To publish or not to publish? On the aggregation and drivers of research performance

This paper presents a methodology to aggregate multidimensional research output. Using a tailored version of the non-parametric Data Envelopment Analysis model, we account for the large heterogeneity in research output and the individual researcher preferences by endogenously weighting the various output dimensions. The approach offers three important advantages compared to the traditional approaches: (1) flexibility in the aggregation of different research outputs into an overall evaluation score; (2) a reduction of the impact of measurement errors and a-typical observations; and (3) a correction for the influences of a wide variety of factors outside the evaluated researcher's control. As a result, research evaluations are more effective representations of actual research performance. The methodology is illustrated on a data set of all faculty members at a large polytechnic university in Belgium. The sample includes questionnaire items on the motivation and perception of the researcher. This allows us to explore whether motivation and background characteristics (such as age, gender, retention, etc.,) of the researchers explain variations in measured research performance.     

Separation of a triterpenoid saponin mixture from Maesa lanceolata: semipreparative reversed-phase wide pore high performance liquid chromatography with temperature control

A mixture of triterpenoid saponins derived from the dried leaves of Maesa lanceolata was separated, without structure deterioration, in its components. Seven fractions (I-VII) of high molecular weight (1234-1358) saponins were obtained on a semipreparative scale using wide pore reversed-phase high performance liquid chromatography with an acetonitrile trifluoroacetic acid (500:0.3 w/w)-water-trifluoroacetic acid (391:0.3, w/w) gradient from 35 to 56% in 30 min. The mobile phase was cooled in an ice bath (0 degrees C) during chromatography in order to prevent bubble formation and to improve the quality of the separation. Freeze-dried fractions IV, V, VI and VII were further separated using solvent systems developed for each of the fractions. Fourteen pure triterpenoid saponins were isolated in this way and their molar weight determined.     

Interconnect reliability - A study of the effect of dimensional and porosity scaling

A number of challenges linked to the reliability characterization of downscaled back-end-of-line copper/low-k interconnects are covered. Concerning copper reliability, it is shown using early data on 30 nm ½pitch that advanced barrier/seed/plating options can counteract models that predict decreased electromigration performance in smaller dimensions. Regarding stress-induced voiding, it is discussed that porosity scaling negatively influences metal degradation due to increased stress gradients. Also, since copper degradation during high temperature storage tests is driven by different failure mechanisms, it is argued that tests at a wide range of temperatures are needed to characterize stress-induced voiding in copper/low-k systems at normal operating conditions. In addition, it is suggested that the current knowledge on the dependence of interconnect pitches and dielectric porosity on stress in copper lines needs to be taken into account when building finite element models of copper/low-k stacks. This is motivated by highlighting results of our recent study where the copper strain is varied for different copper dimensions and pattern densities. Finally, because the reliability margin of time dependent dielectric breakdown of scaled intermetal dielectrics becomes smaller, it is put forward that understanding the low voltage behaviour of time dependent dielectric breakdown becomes indispensable. A case study using fully passivated MOS capacitors without metallic barrier between the copper and the dielectric is detailed out and differences in current versus time behaviour and distributional shapes between low and high fields are highlighted.     

A ratio or budget benchmark for comparing affordability across countries?

In this article, the methodological strengths and weaknesses of two common housing affordability indicators—the expenditure-to-income ratio and the residual income—are discussed, using data for the Belgian region of Flanders and the Netherlands. Affordability standards are used in order to distinguish the group facing affordability problems. In case of residual income, we use minimum budget standards—excluding housing—that allow for decent participation in society. For the expenditure-to-income ratio, we apply the internationally frequently used 30 % benchmark. Our comparison of the two methods results in a preference for the budget approach. Consequently, we explore the possibilities of applying the budget approach in a comparative context. We conclude by making recommendations for future research.     

Improving customer complaint management by automatic email classification using linguistic style features as predictors

Customer complaint management is becoming a critical key success factor in today's business environment. This study introduces a methodology to improve complaint-handling strategies through an automatic email-classification system that distinguishes complaints from non-complaints. As such, complaint handling becomes less time-consuming and more successful. The classification system combines traditional text information with new information about the linguistic style of an email. The empirical results show that adding linguistic style information into a classification model with conventional text-classification variables results in a significant increase in predictive performance. In addition, this study reveals linguistic style differences between complaint emails and others.     

Gas-solid adsorption of selected volatile organic compounds on titanium dioxide Degussa P25

This paper focuses on the adsorption of gaseous trichloroethylene, toluene and chlorobenzene on the photocatalyst TiO₂ Degussa P25. An optimized EPICS (Equilibrium Partitioning In Closed Systems) methodology was used to study equilibrium partitioning. For the three compounds investigated, equilibrium adsorption was reached within of incubation. Adsorption isotherms, determined at a temperature (T) of and relative humidities (RH) of 0.0% and 57.8% were found to be linear (R²>0.993,n=5), indicating that no monolayer surface coverage was reached in the concentration interval studied ). Within the linear part of the isotherm, the influence of both relative humidity and temperature was investigated in a systematic way and discussed from a thermodynamic point of view. Data analysis resulted in a double linear regression for 22% ?RH?90% and . The equilibrium adsorption coefficient represents the equilibrium concentration ratio and ΔU_ads is the internal energy of adsorption . At RH=0.0%, experimental K values were a factor 5-10 higher than those expected from the regression equation, indicating that another adsorption mechanism becomes important below monolayer surface coverage of TiO₂ by water vapour molecules. Since surface interactions are of primary importance in photocatalytic reactions, this paper contributes to a better understanding of the basic mechanisms of TiO₂ mediated heterogeneous photocatalysis and is an interesting tool for developing optimized mathematical models.