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One specific class of non-linear evolution equations, known as the Tzitzéica-type equations, has received great attention from a group of researchers involved in non-linear science. In this article, new exact solutions of the Tzitzéica-type equations arising in non-linear optics, including the Tzitzéica, Dodd–Bullough–Mikhailov and Tzitzéica–Dodd–Bullough equations, are obtained using the expa function method. The integration technique actually suggests a useful and reliable method to extract new exact solutions of a wide range of non-linear evolution equations. 相似文献
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Sonika Sahu Mohd. Zahid Ansari Dehi Pada Mondal Chongdu Cho 《Materials Science & Technology》2019,35(7):856-864
In this paper, cenosphere particles embedded in AA2014 aluminium matrix are used to fabricate syntactic foam by stir casting method. The particle size is about 100?µm and foam density is about 1990?kg?m?3. Compression tests at strain rate 0.001/s are performed on foam samples to characterise their mechanical properties which are then used in numerical analysis on commercial finite element analysis software ABAQUS/CAE with isotropic elastic-plastic material model. Experimental and numerical results show good conformity in deformation behaviour with elastic and plateau zones showing average deviations less than 5% and 20%, respectively. Foams showed high yield stress and energy absorption capabilities that can be useful in making blast and impact resistant structures. 相似文献
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As accessing computing resources from the remote cloud inherently incurs high end-to-end (E2E) delay for mobile users, cloudlets, which are deployed at the edge of a network, can potentially mitigate this problem. Although some research works focus on allocating workloads among cloudlets, the cloudlet placement aiming to minimize the deployment cost (i.e., consisting of both the cloudlet cost and average E2E delay cost) has not been addressed effectively so far. The locations and number of cloudlets have a crucial impact on both the cloudlet cost in the network and average E2E delay of users. Therefore, in this paper, we propose the Cost Aware cloudlet PlAcement in moBiLe Edge computing (CAPABLE) strategy, where both the cloudlet cost and average E2E delay are considered in the cloudlet placement. To solve this problem, a Lagrangian heuristic algorithm is developed to achieve the suboptimal solution. After cloudlets are placed in the network, we also design a workload allocation scheme to minimize the E2E delay between users and their cloudlets by considering the user mobility. The performance of CAPABLE has been validated by extensive simulations. 相似文献
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In this letter, we introduce and investigate a new problem referred to as the All Hops Shortest Paths (AHSP) problem. The AHSP problem involves selecting, for all hop counts, the shortest paths from a given source to any other node in a network. We derive a tight lower bound on the worst-case computational complexities of the optimal comparison-based solutions to AHSP. 相似文献
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A cost comparison of balloon angioplasty and stenting versus endarterectomy for the treatment of carotid artery stenosis 总被引:1,自引:0,他引:1
WD Jordan GD Roye WS Fisher D Redden HA McDowell 《Canadian Metallurgical Quarterly》1998,27(1):16-22; discussion 22-4
PURPOSE: Percutaneous transluminal angioplasty with stenting (PTAS) of the carotid artery has been advocated as an alternative treatment for high-grade stenosis. Rationale for this approach includes less morbidity, shorter recovery, and lower cost when compared with carotid endarterectomy (CEA). METHODS: The clinical results and hospital charges of patients who underwent elective treatment for carotid stenosis were reviewed. During a concurrent 14-month period, 218 patients were admitted 229 times for 234 procedures for the treatment of 239 carotid bifurcation stenoses, 109 by PTAS and 130 by CEA. Hospital charges were reviewed for each hospitalization and were categorized according to radiology, operating room, cardiac catheterization laboratory, and all other hospital charges. RESULTS: The combined incidence of postprocedure strokes and deaths were: PTAS, eight strokes (7.7%) and one death (0.9%); CEA, two strokes (1.5%) and two deaths (1.5%). Total hospital charges per admission for the two groups were $30,140 for PTAS and $21,670 for CEA. The average postprocedure length of stay for PTAS was 2.9 days (median, 2 days) and for CEA was 3.1 days (median, 3 days). Cardiac catheterization laboratory charges for the PTAS group were $12,968, whereas the operating room charges for the CEA group were $4263. When hospitalizations that were extended by complications were excluded, the average total charges for the PTAS group (n = 84) dropped to $24,848 (mean length of stay, 1.9 days) and for the CEA group (n = 111) to $19,247 (mean length of stay, 2.6 days). CONCLUSIONS: After evaluating hospital charges, PTAS for the treatment of carotid stenosis cannot currently be justified on the basis of reduced costs alone. With future cost-containing measures, total hospital charges can be reduced in both groups. 相似文献
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Estrogen treatment affects the hepatic synthesis and/or secretion of several proteins involved in clinically important pathological processes such as atherosclerosis, hypertension, and thrombosis. The endocrine regulation of the estrogen receptor (ER) concentration in primary cultures of rat hepatocytes was studied. Human growth hormone (hGH) and dexamethasone (DEX) in combination increased ER concentration 6-fold and ER mRNA levels 2.5-fold. These effects were not significantly different from those observed after treatment with the purely somatogenic bovine growth hormone (GH) in combination with DEX. Treatment with the lactogen ovine prolactin in the presence or absence of DEX did not significantly affect ER or ER mRNA concentrations. Triiodothyronine treatment at the most effective concentration (50 nM) increased ER and ER mRNA levels twofold. Medium supplementation with estradiol (0.1 nM) throughout the experiment did not affect the response to treatment with hGH and DEX. Treatment with high concentrations of ethinylestradiol in combination with hGH and DEX, however, increased the ER level twice as much as hGH and DEX without addition of estradiol or ethinylestradiol, whereas the ER mRNA concentration was the same in both the GH+DEX group and GH+ DEX+ (estradiol or ethinylestradiol) groups. These data indicate the importance of GH in combination with glucocorticoids for the maintenance of ER concentrations in the rat liver. Thyroid hormones may be of some, although minor importance, whereas the data suggest that prolactin is not directly involved in hepatic ER regulation. 相似文献
10.
OBJECTIVE: The most common indication for electroconvulsive therapy (ECT) is major depression. It is less recognized that ECT is effective also in the treatment of acute mania. This article aims to provide a comprehensive and critical review of the literature on the use of ECT for manic patients. METHOD: All published papers in the English language on the use of ECT in acute mania that could be found were reviewed with regard to efficacy, frequency and number of treatments, bilateral versus unilateral electrode placement, predictors of antimanic response, stability of therapeutic response, cognitive consequences, and other relevant issues. RESULTS: The evidence indicates that ECT is associated with remission or marked clinical improvement in 80% of manic patients and that it is an effective treatment for patients whose manic episodes have responded poorly to pharmacotherapy. Manic patients do not require a high frequency or prolonged course of treatments to respond to ECT. The seizure threshold appears to be lower in manic patients than in depressed patients. The issues of relapse following response to ECT, cognitive consequences of ECT, and the relative merits of unilateral versus bilateral ECT in manic patients require further study. CONCLUSIONS: ECT is an effective and safe treatment for acute mania. Remission of mania following ECT reflects a primary therapeutic effect rather than a secondary consequence of an ECT-induced organic brain syndrome. 相似文献