Comparing central location test and home use test results: Application of a new criterion

Choosing a consumer test methodology is critical for any company sensory scientist. However, we lack tools for comparing the outcome of consumer tests. Here we intended to develop a new comparison criterion based on a concept borrowed from metrology: robustness. We tested this concept with hedonic ratings data obtained from a central location test (CLT) on one hand and from a home use test (HUT) on the other hand. Two fermented milk beverages were tested and both tests were conducted with 240 subjects. The beverages differed in fat and sugar content. The comparison of the CLT and HUT data sets (both in monadic sequential) indicates that the method has a significant effect on the degree of liking. Indeed, the liking scores are lower with CLT than with HUT. Still, both tests lead to the same conclusion that the product with the higher fat and sugar content is significantly more liked. Besides, we developed three graphic representations that illustrate the results stability faced with the decrease in the panel size. These graphs show that CLT yields more robust results than HUT. Additionally the leading role of the panel size is emphasised for both tests. Our data show that the results from the two methods may change as soon as 20 subjects are removed from our original data set. These results that were not unexpected illustrate a fact which is often underestimated in practice.     

Interactivity Improves Usability of Geographic Maps for Visually Impaired People

Tactile relief maps are used by visually impaired people to acquire mental representation of space, but they retain important limitations (limited amount of information, braille text, etc.). Interactive maps may overcome these limitations. However, usability of these two types of maps has never been compared. It is then unknown whether interactive maps are equivalent or even better solutions than traditional raised-line maps. This study presents a comparison of usability of a classical raised-line map versus an interactive map composed of a multitouch screen, a raised-line overlay, and audio output. Both maps were tested by 24 blind participants. We measured usability as efficiency, effectiveness, and satisfaction. Our results show that replacing braille with simple audio-tactile interaction significantly improved efficiency and user satisfaction. Effectiveness was not related to the map type but depended on users’ characteristics as well as the category of assessed spatial knowledge. Long-term evaluation of acquired spatial information revealed that maps, whether interactive or not, are useful to build robust survey-type mental representations in blind users. Altogether, these results are encouraging as they show that interactive maps are a good solution for improving map exploration and cognitive mapping in visually impaired people.     

Cultural differences,experience with social networks and the nature of “true commitment” in Facebook

Formed on an analysis of design practices, the behaviour chain model stipulates that social network designer’s ultimate aim is to encourage users to adopt the social network site by entering a phase of true commitment. During this phase, social network users are driven to connect to known or unknown others by engaging in instrumental uses that create value and content and involve others, while staying active and loyal by investing time in the site. This paper investigates how designer’s intentions, as captured by the behaviour chain model, materialise through users’ reported practices in the social network site Facebook. A total of 423 Facebook users from 5 countries answered a questionnaire that allowed us to examine how 2 user characteristics, experience with the site, and culture, shape the nature of true commitment. Our findings show that experience with the site and even more so, culture, have an effect on users’ motivations for using Facebook, as well as their instrumental uses and the time they invest on the site. This analysis reifies the behaviour chain model by allowing designers to understand how the features they design are embodied in users’ practices.     

Surface characterisation of the Dome Concordia area (Antarctica) as a potential satellite calibration site, using Spot 4/Vegetation instrument

A good calibration of satellite sensors is necessary to derive reliable quantitative measurements of the surface parameters or to compare data obtained from different sensors. In this study, the snow surface of the high plateau of the East Antarctic ice sheet, particularly the Dome C area (75°S, 123°E), is used first to test the quality of this site as a ground calibration target and then to determine the inter-annual drift in the sensitivity of the VEGETATION sensor, onboard the SPOT4 satellite. Dome C area has many good calibration site characteristics: The site is very flat and extremely homogeneous (only snow), there is little wind and a very small snow accumulation rate and therefore a small temporal variability, the elevation is 3200 m and the atmosphere is very clear most of the time. Finally, due to its location, it is frequently within view of many satellites. VEGETATION visible blue channel data (0.43-0.47 μm) of a 716×716 km² area centred on the French-Italian Dome Concordia station, during the 1998-1999, 1999-2000, 2001-2001, and 2001-2002 austral summers were cloud masked and atmospherically corrected. The snow surface Bidirectional Reflectance Distribution Function is very high with little spatial and seasonal variability, which is a major advantage for sensor calibration. The inter-annual variation is found to be very small, proving that the stability of the site is very good.     

Synthesis of ABC miktoarm star block copolymers from a new heterotrifunctional initiator by combination of ATRP and ROP

We described the obtention of well-defined ABC star block copolymers through the use of a new heterotrifunctional initiator. That way, well-defined PCL-arm–PS-arm–PLLA star block copolymers have been synthesized from a heterotrifunctional initiator bearing two hydroxyl groups able to initiate ROP of CL and LLA (using Sn(Oct)₂ as coinitiator) and a bromide function able to initiate ATRP of styrene.     

Realization and simulation of wall shear stress integrated sensors

In this paper we present the impact of hot wire geometry and fluid characteristics on the efficiency of a hot wire to be used as a wall shear stress sensor. Finite differences and finite elements modelling based simulators were used in order to evaluate the thermal performances of hot wire wall shear stress sensor. Several structures were explored including simple conductor or suspended above a cavity (free and sealed with an oxide membrane). It is found out that wire length, wire section and the dimensions of the micro-cavity lying below the hot wire are of fundamental importance on the thermal exchanges occurring between the hot wire and the fluid.     

Engine calibration: multi-objective constrained optimization of engine maps

We present two new approaches to address the optimization problem associated with engine calibration. In this area, the tuning parameters are traditionally determined in a local way, i.e., at each engine operating point, via a single-objective minimization problem. To overcome these restrictions, the first method we propose is able to cope with several objective functions simultaneously in the local formulation. The second method we put forward relies on a global formulation, which allows the whole driving cycle to be taken into account while remaining single-objective. At the practical level, the two methods are implemented by combining various existing techniques such as the LoLiMoT (Local Linear Model Tree) parameterization and the MO-CMA-ES (Multi-Objective Covariance Matrix Adaptation Evolution Strategy) algorithm. A better compromise appears to be achieved on real case applications.     

Cask and plug handling system design in port cell

The ITER maintenance strategy relies partly on the remote transfer of components from vacuum vessel to hot cells. This function will be fulfilled by transfer cask systems.This paper describes the recent design progresses on interfaces in order to increase components handling feasibility by implementing continuous guiding features that avoid cantilevered loads on the in-cask tractor. Also the design has progressed in order to allow generic docking of the casks.When the cask is connected to the port, it becomes part of the machine first confinement boundary, thus it must provide tightness continuity. This high level safety function was one of the main concerns of a finite element analysis study that has been performed to assess the behavior of the whole system. Numerical analysis methodology and results are explained and shown in order to highlight how it has reinforced the knowledge of the system.