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51.
This paper presents a new evolutionary dynamic optimization algorithm, holographic memory-based Bayesian optimization algorithm (HM-BOA), whose objective is to address the weaknesses of sequential memory-based dynamic optimization approaches. To this end, holographic associative neural memory is applied to one of the recent successful memory-based evolutionary methods, DBN-MBOA (memory-based BOA with dynamic Bayesian networks). Holographic memory is appropriate for encoding environmental changes since its stimulus and response data are represented by a vector of complex numbers such that the phase and the magnitude denote the information and its confidence level, respectively. In the learning process in HM-BOA, holographic memory is trained by probabilistic models at every environmental change. Its weight matrix contains abstract information obtained from previous changes and is used for constructing a new probabilistic model when the environment changes. The unique features of HM-BOA are: 1) the stored information can be generalized, and 2) a small amount of memory is required for storing the probabilistic models. Experimental results adduce grounds for its effectiveness especially in random environments. 相似文献
52.
A simplified method for determining the numeric reliability of a complex network is presented. Many methods developed for systems with specific configuration require lengthy transformation or reduction procedure. The reliability of multibridge complex systems with independent components can be evaluated by using conditional probabilities for reliability of the connecting components between the intermediate vertices. An algorithm (COMPLEX) is designed for the reliability computation of multibridge network systems, and a Fortran program is given based on this algorithm. 相似文献
53.
Probabilistic Models of Damaging Deflections for Floor Elements 总被引:1,自引:0,他引:1
In this paper a number of serviceability issues related mainly to excessive deflections of structural floor elements (beams and slabs) are discussed. Field data of serviceability damage caused by excessive deflections of structural floor elements have been collected from various sources and probabilistic models are developed. Current serviceability specifications for allowable deflection limits in Australian, U.S., and other concrete structure codes have been compared against these probabilistic distributions of damaging deflections. Preliminary results confirm that allowable deflection limits in these design codes represent realistic lower-bound values of damaging deflections. 相似文献
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56.
Eman M. E. Dokla Chun‐Sheng Fang Po‐Ting Lai Dr. Samuel K. Kulp Dr. Rabah A. T. Serya Dr. Nasser S. M. Ismail Prof. Khaled A. M. Abouzid Prof. Ching‐Shih Chen 《ChemMedChem》2015,10(11):1915-1923
Previously, we reported the identification of a thiazolidinedione‐based adenosine monophosphate activated protein kinase (AMPK) activator, compound 1 (N‐[4‐({3‐[(1‐methylcyclohexyl)methyl]‐2,4‐dioxothiazolidin‐5‐ylidene}methyl)phenyl]‐4‐nitro‐3‐(trifluoromethyl)benzenesulfonamide), which provided a proof of concept to delineate the intricate role of AMPK in regulating oncogenic signaling pathways associated with cell proliferation and epithelial–mesenchymal transition (EMT) in cancer cells. In this study, we used 1 as a scaffold to conduct lead optimization, which generated a series of derivatives. Analysis of the antiproliferative and AMPK‐activating activities of individual derivatives revealed a distinct structure–activity relationship and identified 59 (N‐(3‐nitrophenyl)‐N′‐{4‐[(3‐{[3,5‐bis(trifluoromethyl)phenyl]methyl}‐2,4‐dioxothiazolidin‐5‐ylidene)methyl]phenyl}urea) as the optimal agent. Relative to 1 , compound 59 exhibits multifold higher potency in upregulating AMPK phosphorylation in various cell lines irrespective of their liver kinase B1 (LKB1) functional status, accompanied by parallel changes in the phosphorylation/expression levels of p70S6K, Akt, Foxo3a, and EMT‐associated markers. Consistent with its predicted activity against tumors with activated Akt status, orally administered 59 was efficacious in suppressing the growth of phosphatase and tensin homologue (PTEN)‐null PC‐3 xenograft tumors in nude mice. Together, these findings suggest that 59 has clinical value in therapeutic strategies for PTEN‐negative cancer and warrants continued investigation in this regard. 相似文献
57.
