Design Thinking and Participation: Lessons Learned from Three Case Studies

This paper examines how design thinking and serious games approaches can be used to support participation through the analysis of three case studies. Indeed we will analyze these approaches in three different contexts: (i) a state-owned multi-utilities company; (ii) a political party; (iii) an information system strategic committee. Our analysis framework relies on the concepts of "perceived usefulness" and "perceived ease of use" and we will use it to discuss the lessons learned. Our main finding is that these approaches really contributing in making complex and abstract matters more "tangible" and thus understandable.participation; design thinking; serious games; case study; perceived usefulness

Commissioning and Evaluation of an Electronic Portal Imaging Device-Based In-Vivo Dosimetry Software.

This study reports on our experience with the in-vivo dose verification software, EPIgray® (DOSIsoft, Cachan, France). After the initial commissioning process, clinical experiments on phantom treatments were evaluated to assess the level of accuracy of the electronic portal imaging device (EPID) based in-vivo dose verification. EPIgray was commissioned based on the company's instructions. This involved ion chamber measurements and portal imaging of solid water blocks of various thicknesses between 5 and 35 cm. Field sizes varied between 2 x 2 cm2 and 20 x 20 cm2. The determined conversion factors were adjusted through an additional iterative process using treatment planning system calculations. Subsequently, evaluation was performed using treatment plans of single and opposed beams, as well as intensity modulated radiotherapy (IMRT) plans, based on recommendations from the task group report TG-119 to test for dose reconstruction accuracy. All tests were performed using blocks of solid water slabs as a phantom. For single square fields, the dose at isocenter was reconstructed within 3% accuracy in EPIgray compared to the treatment planning system dose. Similarly, the relative deviation of the total dose was accurately reconstructed within 3% for all IMRT plans with points placed inside a high-dose region near the isocenter. Predictions became less accurate than < 5% when the evaluation point was outside the treatment target. Dose at points 5 cm or more away from the isocenter or within an avoidance structure was reconstructed less reliably. EPIgray formalism accuracy is adequate for an efficient error detection system with verifications performed in high-dose volumes. It provides immediate intra-fractional feedback on the delivery of treatment plans without affecting the treatment beam. Besides the EPID, no additional hardware is required. The software evaluates local point dose measurements to verify treatment plan delivery and patient positioning within 5% accuracy, depending on the placement of evaluation points

Feasibility of MV CBCT-based treatment planning for urgent radiation therapy: dosimetric accuracy of MV CBCT-based dose calculations.

Unlike scheduled radiotherapy treatments, treatment planning time and resources are limited for emergency treatments. Consequently, plans are often simple 2D image-based treatments that lag behind technical capabilities available for nonurgent radiotherapy. We have developed a novel integrated urgent workflow that uses onboard MV CBCT imaging for patient simulation to improve planning accuracy and reduce the total time for urgent treatments. This study evaluates both MV CBCT dose planning accuracy and novel urgent workflow feasibility for a variety of anatomic sites. We sought to limit local mean dose differences to less than 5% compared to conventional CT simulation. To improve dose calculation accuracy, we created separate Hounsfield unit-to-density calibration curves for regular and extended field-of-view (FOV) MV CBCTs. We evaluated dose calculation accuracy on phantoms and four clinical anatomical sites (brain, thorax/spine, pelvis, and extremities). Plans were created for each case and dose was calculated on both the CT and MV CBCT. All steps (simulation, planning, setup verification, QA, and dose delivery) were performed in one 30 min session using phantoms. The monitor units (MU) for each plan were compared and dose distribution agreement was evaluated using mean dose difference over the entire volume and gamma index on the central 2D axial plane. All whole-brain dose distributions gave gamma passing rates higher than 95% for 2%/2 mm criteria, and pelvic sites ranged between 90% and 98% for 3%/3 mm criteria. However, thoracic spine treatments produced gamma passing rates as low as 47% for 3%/3 mm criteria. Our novel MV CBCT-based dose planning and delivery approach was feasible and time-efficient for the majority of cases. Limited MV CBCT FOV precluded workflow use for pelvic sites of larger patients and resulted in image clearance issues when tumor position was far off midline. The agreement of calculated MU on CT and MV CBCT was acceptable for all treatment sites

Witnessing single-photon entanglement with local homodyne measurements: analytical bounds and robustness to losses

Single-photon entanglement is one of the primary resources for quantum networks, including quantum repeater architectures. Such entanglement can be revealed with only local homodyne measurements through the entanglement witness presented in [Morin et al. Phys. Rev. Lett. 110, 130401 (2013)]. Here, we provide an extended analysis of this witness by introducing analytical bounds and by reporting measurements confirming its great robustness with regard to losses. This study highlights the potential of optical hybrid methods, where discrete entanglement is characterized through continuous-variable measurements

Correction of megavoltage cone-beam CT images of the pelvic region based on phantom measurements for dose calculation purposes.

