Energy conservation is crucial in wireless ad hoc sensor network design to increase network lifetime. Since communication consumes a major part of the energy used by a sensor node, efficient communication is important. Topology control aims at achieving more efficient communication by dropping links and reducing interference among simultaneous transmissions by adjusting the nodes’ transmission power. Since dropping links make a network more susceptible to node failure, a fundamental problem in wireless sensor networks is to find a communication graph with minimum interference and minimum power assignment aiming at an induced topology that can satisfy fault-tolerant properties. In this paper, we examine and propose linear integer programming formulations and a hybrid meta-heuristic GRASP/VNS (Greedy Randomized Adaptive Search Procedure/Variable Neighborhood Search) to determine the transmission power of each node while maintaining a fault-tolerant network and simultaneously minimize the interference and the total power consumption. Optimal biconnected topologies for moderately sized networks with minimum interference and minimum power are obtained using a commercial solver. We report computational simulations comparing the integer programming formulations and the GRASP/VNS, and evaluate the effectiveness of three meta-heuristics in terms of the tradeoffs between computation time and solution quality. We show that the proposed meta-heuristics are able to find good solutions for sensor networks with up to 400 nodes and that the GRASP/VNS was able to systematically find the best lower bounds and optimal solutions.
Instead of using a passive AC power grid for low power applications, this paper describes a smart plug for DC networks that is capable of providing the correct power to a device (up to 100W) and that allows for communication between different plugs and monitoring of energy consumption across the DC network using the Ethernet protocol in conjunction with a signal modulator to adapt the signals to the DC network. The ability to monitor consumption on a device-per-device basis allows for closer monitoring of in-house energy use and provides an easily scalable platform to monitor consumption at a macro level. In order to make this paper attractive for the consumer market and easily integrable with existing consumer devices, a generally compatible solution is needed. To meet these demands and to take advantage of the trend of charging consumer devices through USB, we opted for the recently adapted USB Power Delivery standard. This standard allows devices to communicate with the plug and demand a specific voltage and current needed for the device to operate. The purpose of this paper is to give the reader insight in the development of a proof of concept of the smart DC/DC power plug. 10.1109/DUE.2014.6827761
INEDIT creates an open innovation European DIT ecosystem for sustainable furniture co-creation. It channels the creativity of consumers, shapes it through designers' professional skills, and makes it viable by leveraging on the expertise of production specialists in order to deliver sustainable, smart and personalized new products in a shorter time to market. INEDIT intends to demonstrate the capacity to turn the well-known 'Do It Yourself' (DIY) approach applied by individuals within FabLabs into a professional approach named 'Do It Together' (DIT).The DIT approach will be applied by customers and professional producers, especially SMEs, for conveying higher customer satisfaction through customer-driven production. DIT is a novel approach capitalizing on the knowledge, creativity and ideas of design and engineering conceptualized by interdisciplinary stakeholders and sometimes even new actors. It is powered by existing European innovation ecosystems shaping new products across EU countries.INEDIT demonstrates the approach through four cross use cases with high societal impact: sustainable wood panels manufacturing and 3D-printing of wood, 3D printing of recycled plastic and 'smartification'.Sustainability and consideration of individual preferences, especially of women and men, will be our guiding thread. INEDIT addresses societal challenges such as contribution to reduce the amount of produced CO2 in focusing on European-wide production, creation and maintenance of EU-wide job opportunities. This will lead to new business opportunities supported by business model innovation.Moreover, these innovative networked local manufacturing competences and production facilities across the EU will solve ethical concerns within the manufacturing network. INEDIT intends to demonstrate, through its twin - digital and physical - platform, the potential innovation around social manufacturing within the circular economy in designing globally while producing locally.
