The assessment of user-perceived web quality: Application of a satisfaction benchmarking approach

The assessment of website quality is considered as a problem of measuring user satisfaction, in order to analyse user perceptions and preferences. The presented pilot user satisfaction survey concerns the major cellular phone service providers in Greece. The analysis is based on a multicriteria preference disaggregation approach for satisfaction benchmarking analysis and consists of the following parts: (1) the user satisfaction analysis, which concerns the identification of customer preferences and includes the estimation of the relative importance and the demanding level of the different user satisfaction dimensions, and (2) the satisfaction benchmarking analysis, which is mainly focused on the performance evaluation of the competitive organisations against the satisfaction criteria, as well as the identification of the competitive advantages of each company. The results presented in this paper demonstrate how business organisations may locate their position against competition, pinpoint their weak points and determine which website characteristics will improve their global performance.     

Are Real-Time Displays of Benefit in the Singing Studio? An Exploratory Study

This article reports on an exploratory research project to evaluate the usefulness or otherwise of real-time visual feedback in the singing studio. The primary purpose of the work was not to optimize the technology for this application, but to work alongside teachers and students to study the impact of real-time visual feedback technology use on the students' learning experiences. An action research methodology was used to explore the benefit of real-time displays over an extended period. The experimental phase of the work was guided by a Liaison Panel of teachers and academics in the areas of singing, pedagogy, voice science, speech therapy, and linguistic science. Qualitative data were collected from eight students working with two professional singing teachers. The teachers and students acted as co-researchers under the action research paradigm. Teachers and students alike kept journals of their teaching and learning experiences. Singing lessons were observed regularly by the research team, coded for teacher and student behaviors, and all co-researchers were interviewed at the mid- and endpoint of the project. The use of technology had a positive impact on the learning process, and this is evidenced through case study data.     

Acoustic positioning using multiple microphone arrays

Passive acoustic techniques are presented to solve the localization problem of a sound source in three-dimensional space using off-the-shelf hardware. Multiple microphone arrays are employed, which operate independently, in estimating the direction of arrival of sound, or, equivalently, a direction vector from the array's geometric center towards the source. Direction vectors and array centers are communicated to a central processor, where the source is localized by finding the intersection of the direction lines defined by the direction vectors and the associated array centers. The performance of the method in the air is demonstrated experimentally and compared with a state-of-the-art method that requires centralized digitization of the signals from the microphones of all the arrays.     

Control of indirect exciton population in an asymmetric quantum dot molecule

We analyze the problem of coherent population transfer to the indirect exciton state in an asymmetric double semiconductor quantum dot molecule that interacts with an external electromagnetic field. Using the controlled rotation method, we obtain analytical solutions of the time-dependent Schrödinger equation and determine closed-form conditions for the parameters of the applied field and the quantum system that lead to complete population transfer to the indirect exciton state, in the absence of decay effects. Then, by numerical solution of the relevant density matrix equations we study the influence of decay mechanisms to the efficiency of population transfer.     

The 4-aminoantipyrine Method Revisited: Determination of Trace Phenols by Micellar Assisted Preconcentration

The traditional method for phenol analysis based on the oxidizing coupling of 4-aminoantipyrine (4-APP) with phenol in alkaline solution is re-evaluated in this study in combination with micellar assisted preconcentration (cloud point extraction). The method employs the conventional reaction pathway while extraction is facilitated by surfactant based precipitation, during which the nonpolar derivative of 4-AAP-phenol is entrapped in the micelles and concentrated into a surfactant-rich phase. The latter is the re-solubilized and the complex is quantified spectrophotometrically in the presence of a surfactant. Compared to the traditional method the modification proposed offers certain analytical advantages like massive analysis of many samples, lower detection limits and shorter time of analysis. The method was applied in various samples of different origin with satisfactory results.     

Microstuctural analysis and determination of PM10 emission sources in an industrial Mediterranean city

Scientists are interested in knowing more about the control of sources which contribute to environmental pollution. Air pollution has two main sources: anthropogenic and natural sources. The natural contributions to environmental pollution can be assessed, but cannot be totally controlled. while the emissions from the anthropogenic sources can be controlled. These air pollutants can be dispersed and transferred by winds in the atmosphere. The focus area of this study is the Mediterranean basin. The most important winds in this area are the land and sea breezes. Scanning Electron Microscopy (SEM) was applied to characterize the morphology of the PM10 samples in order to identify possible emission sources for the occuring pollution. Energy Dispersive X-ray Spectroscopy (EDS) was performed for the elemental analysis and chemical characterization of the PM10 samples. The analysis showed that the PM10 samples can be divided into three different groups: the samples containing mineral phases, the compounds from combustion processes and the particles emitted from high-temperature processes.      

Camera placement in integer lattices

The camera placement problem concerns the placement of a fixed number of point-cameras on thed-dimensional integer lattice in order to maximize their visibility. We reduce the problem to a finite discrete optimization problem and give a characterization of optimal configurations of size at most 3 ^d . A preliminary version of this work appears in [8]. The research of E. Kranakis was supported by NSERC Grant No. 907002.     

Electrode kinetic phenomena of solid state ionic devices

With the development of functional materials with high ionic and combined ionicelectronic conductivity, the engineering of interfaces became prerequisite. Technological applications demand combinations of materials with different electrical properties to form junctions. The occurring kinetic electrode phenomena play a significant role to the overall performance and may be rate determining. We show here the significance of the equilibration between platinum and the solid electrolyte with respect to the response time in potentiometric oxygen sensors. Fundamental aspects of voltage generation are discussed as well, and the response time is correlated to the equilibration along the contact zone between platinum and the electrolyte. A common problem of potentiometric devices for gas sensing applications is the cross sensitivity to species other than those under detection. The proposed kinetic method based on the theta concept is investigated for selective detection in the presence of a multiple number of complex gases by employing a single electrochemical cell. Information from current-voltage plots is converted to generate complex plane plot for the Fourier coefficients. The various polarizations under the applied electric perturbation are modelled and compared to experimental data for the determination of the rate determining processes.