Experimental validation of high-order time integration for non-linear heat transfer problems

An accurate prediction of the temperature distribution in space and time plays an important role in many industrial applications, in particular when phase transformations are involved. In this article the thermo-physical properties of steel 51CrV4 (SAE 6150) are determined and used in numerical simulations. For the simulation of the temperature field a semi-discrete approach is used, consisting of a finite element approximation in space and a high order Runge– Kutta integration in time. Several adaptive high-order time integration method (stiffly accurate diagonally implicit Runge–Kutta methods) are applied and their computational efficiency is investigated. The theoretical rates of convergence are achieved for all problems, including the non-linear case. Whereas the second order accurate method of Ellsiepen with time adaptive step-size control proves to be most efficient. Further, the influence of the material model on the simulation results is studied and the numerical results are verified by experiments. The best correlation of the simulation and experimental data is achieved using temperature-dependent parameters.     

基于K个最近邻点的遗传程序的数字调制样式自动分类

在许多不同的民用和军用领域,调制样式自动分类都是一个非常有趣的问题。本文提出了一种基于K个最近邻点(K-Nearest Neighbor,KNN)的遗传程序(Genetic Programming,GP)算法。该算法采用了基于K个最近邻点的遗传程序,用来识别BPSK、QPSK、16QAM和64QAM调制信号。该算法用高阶累积量作为输入特征,并使用一种分两个阶段的分类方法来改善分类精度。计算机仿真将所提出算法与已有的算法进行了比较,从而证明了该算法的优异性能。     

A simulation model to study the impact of early information on design duration and redesign

In the design process, it is common to utilize early information from precedent activities to shorten the project duration instead of having to wait for the confirmed parameter values to arrive after full analysis. However, the estimated preliminary parameter might be different from that obtained after the full analysis. Consequently, redesign may be needed in downstream activities to correct this discrepancy. Total amount of induced redesign may adversely impact loss of productivity and overall design completion. Furthermore, redesign requires additional resources which may exaggerate the project completion for a project with limited resources. This study presents a simulation model to describe the effect of utilizing early information on redesign and total design duration. The paper characterizes the reduction in project duration while accounting for the impact of redesign through sensitivity studies of the parameters of the simulation model. The sensitivity studies would provide valuable insight that project managers can take into account when utilizing early information in design.     

Venous lesions in Beh?et''s disease

This study examined 117 patients with mild cervical atypia or atypical squamous cells of uncertain significance; it was found that 25% had histologically proven CIN lesions by colposcopically-directed punch biopsy or cone biopsy. 18% were found to have at least CIN 2 lesions and there was 1 case of invasive cancer. These data strongly support the recommendation of early colposcopic referral in patients with mild cervical atypia.     

Fast-acquisition PLL synthesizer using a parallel N-stage cycleswallower with low power consumption and low phase noise

A phase-locked loop (PLL) frequency synthesizer with an N-stage cycle swallower (NSCS) is one of the fastest frequency switching synthesizers, but the use of the NSCS results in high power consumption and phase noise in the UHF band. This paper elucidates these problems and proposes a fast-acquisition PLL synthesizer using a novel type of NSCS with low power consumption and low phase noise. Experimental results confirm that the use of a parallel NSCS and a prescalar results in greatly reduced power consumption and phase noise     

Binding of Ru(II) polyazaaromatic complexes to DNA: A 23Na NMR spin-lattice relaxation study

The possibility of using sodium-23 spin-lattice relaxation rate measurements to probe the interaction modes of Ru11 polyazaaaromatic complexes with DNA is investigated. The following complexes are considered: Ru(phen)3(2+) (phen = 1.10-phenanthroline), Ru(phen)2HAT2+ (HAT = 1,4,5,8,9,12-hexaazatriphenylene), and Ru(diMeTAP)3(2+) (diMeTAP = 2,7-dimethyl-1,4,5,8-tetraazaphenanthrene). The addition of Ru(diMeTAP)3(2+) to a solution of NaDNA leads to a decrease in the sodium-23 spin-lattice relaxation rate (R1) similar to the effect observed upon addition of Mg2+. This indicates that Ru(diMeTAP)3(2+) interacts like Mg2+ with DNA and consequently that the electrostatic interaction dominates the association with DNA, Ru(phen)3(2+) and Ru(phen)2HAT2+ diminish R1 more efficiently than Mg2+, in a manner similar to ethidium bromide, which is known for its intercalation properties. Thus interactions other than electrostatic occur between these two complexes and DNA. These results are in agreement with data obtained from other techniques, according to which Ru(phen)3(2+) and Ru(phen)2HAT2+ are located partially inside the DNA double helix, in contrast to Ru(diMeTAP)3(2+) which remains in the ionic atmosphere around the phosphate backbone.     

Composition-dependence of photoconduction band gap in cadmium zinc phosphate glasses

Photoconduction in cadmium zinc phosphate glasses of various compositions has been measured in the spectral energy range 1.5 to 6.2 eV. With the P₂O₅ percentage remaining fixed at 60 mol %, CdO and ZnO contents have been varied between 0 and 40 mol %. Photocurrents start at about 3.85 eV and rise sharply above 4.5 eV. The optical band gap obtained by the extrapolation of the linear region of the photoresponse curve shows a slow decrease with an increase in the applied field. The optical band gap at a particular applied field decreases with increasing ZnO content. The field-dependence of the optical band gap may be explained in terms of an energy band scheme for non-crystalline solids. The composition-dependence may be due some structural changes in the glasses.