Exploring how users engage with hybrid process artifacts based on declarative process models: a behavioral analysis based on eye-tracking and think-aloud

Process design artifacts have been increasingly used to guide the modeling of business processes. To support users in designing and understanding process models, different process artifacts have been combined in several ways leading to the emergence of the so-called “hybrid process artifacts”. While many hybrid artifacts have been proposed in the literature, little is known about how they can actually support users in practice. To address this gap, this work investigates the way users engage with hybrid process artifacts during comprehension tasks. In particular, we focus on a hybrid representation of DCR Graphs (DCR-HR) combining a process model, textual annotations and an interactive simulation. Following a qualitative approach, we conduct a multi-granular analysis exploiting process mining, eye-tracking techniques, and verbal data analysis to scrutinize the reading patterns and the strategies adopted by users when being confronted with DCR-HR. The findings of the coarse-grained analysis provide important insights about the behavior of domain experts and IT specialists and show how user’s background and task type change the use of hybrid process artifacts. As for the fine-grained analysis, user’s behavior was classified into goal-directed and exploratory and different strategies of using the interactive simulation were identified. In addition, a progressive switch from an exploratory behavior to a goal-directed behavior was observed. These insights pave the way for an improved development of hybrid process artifacts and delineate several directions for future work.

     

Flow characterization in T-shaped and cross-shaped micromixers

The understanding of physical phenomena such as flow behaviour and mass transfer performance is needed in order to develop appropriate micromixers for industrial or biomedical applications. In this article, the flow behaviour of the T-shaped and the cross-shaped micromixers with square cross-section are studied through numerical and experimental investigations. The comparisons are based on identical treated fluxes. From the particle image velocimetry (PIV) measurements, the flow topologies in the T-shaped and cross-shaped micromixers are very different. After liquid impact, it is observed that the vortex structures cover a longer part of the outlet channel in the case of the cross geometry. This result indicates that the cross-shaped micromixer could improve the mixing process in comparison with the micromixers having T geometry. A second experimental technique has been used, the electrochemical one, involving microelectrodes placed at several wall positions of the cross-shaped micromixer. The electrochemical method can locally characterize the formation of swirling flows. The high values of wall shear rate, in the impact zone, confirm the near wall disturbance created by the impingement of the flow and also the appearance of vortices that could enhance fluid mixing.     

Separation of Si and SiC from Photovoltaic Industry Waste. Recycling of SiC in Production of Cu2O-SiC Powder

Silicon - Silicon ingot cutting process generates slurry waste which mainly contains lubricant oil, silicon and silicon carbide particles. In this study, slurry waste was the subject of a primary...     

Assessment of ignition hazard in turbulent flammable gas mixers combining a Lagrangian approach and large eddy simulation

In this article, a Lagrangian approach is adopted to assess both mixing efficiency and ignition hazard of fuel/oxygen flammable gas mixing in a jets-in-cross-flow configuration. Large eddy simulation is used to provide the unsteady fields of turbulent gas mixing. To achieve statistical reliability of the fluid dynamics field, such as velocity, pressure, temperature, and chemical composition, a large number of Lagrangian markers are dumped into the inlet streams of the mixer and their trajectories are determined during the numerical simulation. Those trajectories are stored in a file processed afterward to build up the probability density functions of the fuel molar fraction of Lagrangian markers gauging both mixer efficiency and safety. Flammability limits provided by H.F. Coward and G.W. Jones [U.S. Bur. Mines Bull. 503 (1952)] and autoignition delays from a detailed kinetics scheme are required to define the hazard range. Processing the marker trajectory file allows the calculation of relevant Lagrangian properties such as (i) the critical residence time in flammability areas for the ignition case and (ii) the marker Damköhler number for the autoignition case, both including the subgrid turbulence effects. The latter are accounted for by assuming a presumed beta shape for the large eddy probability density function of subgrid fluctuations of mixture fraction. Analysis of all marker trajectories leads to a computation of global probability density functions of Lagrangian properties that characterize mixer safety.     

