Analysis of Mobility Patterns for Public Transportation and Bus Stops Relocation

Programming and Computer Software - Knowing the mobility patterns of citizens using public transportation is an important issue for modern smart cities. Mobility information is crucial for...     

Dynamic torsional coupling in asymmetric building structures

An approximate method is proposed for the dynamic analysis of torsionally coupled tall building structures by utilizing the properties of their uncoupled counterparts. An exact solution is first given for the particular case in which the lateral and torsional stiffness matrices are uncoupled by same transformation. The method is then applied to a wider class of structures where this condition is only approximately satisfied by reducing the dynamic coupling problem to an approximate two-degrees-of-freedom system. Simple formulae and graphical representations of dynamic magnification of static eccentricity are given. Two numerical examples illustrate the use of the proposed method, checking on its accuracy and comparing its results with seismic code provisions.     

Interactions between engineered nanoparticles (ENPs) and plants: Phytotoxicity, uptake and accumulation

The rapid development and potential release of engineered nanoparticles (ENPs) have raised considerable concerns due to the unique properties of nanomaterials. An important aspect of the risk assessment of ENPs is to understand the interactions of ENPs with plants, an essential base component of all ecosystems. The impact of ENPs on plant varies, depending on the composition, concentration, size and other important physical chemical properties of ENPs and plant species. Both enhancive and inhibitive effects of ENPs on plant growth at different developmental stages have been documented. ENPs could be potentially taken up by plant roots and transported to shoots through vascular systems depending upon the composition, shape, size of ENPs and plant anatomy. Despite the insights gained through many previous studies, many questions remain concerning the fate and behavior of ENPs in plant systems such as the role of surface area or surface activity of ENPs on phytotoxicity, the potential route of entrance to plant vascular tissues and the role of plant cell walls in internalization of ENPs. This article reviewed the current knowledge on the phytotoxicity and interactions of ENPs with plants at seedling and cellular levels and discussed the information gap and some immediate research needs to further our knowledge on this topic.     

Uncertainty Analysis of Memory Based Sensor Validation Techniques

This paper presents an analytical derivation and analysis of the uncertainty of the Multivariate State Estimation Technique (MSET). Like all other nonparametric techniques, MSET uncertainty consists of two parts: bias and variance. Bias is a systematic error in MSET inference and practically not computable and non-removable, but when properly regularized it is usually very small with respect to the variance when properly regularized. Variance, on the other hand, represents variability of the MSET estimate due to random noise in the data and can be estimated in real time. All the derivations and results are obtained for the inferential case. The MSET cost function is also derived which shows that MSET minimizes a weighted least squares cost function with weighting affected by the MSET memory matrix. The parallels between MSET and more traditional kernel techniques, namely kernel regression, are drawn and it is shown that MSET is a special type of kernel regression algorithm. The final section presents the results of the MSET uncertainty analysis for real world data obtained from a commercial nuclear power plant.     

Über die optimierung der synthese von salicylsäure enthaltenden phenol-formaldehyd-harzen

Experiments were carried out for determination of the optimum condition for obtaining phenolformaldehyde resins by condensation of p-tert. butylphenol (PTBPh), formaldehyde (F) and salicylic acid (SS). Symplex lattics design experiment was used for finding out the maximum of the function Y₁ = f₁ (x₁, x₂, x₃) and Y₂ = f₂ ( x₁, x₂, x₃) where Y₁ was the salicylic acid contents, and Y₂ was the resin yield. The corresponding imperfect cubic equations were derived. Their adequity was ascertained by the t-criterion. It was established as a result of the experiments that the contents of the salicylic acid vary in definite limits depending on the components ratio. The constant favourable case in respect to Y₁ did not exceed 18–19%. The optimum corresponds to molar ratio F:TBPh :Sa = 1,0:0,2:0,27 or in mole-% x₁ = 69, x₂ = 13.5, x₃ = 17.5.     

Single-particle sizing from light scattering by spectral decomposition

A Fourier transform was applied to size an individual spherical particle from an angular light-scattering pattern. The position of the peak in the amplitude spectrum has a strong correlation with the particle size. A linear equation retrieved from regression analysis of theoretically simulated patterns provides a relation between the particle size and the location of the amplitude spectrum's peak. The equation can be successfully applied to characterize particles of size parameters that range from 8 to 180 (corresponding to particle sizes that range from 1.2 to 27.2 microm at a wavelength of 0.633 microm). The precision of particle sizing depends on the refractive index and reaches a value of 60 nm within refractive-index region from 1.35 to 1.70. We have analyzed four samples of polystyrene microspheres with mean diameters of 1.9, 2.6, 3.0, and 4.2 microm and a sample of isovolumetrically sphered erythrocytes with a scanning flow cytometer to compare the accuracy of our new method with that of others.     

Polychromatic scintillation

A formula to compute the index of stellar scintillation detected with a finite spectral bandpass and with arbitrary aperture is derived in the limit of weak perturbations. It also applies to differential scintillation (relative fluctuations of light intensity in a pair of apertures), where the effect of finite bandpass turns out to be significant. The new formula is used for measurements of free-atmosphere seeing and low-resolution turbulence profiles with concentric-ring apertures.     

Bridge capacitor bank design and operation

The concept of a bridge capacitor bank installation was presented in a previous paper (see N.G. Andrei et. al., IEEE Trans. Power Systems, vol.8, no.4, p.1463-70, 1993). This paper discusses design and operation aspects related to the installation of a bridge capacitor bank in a substation. The 138/69 kV bridge capacitor bank installation presented by Andrei et. al. is analyzed. An automatic switching control relay scheme for the same test installation is also discussed. The control scheme takes into account the dual effect a bridge capacitor installation has upon the electrical power system: it generates reactive power on the station 138 kV bus and transfers reactive power from the 69 kV to the 138 kV bus. An unbalance protection scheme preventing the cascading type failure of the capacitor units in the 138/69 kV bridge capacitor bank is also presented. An unbalance protection scheme for high voltage, large MVAr size bridge capacitor banks is also discussed. Simple analytical formulas with practical value to evaluate the magnitude and frequency of the voltage transients generated by the energization of a bridge capacitor bank are presented. Recorded switching transient magnitudes and frequencies are compared with calculated values