Megavoltage cone-beam CT (MVCBCT) is an imaging technology that provides a 3D representation of the patient in treatment position. Because it is a form of x-ray tomography, MVCBCT images give information about the attenuation coefficients of the imaged tissues, and thus could be used for dose calculation. However, the cupping and missing data artifacts seen on MVCBCT images can cause inaccuracies in dose calculations. To eliminate these inaccuracies, a correction method specific to pelvis imaging and based on phantom measurements has been devised. Pelvis-shaped water phantoms of three different sizes were designed and imaged with MVCBCT. Three sets of correction factors were created from the artifacts observed in these MVCBCT images by dividing the measured CT number by the predefined CT number for water. Linear interpolation is performed between the sets of correction factors to take into account the varying size of different patients. To compensate for the missing anatomy due to the limited field of view of the MVCBCT system, the MVCBCT image is complemented with the kilovoltage CT (kVCT) image acquired for treatment planning.When the correction method is applied to an anthropomorphic pelvis phantom, the standard deviation between dose calculations performed with kVCT and MVCBCT images is 0.6%, with 98% of the dose points agreeing within +/- 3%.With uncorrected MVCBCT images this percentage falls to 75%. An example of dose calculation performed with a corrected clinicalMVCBCT image of a prostate cancer patient shows that changes in anatomy of normal tissues result in variation of the dose distribution received by these tissues.This correction method enablesMVCBCT images to be used for the verification of the daily dose distribution for patients treated in the pelvis region

Kevoree Modeling Framework (KMF): Efficient modeling techniques for runtime use

The creation of Domain Specific Languages(DSL) counts as one of the main goals in the field of Model-Driven Software Engineering (MDSE). The main purpose of these DSLs is to facilitate the manipulation of domain specific concepts, by providing developers with specific tools for their domain of expertise. A natural approach to create DSLs is to reuse existing modeling standards and tools. In this area, the Eclipse Modeling Framework (EMF) has rapidly become the defacto standard in the MDSE for building Domain Specific Languages (DSL) and tools based on generative techniques. However, the use of EMF generated tools in domains like Internet of Things (IoT), Cloud Computing or Models@Runtime reaches several limitations. In this paper, we identify several properties the generated tools must comply with to be usable in other domains than desktop-based software systems. We then challenge EMF on these properties and describe our approach to overcome the limitations. Our approach, implemented in the Kevoree Modeling Framework (KMF), is finally evaluated according to the identified properties and compared to EMF.Comment: ISBN 978-2-87971-131-7; N° TR-SnT-2014-11 (2014

Séquelles sociales et écologiques du soja transgénique en Argentine

Après des décennies d'instabilité politique et de crise économique, l'Argentine se retrouve au début des années 1990 dans l'impossibilité de rembourser sa dette externe qui atteint plus de 45 milliards de dollars. Pour répondre aux exigences des organismes financiers internationaux, le pays a libéralisé son secteur agricole et encouragé les investissements étrangers. En 1996, l'arrivée sur le marché du soja transgénique, résistant aux herbicides à base de glyphosate, provoqua une véritable révolution dans l'agriculture argentine. Le soja transgénique a connu un succès instantané et s'est vite répandu partout au pays, occupant maintenant 54 % de toutes les terres cultivées. Cette métamorphose de l'agriculture argentine a entraîné d'importantes conséquences sociales et écologiques. Les terres agricoles se concentrent entre les mains des grands propriétaires terriens. Le nombre de fermes a diminué de 30 % et la superficie moyenne des exploitations agricoles est passée de 250 à 538 ha. Le soja transgénique nécessite 30 % moins de main-d’œuvre que les cultures traditionnelles et le chômage agraire atteint des sommets. Entre 1991 et 2001, la population rurale a diminué de 13,5 % dans certaines régions, les petits producteurs délaissent leur terre et tentent leur chance du côté des villes. Les cultures vivrières sont abandonnées pour semer du soja dédié à l'exportation, le prix des denrées alimentaires augmente et on observe une recrudescence des problèmes de malnutrition. Avec l'exploitation à grande échelle du soja transgénique en monoculture, les sols se dégradent. En l'absence de plan de fertilisation adéquat, 3,5 millions de tonnes de nutriments sont puisées annuellement des sols argentins sans être remplacées. La conversion des terres pour l'agriculture sur les sols fragiles a accentué les problèmes d'érosion dans certaines régions. Les forêts cèdent leur place aux cultures de soja. Le taux de déforestation annuel moyen en Argentine, l'un des plus élevé au monde, atteint 1,35 %. Avec la perte et la fragmentation des surfaces forestières, les habitats se dégradent et la biodiversité s'effrite. Entre 1996 et 2005, les émissions annuelles de carbone liées à la déforestation ont atteint 20,875 Gg C/an. La consommation d'herbicide à base de glyphosate est passée de 13,9 millions de litres en 1996 à 200 millions de litres en 2008. Les utilisations répétées du même herbicide ont entraîné l’apparition d’une tolérance chez certaines mauvaises herbes. Le glyphosate est devenu omniprésent dans les écosystèmes, affectant les organismes aquatiques et terrestres et créant des problèmes sanitaires chez les populations humaines. Devant ce portrait inquiétant, des acteurs du secteur public et de la société civile tentent d’implanter des alternatives au modèle du soja transgénique. Le climat est tendu entre les producteurs de soja et le gouvernement central de Buenos Aires. Cependant, plusieurs projets mis sur pied en collaboration avec les agriculteurs démontrent qu’une agriculture rentable, en équilibre avec les écosystèmes et socialement équitable est possible