Nasser A.M. Barakat M.F. Abadir Faheem A. Sheikh Muzafar A. Kanjwal Soo Jin Park Hak Yong Kim 《Chemical engineering journal (Lausanne, Switzerland : 1996)》2010,156(2):487-495
Generally, polymer solution or sol–gel is used to produce electrospun nanofibers via the electrospinning technique. In the utilized sol–gel, the metallic precursor should be soluble in a proper solvent since it has to hydrolyze and polycondensate in the final solution; this strategy straitens the applications of the electrospinning process and limits the category of the electrospinnable materials. In this study, we are discussing electrospinning of a colloidal solution process as an alternative strategy. We have utilized many solid nanopowders and different polymers as well. All the examined colloids have been successfully electrospun. According to the SEM and FE SEM analyses for the obtained nanofiber mats, the polymeric nanofibers could imprison the small nanoparticles; however, the big size ones were observed attaching the nanofiber mats. Successfully, the proposed strategy could be exploited to prepare polymeric nanofibers incorporating metal nanoparticles which might have interesting properties compared with the pristine. For instance, PCL/Ti nanofiber mats exhibited good bioactivity compared with pristine PCL. The proposed strategy can be considered as an innovated methodology to prepare a new class of the electrospun nanofiber mats which cannot be obtained by the conventional electrospinning technique. 相似文献
58.
Muzafar A. Kanjwal Nasser A. M. Barakat Faheem A. Sheikh Myung Seob Khil Hak Yong Kim 《International Journal of Applied Ceramic Technology》2010,7(Z1):E54-E63
In the present study, we are introducing silver-doped titanium oxide nanofibers produced by electrospinning technique. Calcination of dry nanofiber mats consisting of silver nitrate–titanium isopropoxide/PVAc in air at 600°C for 1 h leads to produce Ag-doped titania nanofibers. Two dyes have been invoked to check the photocatalytic ability of the produced nanofibers; methylene blue dihydrate and methyl red. The obtained results indicated that the silver-doped titanium oxide nanofibers can eliminate >92% of the methylene blue dye within 10 min only. In a case of methyl red, almost the dye was decayed (93%) within 3 h. 相似文献
59.
Habib Firouzabadi Nasser Iranpoor Mohammad Gholinejad 《Advanced Synthesis \u0026amp; Catalysis》2010,352(1):119-124
In this article, we have developed a new protocol for the thioarylation of structurally diverse alkyl bromides such as benzyl, cinnamyl, n‐octyl, cyclohexyl, cyclopentyl, and tert‐butyl bromides with aryl iodides, bromides and an activated chloride using thiourea catalyzed by copper(I) iodide in wet polyethylene glycol (PEG 200) as an eco‐friendly medium in the presence of potassium carbonate at 80 and 100 °C under an inert atmosphere. The process is free from foul‐smelling thiols which makes this method more practical for the thioetherification of aryl halides. Another important feature of this method is the variety of alkyl bromides which are commercially available for the in situ generation of thiolate ions with respect to the existing protocols in which the less commercially available thiols are directly used for the preparation of arylthio ethers. 相似文献
60.
Ghasempur S Torabi SF Ranaei-Siadat SO Jalali-Heravi M Ghaemi N Khajeh K 《Environmental science & technology》2007,41(20):7073-7079
Hydroxylated aromatic compounds (HACs) are considered to be primary pollutants in a wide variety of industrial wastewaters. Horseradish peroxidase (HRP) is suitable for the removal of these toxic substances. However, development of a mathematical model and optimization of the HRP-based treatment considering the economical issues by novel methods is a necessity. In the present study, optimization of phenol removal from wastewater by horseradish peroxidase (HRP) was carried out using response surface methodology (RSM) and central composite design (CCD). As the initial experimental design, 2(4-1) half-fraction factorial design (H-FFD) is accomplished in triplicate at two levels to select the most significant factors and interactions in the phenol removal procedure. Temperature (degrees C), pH, concentration of enzyme (unit mL(-1)), and H202 (mM) were determined as the most effective independent variables. Finally, a fourfactor-five coded level CCD, 30 runs, was performed in order to fit a second-order polynomial function to the results and calculate the economically optimum conditions of the reaction. The goodness of the model was checked by different criteria including the coefficient of determination (R2 = 0.93), the corresponding analysis of variance ((Pmodel > F) < 0.0001) and parity plot (r = 0.96). These analyses indicated that the fitted model is appropriate for this enzymatic system. With the assumption that the minimum enzyme concentration was 0.26 unit mL(-1), the analysis of the response surface contour and surface plots defined the optimum conditions as follows: pH = 7.12, hydrogen peroxide concentration 1.72 mM, and 10 degrees C. This work improves phenol removal operation economically by applying minimum enzyme concentration and highest removal in comparison with previous studies. 相似文献