Showing papers by "Denis Gillet published in 2013"

Model predictive coordination of autonomous vehicles crossing intersections

Abstract: This paper presents a decentralized model predictive control approach for the coordination of autonomous vehicles at intersections. A linear quadratic optimal controller is introduced for each vehicle with predefined path, in order to minimize energy as well as to pass intersection smoothly. We guarantee collision avoidance by adding linear constraints to the optimization problem. We apply the so-called soft constraints for the collision avoidance problem to reduce the computation time in order to be able to run the simulations in real-time. In addition, the method can take into account crossing of vehicles in platoons by extending the linear quadratic cost functions.

A recommender system for job seeking and recruiting website

Abstract: In this paper, a hybrid recommender system for job seeking and recruiting websites is presented. The various interaction features designed on the website help the users organize the resources they need as well as express their interest. The hybrid recommender system exploits the job and user profiles and the actions undertaken by users in order to generate personalized recommendations of candidates and jobs. The data collected from the website is modeled using a directed, weighted, and multi-relational graph, and the 3A ranking algorithm is exploited to rank items according to their relevance to the target user. A preliminary evaluation is conducted based on simulated data and production data from a job hunting website in Switzerland.

Towards an Online Lab Portal for Inquiry-Based STEM Learning at School

Abstract: Nowadays, the knowledge economy is growing rapidly. To sustain future growth, more well educated people in STEM science, technology, engineering and mathematics are needed. In the Go-Lab project we aim to motivate and orient students from an early age on to study STEM fields in their future educational path by applying inquiry learning using online labs. This paper presents an inquiry learning portal where teachers can discover, use and enhance online labs appropriate for their courses and students can acquire scientific methodology skills while doing experiments using the labs. The Go-Lab portal architecture is presented, which contains a repository of online labs, inquiry learning spaces and complementary services. The paper discusses a first version of the portal and our future plans.

Personalised Learning Spaces and Federated Online Labs for STEM Education at School: Supporting Teacher Communities and Inquiry Learning

Abstract: The European Commission is funding a large-scale research project on federated online laboratories (Labs) for education in Science, Technology, Engineering, and Mathematics (STEM) at School. The main educational focus is on inquiry learning and the main technological one is on personalized learning spaces. The learning spaces are offered through a single European social media portal supporting simultaneously teacher communities and student learning activities. This paper presents the general technical framework devised to support the construction and the exploitation of learning spaces, as well as the federation of online labs

Personalised learning spaces and federated online labs for STEM Education at School

Abstract: The European Commission is funding a large-scale research project on federated online laboratories (Labs) for education in Science, Technology, Engineering, and Mathematics (STEM) at School. The main educational focus is on inquiry learning and the main technological one is on personalized learning spaces. The learning spaces are offered through a single European social media portal supporting simultaneously teacher communities and student learning activities. This paper presents the general technical framework devised to support the construction and the exploitation of learning spaces, as well as the federation of online labs.

Towards Portable Learning Analytics Dashboards

Abstract: This paper proposes a novel approach to build and deploy learning analytics dashboards in multiple learning environments. Existing learning dashboards are barely portable: once deployed on a learning platform, it requires considerable effort to deploy the dashboard elsewhere. We suggest constructing dashboards from lightweight web applications, namely widgets. Our approach allows to port dashboards with no additional cost between learning environments that implement open specifications (Open Social and Activity Streams) for data access and use widget APIs. We propose to facilitate reuse by sharing the dashboards and widgets via a centralized analytics repository.

Identifying influential scholars in academic social media platforms

Abstract: The emergence of social media has created new ways to publish scientific work, foster collaboration, and build professional connections in the research community. The rich data collected in social media platforms has provided new opportunities for assessing scholars' impact other than the traditional citation-based approach. In this paper, we investigate the measures of scholars' influence in academic social media platforms, taking both academic and social impact into account. A real-life dataset collected from Mendeley is used to apply different influence metrics. We first assess the academic influence of scholars based on the scientific impact of their publications using three different measures. Then we investigate their social influence using network centrality metrics. The experiments show that top influencers with high academic impact tend to be senior scholars with many coauthors. Furthermore, academic influence and social influence measures do not strongly correlate with each other, and thus scholars with high academic impact are not necessarily influential from a social point of view. Adding the social dimension could enhance the traditional impact metrics that only take academic influence into account.

