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排序方式: 共有3022条查询结果,搜索用时 15 毫秒
1.
Durmuş Burhanettin Temurtaş Hasan Özyön Serdar 《Neural computing & applications》2020,32(22):17097-17113
Neural Computing and Applications - This study presents the design of a tenth-order multiple feedback Chebyshev low-pass filter (MF-C-LPF). Component selection and gain calculation of filters are... 相似文献
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OVSF codes are used as channelization codes in WCDMA. Due to code blocking property of OVSF codes, the bandwidth available in the system is severely limited. Code reassignments mitigate the impact of the blocking property at the expense of causing delays and decreasing the throughput of the system. Nonblocking OVSF (NOVSF) codes have been proposed to alleviate the adverse effect of code reassignments. This paper presents a code assignment algorithm for NOVSF codes, which does not require any code reassignments. Simulation results show that NOVSF codes achieve better throughput than OVSF codes, even though code reassignments are allowed in the assignments of OVSF codes. 相似文献
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Electroinitiated cationic copolymerisation of indene and styrene was investigated by constant potential electrolysis. Effects of copolymerisation potential and temperature on the copolymer composition and the reactivity ratios are discussed. The reactivity ratios of the monomers were calculated according to the integrated Lewis-Mayo equation. 相似文献
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Instructional texts rewritten by five expert teams: Revisions and retention improvements. 总被引:1,自引:0,他引:1
Britton Bruce K.; Van Dusen Lani; Gulg?z Sami; Glynn Shawn M. 《Canadian Metallurgical Quarterly》1989,81(2):226
700 undergraduates were tested in 3 experiments on original or rewritten versions of 52 instructional texts about Army job tasks, general science, philosophy, and history. Five experts had rewritten various sets of the texts and stated hypotheses about the efficacious features of their revisions. We tested their hypotheses and several others. Recall and recognition tests were given immediately and after a 24-hr delay. Results showed that revisions made by 3 of the 5 experts improved retention of text information. The kind and number of revisions and improvements varied across the text sets. Most expert hypotheses were not supported, and they made many revisions they were declaratively unaware of. Some of our hypotheses about the revision features were supported, but different features were effective for different sets of texts. It was concluded that some experts have effective knowledge about improving instructional text, but it exists primarily in procedural form. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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In this paper, the test results of liquid injection impact on the performance of new alternative refrigerant mixtures such as: R-410A, R-507, R-407C and R-404A are discussed, analysed and presented. The test results were obtained using an air-source heat pump set-up with enhanced surface tubing under various liquid injection ratios. Performance tests were conducted according to the ARI/ASHRAE standards. The performance data demonstrated that as liquid injection ratio increases, compressor head pressure and discharge temperature decrease. This has a positive effect in protecting the compressor. The effect of liquid injection on mixture behaviour varies from one mixture to another depending upon the mixture's composition. Furthermore, liquid injection appears to have a significant influence on R-410A behaviour compared to the other mixtures in question. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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Hasan M.K. Hossain N.M. Naylor P.A. 《Vision, Image and Signal Processing, IEE Proceedings -》2005,152(5):520-526
A novel method for parameter estimation of minimum-phase autoregressive moving average (ARMA) systems in noise is presented. The ARMA parameters are estimated using a damped sinusoidal model representation of the autocorrelation function of the noise-free ARMA signal. The AR parameters are obtained directly from the estimates of the damped sinusoidal model parameters with guaranteed stability. The MA parameters are estimated using a correlation matching technique. Simulation results show that the proposed method can estimate the ARMA parameters with better accuracy as compared to other reported methods, in particular for low SNRs. 相似文献
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The p53 tumor suppressor gene encodes a phosphoprotein which when overexpressed can induce growth arrest at the G1 and G2/M phases of the cell cycle, promote differentiation and apoptosis. This paper demonstrates that p53 can associate with trk tyrosine kinase. Expression of a murine temperature-sensitive (ts) p53 mutant in PC12 cells overexpressing trk (a model system to analyse cellular differentiation and signal transduction induced by NGF) induces morphological changes in the absence of NGF stimulation at 32 degrees C but not at 37 degrees C. In cells differentiated by p53, trk, but not EGFr, was hyperphosphorylated on tyrosine. Furthermore trk was not phosphorylated when expressed in Saos-2 cells (human osteosarcoma cells that lack expression of both endogenous trk and p53) at either temperature. However, transfection of ts p53 into these cells induces trk phosphorylation at 32 degrees C in the absence of NGF stimulation. Association of trk and p53 can be detected in NIH3T3 and PC12 cells co-expressing trk and the ts p53 mutant, in NIH3T3 and PC12 cells transfected with trk alone, and in untransfected PC12 cells, showing that overexpressed and/or endogenous trk associates with endogenous, low levels of p53. These data suggest a novel function for p53 which involves the stimulation of signal transduction pathways (mediating morphological properties of cells), possibly through association with and hyperphosphorylation of trk. 相似文献