Effect of suspended particulate-size distribution on the backscattering ratio in the remote sensing of seawater

Mie theory is used to study the influence of the particle-size distribution (PSD) on the backscattering ratio for case 1 and 2 waters. Several in situ measured PSDs from coastal water and the open ocean, representing typical case 2 and 1 waters, were used in this investigation. Calculation of the backscattering ratio requires integration of the PSD over a much broader size range than is usually measured. Consequently extrapolation from fitted data is necessary. To that purpose the measured data are fitted with hyperbolic (Junge) and the two-component model of the PSD. It is shown that the result of extrapolation, hence the backscattering ratio, critically depends on the chosen PSD model. For a particular PSD model the role of submicrometer particles and the applied integration limits on the backscattering ratio is discussed. The use of the hyperbolic PSD model largely overestimates the number of small (submicrometer) particles that significantly contribute to backscattering and consequently leads to an erroneously high backscattering ratio. The two-component model proves to be an adequate PSD model for use in backscattering/scattering calculations providing satisfactory results complying with experimental data. The results are relevant for the inversion of remotely sensed data and the prediction of optical properties and the concentration of phytoplankton pigments, suspended sediment, and yellow substance.     

Neural network approach to background modeling for video object segmentation.

This paper presents a novel background modeling and subtraction approach for video object segmentation. A neural network (NN) architecture is proposed to form an unsupervised Bayesian classifier for this application domain. The constructed classifier efficiently handles the segmentation in natural-scene sequences with complex background motion and changes in illumination. The weights of the proposed NN serve as a model of the background and are temporally updated to reflect the observed statistics of background. The segmentation performance of the proposed NN is qualitatively and quantitatively examined and compared to two extant probabilistic object segmentation algorithms, based on a previously published test pool containing diverse surveillance-related sequences. The proposed algorithm is parallelized on a subpixel level and designed to enable efficient hardware implementation.     

The role of nonuniform dielectric permittivity in the determination of heterojunction band offsets by C–V profiling through isotype heterojunctions

Up to now, C–V profiling through isotype heterojunctions has been performed assuming a uniform dielectric permittivity throughout the heterostructure. We extend the interpretation of C–V data to the case of a semiconductor with position-dependent dielectric permittivity, and we show that the variation of the dielectric permittivity across an isotype heterojunction interface has no effect on the determination of the heterojunction band discontinuity and the interface charge density.     

Comparison of different modes of excitation in X-ray emission spectroscopy in the detection of trace elements in coal and coal ash

Three different modes of sample excitation in X-ray emission spectroscopy were used in trace element analysis of coal and coal ash: proton beam, Mo X-ray tube and radioactive sources ⁵⁷Co and ¹⁰⁹Cd. The results of analysis are presented and methods and their possibilities are compared in order to indicate the most appropriate technique for the particular purpose.     

Tool wear estimation using an analytic fuzzy classifier and support vector machines

A new type of continuous hybrid tool wear estimator is proposed in this paper. It is structured in the form of two modules for classification and estimation. The classification module is designed by using an analytic fuzzy logic concept without a rule base. Thereby, it is possible to utilize fuzzy logic decision-making without any constraints in the number of tool wear features in order to enhance the module robustness and accuracy. The final estimated tool wear parameter value is obtained from the estimation module. It is structured by using a support vector machine nonlinear regression algorithm. The proposed estimator implies the usage of a larger number and various types of features, which is in line with the concept of a closer integration between machine tools and different types of sensors for tool condition monitoring.     

Laser machining of GaN-on-diamond wafers

The commercialization of gallium-nitride microwave circuits on diamond substrates requires chip-dicing technology and via formation process compatible with standard semiconductor processes. This paper discusses issues related to dicing and drilling of GaN-on-diamond wafers for RF power transistor applications (die size < 1 mm²) using laser micromachining.     

Why we believe the computer when it lies

A survey was conducted on the sample of 60 future engineers in order to determine whether inadequate computer feedback changes the supposed success in problem solving and whether personality traits are also in the function of this change. The research results showed that personality traits fail to influence the formation of beliefs on success. Results also showed that the situation of inadequate feedback results in the changes in beliefs, on the success in problem solving and that the change is in the function of personality traits and established experience-based behavior strategies. In this situation respondents do not form any strategy for attitude conservation, but inadequate computer feedback significantly reduces estimation of their success regardless to the fact that the objective achievement is not reduced.     

Modeling and measurement of cross‐talk transmission between coupled lines

In multiwire cables, high‐frequency signals can, and do, propagate not only by direct conduction over a pair of wires the signal was inserted to but also by electromagnetic coupling between adjacent transmission lines formed out of multiple wire pairs, too. Thus, it is useful to be able to measure relevant parameters, dependent of cable geometry and isolation material, that would enable modeling of cross‐talk propagation. In this article, signal propagation between ports of two coupled lines is first theoretically analyzed using z‐parameters. Then, the physical quantities needed for calculation of z‐parameters in systems with electrically long cable sections were defined and measured, and the results were verified against measurements performed on real cables. Copyright © 2014 John Wiley & Sons, Ltd.     

The potential of fission nuclear power in resolving global climate change under the constraints of nuclear fuel resources and once-through fuel cycles

Nuclear fission is receiving new attention as a developed source of carbon-free energy. A much larger number of nuclear reactors would be needed for a major impact on carbon emission. The crucial question is whether it can be done without increasing the risk of nuclear proliferation. Specifically, can a larger nuclear share in world energy production, well above the present 6%, be achieved in the next few decades without adding the proliferation-sensitive technologies of reprocessing spent fuel and recycling plutonium to the problems of the unavoidable use of enrichment technology? The answer depends on the available uranium resources. We first looked for the maximum possible nuclear build-up in the 2025–2065 period under the constraints of the estimated uranium resources and the use of once-through nuclear fuel technology. Our results show that nuclear energy without reprocessing could reduce carbon emission by 39.6% of the total reduction needed to bring the WEO 2009 Reference Scenario prediction of total GHG emissions in 2065 to the level of the WEO 450 Scenario limiting global temperature increase to 2 °C. The less demanding strategy of the nuclear replacement of all non-CCS coal power plants retiring during the 2025–2065 period would reduce emission by 26.1%.     

Telecommunication liberalization and economic development in European countries in transition

Developed and widely available telecommunications services are regarded as key enablers of a new economy. In Eastern European countries in transition, investment in telecommunications is generally perceived as a stimulus for economic growth. We investigate empirical correlation and Granger causality between certain indicators of telecommunications activity and economic growth. The indicators include total investment in the telecommunications sector and other parameters such as the penetration rate of services. We also propose additional indicators that may describe telecommunications sector development better than traditional, fixed, telephony-based measures. This is due to the migration of users from fixed to mobile networks, and from basic to broadband Internet access in the last few years. In the near future one also can expect broadband Internet users to move to mobile network infrastructure.