentation testing process and the Cohesive Zone Method is applied to describe median crack behavior. The cohesive parameters calibrated through experimental indentation testing are implemented in the FE scratch model, and the results are compared with the experimental scratch test results. According to the results, the FE scratch model was enhanced by mode II fracture energy and the modeled friction coefficient. The indentation and scratch experiments were conducted with BK7, F2, Fused silica, K5, Pyrex, Quartz, SF6, and SF19. The experimental results prove that the nonlinearity of the median crack depth curve correlates with KIc. A comparison of the experimental and numerical results demonstrates the model is virtually functional for materials with KIc below 1000?kPa?m1/2. Comparisons between the current findings and other studies infer the model and experimental results are accurate and reliable. 相似文献
45.
Matching Trajectories of Anatomical Landmarks Under Viewpoint,Anthropometric and Temporal Transforms
Alexei Gritai Yaser Sheikh Cen Rao Mubarak Shah 《International Journal of Computer Vision》2009,84(3):325-343
An approach is presented to match imaged trajectories of anatomical landmarks (e.g. hands, shoulders and feet) using semantic
correspondences between human bodies. These correspondences are used to provide geometric constraints for matching actions
observed from different viewpoints and performed at different rates by actors of differing anthropometric proportions. The
fact that the human body has approximate anthropometric proportion allows innovative use of the machinery of epipolar geometry
to provide constraints for analyzing actions performed by people of different sizes, while ensuring that changes in viewpoint
do not affect matching. In addition, for linear time warps, a novel measure, constructed only from image measurements of the
locations of anatomical landmarks across time, is proposed to ensure that similar actions performed at different rates are
accurately matched as well. An additional feature of this new measure is that two actions from cameras moving at constant
(and possibly different) velocities can also be matched. Finally, we describe how dynamic time warping can be used in conjunction
with the proposed measure to match actions in the presence of nonlinear time warps. We demonstrate the versatility of our
algorithm in a number of challenging sequences and applications, and report quantitative evaluation of the matching approach
presented. 相似文献
46.
Quality-aware images. 总被引:4,自引:0,他引:4
Zhou Wang Guixing Wu Hamid Rahim Sheikh Eero P Simoncelli En-Hui Yang Alan Conrad Bovik 《IEEE transactions on image processing》2006,15(6):1680-1689
We propose the concept of quality-aware image, in which certain extracted features of the original (high-quality) image are embedded into the image data as invisible hidden messages. When a distorted version of such an image is received, users can decode the hidden messages and use them to provide an objective measure of the quality of the distorted image. To demonstrate the idea, we build a practical quality-aware image encoding, decoding and quality analysis system, which employs: 1) a novel reduced-reference image quality assessment algorithm based on a statistical model of natural images and 2) a previously developed quantization watermarking-based data hiding technique in the wavelet transform domain. 相似文献
47.
Tagged user analysis (TUA) is a generic approximate method of analyzing random access protocols for finite-user finite-buffer systems. This technique decouples the channel contention behavior from the user queuing behavior and allows the use of classical queuing theory results to be directly applicable to the analysis of finite-user finite-buffer random access methods. In this paper, we extend TUA to analyze finite buffer S-ALOHA operating over flat fading radio channels and derive expressions for system performance indices like throughput, average packet delay, blocking probability and queue length. It is shown that for a moderate number of active users, the simulation and analytical results fit closely 相似文献
48.
Javad Akbari Torkestani 《控制论与系统》2013,44(1):77-93
Job scheduling is one of the key issues in the design of grid environments. The performance of the grid system severely degrades if a method does not exist to efficiently schedule the user jobs. In this article, a fully distributed, learning automata–based job scheduling algorithm is proposed for grid environments. The proposed method is composed of two types of procedures: in the first, a procedure is run at the grid nodes and in the second, the procedure is run at the schedulers. The proposed algorithm synchronizes the performance of the schedulers by the learning automata that select their actions using the pseudo-random number generators with the same seed. In this method, the grid computational capacity that is allocated to each scheduler is proportional to its workload. To show the efficiency of the proposed method, several simulation experiments were conducted under different grid scenarios. The obtained results show that the proposed algorithm outperforms several well-known methods in terms of makespan, flow time, and load balancing. 相似文献
49.
Md. Mominul Islam Sheikh Chul-Hwan Kim Ji-Young Lee Sung-Ho Kim Gyeong-Chul Kim Ji-Young Lee Sung-Woong Shim Jae-Won Kim 《Food and Bioproducts Processing》2013,91(1):60-65
Waste money bills that are no longer legal tender are non-recyclable and are usually destroyed. In this study, we used this cellulose-rich material for bioethanol fermentation for the first time. Glucose production was enhanced by using diluted H2SO4 during pretreatment. Different incubation periods were tested for saccharification and subsequent bioethanol fermentation. The highest yield of glucose (41.90 mg/ml) was shown to increase with 27.20% and 25.90% respectively by increasing the reaction period by 30 min and by increasing the acid concentration by 0.5%. Bioethanol production was enhanced by adding 0.4 mM benzoic acid under anoxic condition. In accordance with three different conditions, the highest amount of bioethanol (22.01 mg/ml) was obtained and bioethanol fermentation was increased by 59.38%, 110.02% and 64.13% respectively with 30 min of reaction periods, 0.5% of acid concentrations and under anoxic condition with benzoic acid. This procedure for the production of bioethanol from a waste material would reduce waste money bill management costs and make a profit from ethanol. 相似文献
50.
F. S. Qureshi A. S. Sheikh Z. Khan M. Ahmad 《Journal of Materials Engineering and Performance》1999,8(3):347-352
In this work, a statistical evaluation of the crack-growth process in high-density polyethylene (HDPE) was carried out. The
specimens were compression molded from virgin, molding-grade HDPE. Edgenotched specimens for replicate fatigue testing were
prepared from compression-molded sheets. Fatigue test results were then analyzed, and it is shown that if the crack-growth
process can be characterized as a random process following a power-law-type behavior, then the time to reach a critical crack
length will be distributed according to an inverted lognormal model. 相似文献