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221.
Asymptotically optimal cooperative wireless networks with reduced signaling complexity 总被引:1,自引:0,他引:1
Petros Elia Frederique Oggier P. Vijay Kumar 《Selected Areas in Communications, IEEE Journal on》2007,25(2):258-267
This paper considers an orthogonal amplify-and-forward (OAF) protocol for cooperative relay communication over Rayleigh-fading channels in which the intermediate relays are permitted to linearly transform the received signal and where the source and relays transmit for equal time durations. The diversity-multiplexing gain (D-MG) tradeoff of the equivalent space-time channel associated to this protocol is determined and a cyclic-division-algebra-based D-MG optimal code constructed. The transmission or signaling alphabet of this code is the union of the QAM constellation and a rotated version of QAM. The size of this signaling alphabet is small in comparison with prior D-MG optimal constructions in the literature and is independent of the number of participating nodes in the network 相似文献
222.
223.
Alfredo Rondinella Erika Furlani Michele Magnan Fabio Scagnetto Stefano Driussi Elia Marin Stefano Maschio 《Ceramics International》2021,47(17):24494-24500
Powder mixtures of Alumina and Chromia, blended in different proportions (1, 3, 5 and 10%wt) by attrition milling, were fired either by pressureless sintering in air and hot pressing under vacuum. The resulting materials, characterized by X-ray diffraction, Raman spectroscopy, SEM, hardness and fracture toughness showed that all the compositions form complete solid solution which maintain the same crystal structures of corundum; chromia addition retards materials' densification of pressureless fired samples but not that of hot-pressed samples. Data from Raman spectroscopy and SEM/EDXS showed the appearance of Ti- and Mn-based impurities near the indentation print, in particular on fractured grains. The addition of chromia improves hardness, but does not affect toughness which is, on the other hand, greatly influenced by materials’ residual porosity. 相似文献
224.
fMRI-based hierarchical SVM model for the classification and grading of liver fibrosis 总被引:1,自引:0,他引:1
Sela Y Freiman M Dery E Edrei Y Safadi R Pappo O Joskowicz L Abramovitch R 《IEEE transactions on bio-medical engineering》2011,58(9):2574-2581
We present a novel method for the automatic classification and grading of liver fibrosis based on hepatic hemodynamic changes measured noninvasively from functional MRI (fMRI) scans combined with hypercapnia and hyperoxia. The supervised learning method automatically creates a classification and grading model for liver fibrosis grade from training datasets. It constructs a statistical model of liver fibrosis by evaluating the signal intensity time course and local variance in T2(*)-W fMRI scans acquired during the breathing of air, air-carbon dioxide, and carbogen with a hierarchical multiclass binary-based support vector machine (SVM) classifier. Two experimental studies on 162 slices from 34 mice with the hierarchical multiclass binary-based SVM classifier yield 96.9% separation accuracy between healthy and histological-based fibrosis graded subjects, and an overall accuracy of 75.3% for healthy, fibrotic, and cirrhotic subjects. These results outperform existing image-based methods that can discriminate between healthy and mild-grade fibrosis subjects. 相似文献
225.
Wenz JR Garry FB Lombard JE Elia R Prentice D Dinsmore RP 《Journal of dairy science》2005,88(10):3496-3499
The objective of this study was to evaluate the effect of intramuscular (i.m.) ceftiofur (2.2 mg/kg) on important outcomes of systemically mild clinical mastitis episodes in lactating dairy cattle. Cows with clinical mastitis were randomly assigned to a treatment group: pirlimycin intramammary (i.m.m.) (n = 35), pirlimycin i.m.m. and ceftiofur i.m.m. (n = 36), cephapirin i.m.m. (n = 40), cephapirin i.m. and ceftiofur i.m. (n = 33). Sixty-nine, 22, and 9% of initial cultures were gram-negative, gram-positive, and mixed, respectively. Logistic regression analysis showed no significant associations between treatment groups and loss of quarter, recurrence, or culling. Mixed infections, positive milk culture at 7 d after leaving hospital pen, decreased rumen motility, and absence of udder firmness were associated with increased odds of mastitis recurrence. The results suggest that i.m. ceftiofur treatment has no beneficial effects on the outcome of systemically mild clinical mastitis. 相似文献
226.
BLUB LOUNGE俱乐部是一个美妙的海底世界。灯光、装饰、家具和空间的形态都在刻意营造水下的感觉。在这里就餐可以尽情享受音乐和迪斯科给人们带来的愉悦心情。光线穿过绿植和支架的缝隙,洒落到整个室内,像极了海底不知名的光亮,仿佛都能感受到海底水流的涌动。 相似文献
227.
In situ evaluation of the fruit and oil characteristics of the main Lebanese olive germplasm 下载免费PDF全文