42 research outputs found

    A stochastic local search algorithm with adaptive acceptance for high-school timetabling

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    Automating high school timetabling is a challenging task. This problem is a well known hard computational problem which has been of interest to practitioners as well as researchers. High schools need to timetable their regular activities once per year, or even more frequently. The exact solvers might fail to find a solution for a given instance of the problem. A selection hyper-heuristic can be defined as an easy-to-implement, easy-to-maintain and effective 'heuristic to choose heuristics' to solve such computationally hard problems. This paper describes the approach of the team hyper-heuristic search strategies and timetabling (HySST) to high school timetabling which competed in all three rounds of the third international timetabling competition. HySST generated the best new solutions for three given instances in Round 1 and gained the second place in Rounds 2 and 3. It achieved this by using a fairly standard stochastic search method but significantly enhanced by a selection hyper-heuristic with an adaptive acceptance mechanism. © 2014 Springer Science+Business Media New York

    Deep sea tests of a prototype of the KM3NeT digital optical module

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    The first prototype of a photo-detection unit of the future KM3NeT neutrino telescope has been deployed in the deepwaters of the Mediterranean Sea. This digital optical module has a novel design with a very large photocathode area segmented by the use of 31 three inch photomultiplier tubes. It has been integrated in the ANTARES detector for in-situ testing and validation. This paper reports on the first months of data taking and rate measurements. The analysis results highlight the capabilities of the new module design in terms of background suppression and signal recognition. The directionality of the optical module enables the recognition of multiple Cherenkov photons from the same (40)Kdecay and the localisation of bioluminescent activity in the neighbourhood. The single unit can cleanly identify atmospheric muons and provide sensitivity to the muon arrival directions

    Hardware/Software Co-Design of Complex Embedded Systems: An Approach Using Efficient Process Models, Multiple Formalism Specification and Validation via Co-Simulation

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    This paper presents a hardware/software co-design approachwhere different specification languages can be used in parallel, allowingeffective system co-modeling. The proposed methodology introduces a processmodel that extends the traditional spiral model so as to reflect the designneeds of modern embedded systems. The methodology is supported by an advancedtoolset that allows co-modeling and co-simulation using SDL, Statecharts andMATRIXX, and interactive hardware/software partitioning. The effectivenessof the proposed approach is exhibited through two applicati on examples: thedesign of a car window lift mechanism, and the design of a MAC layer protocolfor wireless ATM networks

    A hardware/software co-design methodology for embedded telecommunication systems

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    International audienceThe current paper presents an integrated co-design methodology for embedded telecommunication systems, starting from high-level system modelling down to system implementation. The proposed co-design methodology uses a system specification captured in UML language, translates at a simulatable SDL description used as input to the COSMOS toolset for the generation of a virtual hardware/software prototype. The system's partitioning is achieved interactively in a semi-automatic way, based on COSMOS and its underlying SOLAR format, producing C and VHDL descriptions for the implementation of software and hardware parts respectively. For the co-simulation, synthesis and system implementation parts of the proposed methodology, the CoWare tool has been employed using as front end the generated C and VHDL descriptions produced by COSMOS. The effectiveness of the proposed co-design approach is demonstrated through its application for the design and implementation of the Medium Access Control (MAC) layer and the RF I/F part of the Physical (PHY) layer of the DECT protocol stack

    0.6 [micro sign]m CMOS, 622/155 Mbit/s ATM-SDH/SONET framer IC

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    Design of a Multi-purpose Surface-EMG Readout System for Draft Control Applications

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    This paper presents current work on the design of a multi-purpose surface-electromyography (EMG) readout system that can be used in various draft controlled applications of low-accuracy (e.g. rehabilitation environments for stroke patients, ambient assisted living for elders, remote control of robotic arm). The proposed system interfaces six low-cost and low-power EMG channels exhibiting pm 1.5 mV sensitivity and 400mV output range. The ADC converters of a microcontroller (i.e. Arduino) platform are used to fetch the analog signal from the read-out system. Digital data is verified after ADC conversion using oscilloscope instruments. The microcontroller is programmed to filter the analog signal and identify its rough changes based on continuously adjustable thresholds. The measured data are transmitted in a flexible digital coded format via the microcontroller's network connectivity hardware to the associated control receiver, which in turn decodes it and performs the associated operation as required by the draft-controlled environment. The current consumption ranges from 330uA to 2.9mA per channel, depending on the type of operational amplifier used. © 2019 IEEE
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