Smart device paradigm, Standardization for online labs

Abstract: This paper introduce the smart device paradigm and it usage to streamline the development of the next generation of online labs where more intelligence is placed at the server side and little or no assumption is made about the client. The requirements, the standards and protocols for implementation are presented. Finally a possible evolution toward Massive Open Online Labs (MOOLs) is discussed.

Personal learning environments as enablers for connectivist MOOCs

Abstract: This paper presents how platforms initially designed to enable the construction of personal learning environments can help teachers and learners to aggregate their own MOOCs from resources freely available in the Cloud under Creative Commons licenses. Compare to the mainstream MOOC platforms like Coursera or EdX which are basically learning management systems open to external students, the proposed solution offers built-in social media features to boost opportunistic interaction and informal exchanges between students.

SpeakUp --- A Mobile App Facilitating Audience Interaction

Abstract: A dynamic student-teacher interaction during class is an important part of the learning experience. However, in regular class settings and especially in large classrooms, it is a challenging task to encourage students to participate as they tend to be intimidated by the size of the audience. In this paper, in order to overcome this issue, we present SpeakUp, a novel context-aware mobile application supporting the social interactions between speakers and audiences through anonymous messaging and a peer rating mechanism. Context-awarness is achieved by bounding interactions in space and time using location-based authorization and message boards with limited lifetime. Anonymity is used as an icebreaker, so students dare writing down any question that pops in their heads. Peer rating is used to make it easy for teachers to access the most relevant ones and address them. We performed an evaluation with 140 students over five four-hour lessons that indicate that SpeakUp is easy to use and is perceived as useful.

Collision Avoidance in Next-generation Fiber Positioner Robotic System for Large Survey Spectrograph

Abstract: Some of the next generation massive spectroscopic survey projects, such as DESI and PFS, plan to use thousands of fiber positioner robots packed at a focal plane to quickly move in parallel the fiber-ends from the previous to the next target points. The most direct trajectories are prone to collision that could damage the robots and impact the survey operation. We thus present here a motion planning method based on a novel decentralized navigation function for collision-free coordination of fiber positioners. The navigation function takes into account the configuration of positioners as well as the actuator constraints. We provide details for the proof of convergence and collision avoidance. Decentralization results in linear complexity for the motion planning as well as dependency of motion duration with respect to the number of positioners. Therefore the coordination method is scalable for large-scale spectrograph robots. The short in-motion duration of positioner robots (~2.5 seconds using typical actuator constraints), will thus allow the time dedicated for observation to be maximized.

Cloud-Savvy contextual spaces as agile personal learning environments or informal knowledge management solutions

Abstract: This paper presents how advanced social media platforms can be exploited to construct and share contextual spaces enabling the instantiation of agile personal learning environments or informal knowledge management solutions. The usefulness of open plugins to collect resources from the cloud in such dedicated contextual spaces is discussed. The mechanisms for the personalization of spaces from an interaction point of view once populated with resources and their sharing across platforms are also detailed. Results are illustrated with the case of the Graasp platform developed in the framework of European research projects in Technology Enhanced Learning.

Reinventing Mobile Community Computing and Communication

Abstract: In less than a decade, smartphones and mobile applications spread like wildfire and dramatically improved aspects of our professional and private lives, from efficiency to safety. However, these applications are still in their infancy and mostly provide mobile versions of online Internet services or arcade games. With the exception of simple location-based query applications, context-awareness is largely ignored. However, it is not hard to imagine advanced mobile social networking applications -- SNAPPs for short -- that could proactively assist users in everyday tasks, improving their quality of life. Such services would require massive data collection, processing and communication between mobile devices. Unfortunately, the current centralised communication paradigm represents a major barrier to such intense networking. In this paper, we claim that a fundamental paradigm shift in communication is required to allow such application to see the light of day. The paper claims that such a shift is possible and that it resides in moving towards decentralised communication by taking advantage of the largely untapped network, storage and processing power capabilities offered by idle mobile devices. The paper presents and discusses a number of research questions that must be addressed in order to achieve this paradigm shift.

Widget and smart devices. A different aproach for online learning scenarios

Abstract: A vast number of learning content and tools can be found over Internet. Currently, most of them are ad-hoc solutions which are developed for a particular learning platform or environment. New concepts, such as Widgets, Smart devices, Internet of Thing and learning Clouds, are ideas whose goals is the creation of shareable online learning scenarios over different devices and environments.