Effect of Microdiversity and Macrodiversity on Average Bit Error Probability in Gamma‐Shadowed Rician Fading Channels

In this letter, we analyze the error performance of a mobile communication system with microdiversity and macrodiversity reception in gamma‐shadowed Rician fading channels for a binary differential phase‐shift keying modulation scheme. Analytical expressions for the probability density function (PDF) and moment‐generating function (MGF) are derived. The average bit error probability can be calculated by averaging the conditional bit error probability over the PDF or using the MGF‐based approach. Numerical results are graphically presented to show the effects of macrodiversity, correlation, number of diversity branches, and severity of both fading and shadowing.     

Fabrication of metallic micromolds by laser and electro-discharge micromachining

A method of creating metallic micromolds with features that have high-aspect ratios is described in this paper. The proposed manufacturing process utilizes laser micromachining to cut the negative two-dimensional profiles of the desired microfeatures and fluidic network patterns on a 100 μm thick brass sheet. The positive relief of the cut pattern is then created by using electro-discharge micromachining (micro-EDM) die-sinking the metallic mask onto a brass substrate. The final substrate with the desired relief pattern becomes the molding tool used for either elastomer casting or thermoplastic hot embossing. To validate the proposed fabrication methodology and evaluate the quality of surface finishes, a brass mold master of a T-channel micromixer (50 μm width, 25 μm height) is developed and multiple replicated devices are cast on this mold using poly-di-methyl-siloxane (PDMS). The surface finish of both the original micromold master and final molded channels on PDMS are measured using an optical profiler and found to have a roughness of approximately 400 nm Ra. The ability of the proposed fabrication technique to create high-aspect ratio features is illustrated by manufacturing a Y-channel micromixer with an aspect ratio of 4. Experimental results are discussed and suggestions for improvement are presented.     

A shift in the perception of lightness on image in digital media due to the manifestation of the simultaneous contrast effect

This paper presents the results of the influence of simultaneous contrast effect on the shift in viewer perception of lightness, depending on the display on which the effect is being evaluated in relation to reproduction. By using simultaneous binocular harmonization technique 55 participants had a task of harmonizing the test primary stimuli presented on two different displays with the referential primary stimuli (that were designed as desaturated samples of 50% RTV, and which are surrounded by desaturated secondary stimuli whose values increase from 10% RTV up to 100% RTV) from the reproduction that was made in digital electrophotography technology. By using one-way repeated measures ANOVA with fisher post-hoc, the strength of the simultaneous contrast effect was presented. Results could be used as a model for predicting the intensity of the simultaneous contrast effect on the design solution used in this paper on relation analogue/digital media.     

FT-NIR光谱法同时测定烟草根、茎、叶中的氮、磷、氯和钾

应用傅里叶变换近红外(FT NIR)光谱法测定了1210个具代表性的烤烟各个生长期的根、茎、叶样品的近红外光谱数据,并采用偏最小二乘法(PLS)分别对实验数据进行处理,建立了预测根茎和烟叶氮、磷、氯和钾等主要营养元素含量的校正模型。通过对模型进行数理统计检验,在显著性水平大于5%的条件下,其预测值与测定值不存在显著性差异。     

Characterization of the solidification path of AlSi5Cu(1–4 wt.%) alloys using cooling curve analysis

Available databases presently used by commercial simulation software packages for the aluminum casting industry usually come with material properties for only a few selected standard alloys. In the case of other alloys with different chemical compositions and refinement or modification treatment, thermal analysis could be an invaluable tool in order to gain necessary properties. The aim of this paper is to characterize the solidification paths of Al-Si5-Cu(1–4) alloys and quantify the amount of solid fraction using cooling curve analysis. The correlation between solid fraction and temperature has been determined using Newtonian and Fourier techniques of base line. Both techniques are also briefly described in this paper. The obtained results have been compared with results obtained using available commercial software (e.g., Pandat and JMatPro).     

Revealing the Interplay between Charge Transport,Luminescence Efficiency,and Morphology in Organic Light‐Emitting Diode Blends

Phosphorescent emissive materials in organic light‐emitting diodes (OLEDs) manufactured using evaporation are usually blended with host materials at a concentration of 3–15 wt% to avoid concentration quenching of the luminescence. Here, experimental measurements of hole mobility and photoluminescence are related to the atomic level morphology of films created using atomistic nonequilibrium molecular dynamics simulations mimicking the evaporation process with similar guest concentrations as those used in operational test devices. For blends of fac‐tris[2‐phenylpyridinato‐C2,N]iridium(III) [Ir(ppy)₃] in tris(4‐carbazoyl‐9‐ylphenyl)amine (TCTA), it is found that clustering of the Ir(ppy)₃ (surface of the molecules within ≈0.4 nm) in the simulated films is directly relatable to the experimentally‐measured hole mobility. Films containing 1–10 wt% of Ir(ppy)₃ in TCTA have a mobility of up to two orders of magnitude lower (≈10^?6 cm² V^?1 s^?1) than the neat TCTA film, which is consistent with the Ir(ppy)₃ molecules acting as hole traps due to their smaller ionization potential. Comparison of the simulated film morphologies with the measured photoluminescence properties shows that for luminescence quenching to occur, the Ir(ppy)₃ molecules have to have their ligands partially overlapping. Thus, the results show that the effect of guest interactions on charge transport and luminescence are markedly different for OLED light‐emitting layers.