Soft Computing Techniques for Classification of Voiced/Unvoiced Phonemes

A method that uses fuzzy logic to classify two simple speech features for the automatic classification of voiced and unvoiced phonemes is proposed. In addition, two variants, in which soft computing techniques are used to enhance the performance of fuzzy logic by tuning the parameters of the membership functions, are also presented. The three methods, manually constructed fuzzy logic (VUFL), fuzzy logic optimized with genetic algorithm (VUFL-GA), and fuzzy logic with optimized particle swarm optimization (VUFL-PSO), are implemented and then evaluated using the TIMIT speech corpus. Performance is evaluated using the TIMIT database in both clean and noisy environments. Four different noise types from the AURORA database—babble, white, restaurant, and car noise—at six different signal-to-noise ratios (SNRs) are used. In all cases, the optimized fuzzy logic methods (VUFLGA and VUFL-PSO) outperformed manual fuzzy logic (VUFL). The proposed method and variants are suitable for applications featuring the presence of highly noisy environments. In addition, classification accuracy by gender is also studied.     

A study of tri(ethylene glycol)-substituted trimethylsilane (1NM3)/LiBOB as lithium battery electrolyte

Silicon-based electrolyte has emerged as a primary candidate for the development of large lithium-ion batteries for electric vehicle (EV) and other systems in which safety is a primary consideration. Comparing to the electrolyte used in the conventional lithium-ion batteries, which are flammable, volatile, and highly reactive organic carbonate solvents, silicon-based electrolytes are thermally and chemically stable, less flammable and environmental benign. Tri(ethylene glycol)-substituted trimethylsilane (1NM3) was identified as a focus of investigation due to its high conductivity and low viscosity. We present the results of a systematic investigation of the 1NM3-based electrolytes with lithium bis(oxalate)borate (LiBOB) salt, including temperature dependent ionic conductivity and lithium cell performance. Lithium-ion cell with LiNi_1/3Co_1/3Mn_1/3O₂ as the positive electrode and MAG graphite as the negative electrode has shown excellent cyclability using 1NM3-LiBOB as electrolyte.     

Enhanced electrochemical performance of carbon-LiMn1−xFexPO4 nanocomposite cathode for lithium-ion batteries

4 V-class olivine C-LiMn_1−xFe_xPO₄ (x = 0 and 0.15) are synthesized by ultrasonic pyrolysis followed by ball milling with AB carbon to evaluate the doping effect of iron. The C-LiMn_0.85Fe_0.15PO₄ shows excellent rate capability having discharge capacity of 150 mAh g⁻¹ at 0.5C-rate and 121 mAh g⁻¹ at 2C-rate. The capacity retention of the C-LiMn_0.85Fe_0.15PO₄ is 91% after 50 cycles at 55 °C whereas C-LiMnPO₄ is limited to 87%. The improved electrochemical performance of the C-LiMn_0.85Fe_0.15PO₄ electrode is attributed to the enhanced electrical conductivity caused by tighter binding on the carbon particles with the LiMn_0.85Fe_0.15PO₄ primary particles as well as by the surface coating of carbon on the primary particles.     

Comparative study of ITO and FTO thin films grown by spray pyrolysis

Tin doped indium oxide (ITO) and fluorine doped tin oxide (FTO) thin films have been prepared by one step spray pyrolysis. Both film types grown at 400 °C present a single phase, ITO has cubic structure and preferred orientation (4 0 0) while FTO exhibits a tetragonal structure. Scanning electron micrographs showed homogeneous surfaces with average grain size around 257 and 190 nm for ITO and FTO respectively.The optical properties have been studied in several ITO and FTO samples by transmittance and reflectance measurements. The transmittance in the visible zone is higher in ITO than in FTO layers with a comparable thickness, while the reflectance in the infrared zone is higher in FTO in comparison with ITO. The best electrical resistivity values, deduced from optical measurements, were 8 × 10⁻⁴ and 6 × 10⁻⁴ Ω cm for ITO (6% of Sn) and FTO (2.5% of F) respectively. The figure of merit reached a maximum value of 2.15 × 10⁻³ Ω⁻¹ for ITO higher than 0.55 × 10⁻³ Ω⁻¹ for FTO.     

Dissolving pulps from Egyptian bagasse. II. Low temperature cooking

Bagasse was pulped by the prehydrolysis-soda process. Increasing the concentration during prehydrolysis or pulping had a favourable effect on pulp properties. Further improvement in these properties was attained when the increase in concentration was accompanied by lowering the temperature. The effects of increasing the concentration and lowering the temperature of prehydrolysis and pulping were compared.