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排序方式: 共有2480条查询结果,搜索用时 15 毫秒
41.
Baha Vural kok Mehmet Yilmaz Mustafa Akpolat 《International Journal of Pavement Engineering》2017,18(12):1052-1059
In this study, the rheological and conventional properties of binders prepared with crumb rubber (CR) and FT-paraffin were compared to styrene-butadiene-styrene (SBS)-modified binders’ properties. The objective of this study was to determine which modified binders in different combinations of the CR and the FT-paraffin exhibited better performance than the SBS-modified binders, in terms of conventional and rheological properties. Results showed that the additives exhibited different performances for different types of tests. Many of the combinations including the common usage of the CR and the FT-paraffin performed better at high temperature than the SBS modification. Overall, the test results show that the binders prepared by 6% CR with 3 and 4% FT-paraffin and those prepared with 8% CR with 3% FT-paraffin were better binders than the 4% SBS-modified binder, in terms of low and high temperature properties. 相似文献
42.
Ali Firat Cabalar Waleed Sulaiman Mustafa 《International Journal of Pavement Engineering》2017,18(8):714-726
Materials forming sand grains and colluvial soil deposits have a distinct structure, consisting of a composite matrix of coarse and fine soil grains. The influence of sand grains content on the behaviour of sand–clay mixtures was investigated by a series of intensive laboratory experiments. The California bearing ratio (CBR), unconfined compression strength (UCS) and compaction tests were carried out on various contents of sand and clay mixtures. The sand–clay mixtures were prepared with sand contents of 0, 10, 20, 30, 40, and 50% by weight. The laboratory tests on these mixtures have indicated that their behaviour will depend on the relative concentration of the sand and clay samples. The results of the tests showed a decrease in the UCS, and an increase the CBR values with an increase in the amount of sand. An increase in dry unit weight and a decrease in respective moisture content by an increase in the amount of sand were observed in the compaction tests. 相似文献
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45.
Shahad Alyousif Mohammed Dauwed Rafal Nader Mohammed Hasan Ali Mustafa Musa Jabar Ahmed Alkhayyat 《计算机、材料和连续体(英文)》2023,75(1):531-546
The number of mobile devices accessing wireless networks is skyrocketing due to the rapid advancement of sensors and wireless communication technology. In the upcoming years, it is anticipated that mobile data traffic would rise even more. The development of a new cellular network paradigm is being driven by the Internet of Things, smart homes, and more sophisticated applications with greater data rates and latency requirements. Resources are being used up quickly due to the steady growth of smartphone devices and multimedia apps. Computation offloading to either several distant clouds or close mobile devices has consistently improved the performance of mobile devices. The computation latency can also be decreased by offloading computing duties to edge servers with a specific level of computing power. Device-to-device (D2D) collaboration can assist in processing small-scale activities that are time-sensitive in order to further reduce task delays. The task offloading performance is drastically reduced due to the variation of different performance capabilities of edge nodes. Therefore, this paper addressed this problem and proposed a new method for D2D communication. In this method, the time delay is reduced by enabling the edge nodes to exchange data samples. Simulation results show that the proposed algorithm has better performance than traditional algorithm. 相似文献
46.
Zaher Al Aghbari Ibrahim Kamel Ahmed Mustafa 《Peer-to-Peer Networking and Applications》2011,4(4):391-409
Recently, many applications have used Peer-to-Peer (P2P) systems to overcome the current problems with client/server systems
such as non-scalability, high bandwidth requirement and single point of failure. In this paper, we propose an efficient scheme
to support efficient range query processing over structured P2P systems, while balancing both the storage load and access
load. The paper proposes a rotating token scheme to balance the storage load by placing joining nodes in appropriate locations
in the identifier space to share loads with already overloaded nodes. Then, to support range queries, we utilize an order-preserving
mapping function to map keys to nodes in order preserving way and without hashing. This may result in an access load imbalance
due to non-uniform distribution of keys in the identifier space. Thus, we propose an adaptive replication scheme to relieve
overloaded nodes by shedding some load on other nodes to balance the access load. We derive a formula for estimating the overhead
of the proposed adaptive replication scheme. In this study, we carry simulation experiments with synthetic data to measure
the performance of the proposed schemes. Our simulation experiments show significant gains in both storage load balancing
and access load balancing. 相似文献
47.
In this paper, we present general formulae for the mask of (2b + 4)-point n-ary approximating as well as interpolating subdivision schemes for any integers ${b\,\geqslant\,0}$ and ${n\,\geqslant\,2}$ . These formulae corresponding to the mask not only generalize and unify several well-known schemes but also provide the mask of higher arity schemes. Moreover, the 4-point and 6-point a-ary schemes introduced by Lian [Appl Appl Math Int J 3(1):18–29, 2008] are special cases of our general formulae. 相似文献
48.
Mustafa Sarıdemir 《Expert systems with applications》2011,38(11):14257-14268
Compressive strength and splitting tensile strength are both mechanical properties of concrete that are utilized in structural design. This study presents gene expression programming (GEP) as a new tool for the formulations of splitting tensile strength from compressive strength of concrete. For purpose of building the GEP-based formulations, 536 experimental data have been gathered from existing literature. The GEP-based formulations are developed for splitting tensile strength of concrete as a function of age of specimen and cylinder compressive strength. In experimental parts of this study, cylindrical specimens of 150 × 300 mm and 100 × 200 mm in dimensions are utilized. Training and testing sets of the GEP-based formulations are randomly separated from the complete experimental data. The GEP-based formulations are also validated with additional 173 data of experimental results other than the data used in training and testing sets of the GEP-based formulations. All of the results obtained from the GEP-based formulations are compared with the results obtained from experimental data, the developed regression-based formulation and formulas given by some national building codes. These comparisons showed that the GEP-based formulations appeared to well agree with the experimental data and found to be quite reliable. 相似文献
49.
We present some new results about oscillation and asymptotic behavior of solutions of third order nonlinear differential equations of the form
(r2(t)(r1(t)y′)′)′+p(t)y′+q(t)f(y(g(t)))=0. 相似文献
50.
Abdulnasir Yildiz Mehmet Akın Mustafa Poyraz 《Expert systems with applications》2011,38(10):12880-12890
Obstructive sleep apnea (OSA) is a highly prevalent sleep disorder. The traditional diagnosis methods of the disorder are cumbersome and expensive. The ability to automatically identify OSA from electrocardiogram (ECG) recordings is important for clinical diagnosis and treatment. In this study, we proposed an expert system based on discrete wavelet transform (DWT), fast-Fourier transform (FFT) and least squares support vector machine (LS-SVM) for the automatic recognition of patients with OSA from nocturnal ECG recordings. Thirty ECG recordings collected from normal subjects and subjects with sleep apnea, each of approximately 8 h in duration, were used throughout the study. The proposed OSA recognition system comprises three stages. In the first stage, an algorithm based on DWT was used to analyze ECG recordings for the detection of heart rate variability (HRV) and ECG-derived respiration (EDR) changes. In the second stage, an FFT based power spectral density (PSD) method was used for feature extraction from HRV and EDR changes. Then, a hill-climbing feature selection algorithm was used to identify the best features that improve classification performance. In the third stage, the obtained features were used as input patterns of the LS-SVM classifier. Using the cross-validation method, the accuracy of the developed system was found to be 100% for using a subset of selected combination of HRV and EDR features. The results confirmed that the proposed expert system has potential for recognition of patients with suspected OSA by using ECG recordings. 相似文献