Minimizing System Modification in an Incremental Design Approach

In this paper we present an approach to mapping and scheduling of distributed embedded systems for hard real-time applications, aiming at minimizing the system modification cost. We consider an incremental design process that starts from an already existing system running a set of applications. We are interested to implement new functionality so that the already running applications are disturbed as little as possible and there is a good chance that, later, new functionality can easily be added to the resulted system. The mapping and scheduling problem are considered in the context of a realistic communication model based on a TDMA protocol

Scheduling and Mapping in an Incremental Design Methodology for Distributed Real-Time Embedded Systems

In this paper we present an approach to mapping and scheduling of distributed embedded systems for hard real-time applications, aiming at a minimization of the system modification cost. We consider an incremental design process that starts from an already existing system running a set of applications. We are interested to implement new functionality such that the timing requirements are fulfilled, and the following two requirements are also satisfied: the already running applications are disturbed as little as possible, and there is a good chance that, later, new functionality can easily be added to the resulted system. Thus, we propose a heuristic which finds the set of already running applications which have to be remapped and rescheduled at the same time with mapping and scheduling the new application, such that the disturbance on the running system (expressed as the total cost implied by the modifications) is minimized. Once this set of applications has been determined, we outline a mapping and scheduling algorithm aimed at fulfilling the requirements stated above. The approaches have been evaluated based on extensive experiments using a large number of generated benchmarks as well as a real-life example

Timing Analysis of the FlexRay Communication Protocol

FlexRay will very likely become the de-facto standard for in-vehicle communications. However, before it can be successfully used for safety-critical applications that require predictability, timing analysis techniques are necessary for providing bounds for the message communication times. In this paper, we propose techniques for determining the timing properties of messages transmitted in both the static (ST) and the dynamic (DYN) segments of a FlexRay communication cycle. The analysis techniques for messages are integrated in the context of a holistic schedulability analysis that computes the worst-case response times of all the tasks and messages in the system. We have evaluated the proposed analysis techniques using extensive experiments. 1

Structural and magnetic properties of nanocrystalline ZnFe2O4 powder synthesized by reactive ball milling

International audienceThe zinc ferrite (ZnFe2O4) has been obtained in nanocrystalline state by reactive milling in a high energy planetary mill from a stoichiometric mixture of oxides (ZnO and α-Fe2O3). A post milling annealing promotes the solid state reaction, improves the ferrite crystalline state and removes internal stresses. The formation of zinc ferrite was studied by X-ray diffraction and magnetic measurements. The chemical homogeneity and morphology of the powders were studied by X-ray microanalysis and scanning electron microscopy. The mean crystallite size after 16 h of milling was found to be 18 ± 2 nm. The lattice parameter of the obtained ferrite depends on the milling time and subsequent annealing treatment. It is lower than that of zinc ferrite obtained by the ceramic method. The evolution of the magnetization versus milling time is discussed in terms of milling induced cations reorganisation into the spinel structure

Synthesis, structural and magnetic characterization of nanocrystalline nickel ferrite-NiFe2O4 obtained by reactive milling

International audienceNanocrystalline nickel ferrite (NiFe2O4) has been synthesized from a stoichiometric mixture of oxides NiO and alpha-Fe2O3 in a high energy planetary mill. An annealing at 350 degrees C, after milling, was used to improve the solid state reaction. The obtained powders were investigated by X-ray diffraction, magnetic measurements, scanning electron microscopy, X-ray microanalysis and differential scanning calorimetry. The particles size distribution was analyzed using a laser particle size analyser. The nickel ferrite begins to form after 4 h of milling and continuously form up to 16 h of milling. The obtained nickel ferrite has many inhomogeneities and a distorted spinel structure. The mean crystallites size at the final time of milling is 9 +/- 2 nm and the lattice parameter increases with increase the milling time. DSC measurements revealed a large exothermic peak associated with cations reordering in the crystalline structure. The magnetization of the obtained powder depends on the milling time and annealing. After the complete reaction between the starting oxides the milling reduces the magnetization of the samples. The magnetization increases after annealing, due to the reorganization of the cations into the spinel structure

Conséquences de l’instabilité morphodynamique liée à l’exploitation du soufre dans le massif volcanique du Calimani (Roumanie)

En Roumanie, la seuleexploitation du soufre en carrière a été ouverte en 1973 dans le secteur du Negoiul Romanesc situé dans la partie centrale du massif du Calimani (Carpates Orientales roumaines). Mais, à cause de la faible rentabilité, cette activité a été arrêtée définitivement en 1997. Actuellement, les versants du cône transformés en carrière et terrils sont très instables, caractérisés par une morphodynamique active  (coulées de débris, glissements de terrain, etc.). Utilisant des orthophotoplans, des cartes topographiques 1/25000 et 1/5000 et les informations provenant des observations de terrain, des sources bibliographiques diverses ou des témoignages, nous avons réalisé une carte actuelle de l’occupation du sol de cette région. Sur cette carte, on observe l’extension spatiale des zones de carrière, des terrils ou de la plateforme industrielle réalisée au détriment des forêts. En aval des terrils, les glissements de terrain et les coulées de débris ont affecté les forêts. Des mesures topographiques ont été effectuées afin de déterminer la vitesse de remplissage des sédiments transportés par les coulées de débris et déposés derrière les barrages construits pour stopper leur progression. Les valeurs obtenues indiquent des vitesses de remplissage de 1430 m3 par an dans le cas du barrage Dumitrelul, respectivement 3250 m3 par an pour le barrage Pinul. Des travaux de réhabilitation des terrils, de la carrière et de la plateforme industrielle ont commencé en juillet 2008, 11 ans après l’arrêt définitif de l’activité minière.In Romania, the onlyopencast sulphur mining was begun in 1973 in the Negoiul Românesc area, situated in the central part of the Călimani massif (Romanian Oriental Carpathians). In 1997 the mining activity ceased for good because of the low profitability. At the moment, the volcanic cone slopes that were turned into quarry and spoil heaps are extremely unstable, and they are characterized by active morphodynamics (debris flows, landslides, etc.). Based on the use of orthophotoplans, topographical maps (1/25000 and 1/5000) and field observations, various bibliographical sources or accounts, we have made a present-day land use map of this area. This map shows the spatial expansion of the quarry, the spoil heaps and the industrial platform that replaced the forest. Downstream the spoil heaps the forests were affected by landslides and debris flows. Topographical measurements have been carried out in order to determine the accumulation rate of the sediments transported by the debris flows and laid beyond the dams that were built in order to stop them. The results show an accumulation rate of 1430 m3 per year for the Dumitrelul dam, respectively 3250 m3 per year for the Pinul dam. In July 2008, 11 years after the definitive cease of the mining activity, rehabilitation work was begun in the spoil heaps, the quarry and the industrial platform.Der einzige Schwefel-Tageabbau in Rumänien wurde im Jahre 1973 im Gebiet des Negoiul Românesc, im zentralen Teil des Călimani-Gebirges (Rumänische Ostkarpaten), eröffnet. Wegen der geringen Rentabilität  wurde jedoch der Abbau 1997 endgültig eingestellt. Z.Z. sind der in einen Steinbruch umgewandelte Kegel und die Halden sehr unbeständig, so dass sie von aktiven morphodynamischen Prozessen erfasst worden sind (Schuttfließen, Erdrutschungen u.a.). Durch Verwendung von Orthophotoplänen, topographischen Karten im Maßstab 1:25.000 und 1: 5.000, durch Geländestudien und Auswertung verschiedener Informationsquellen und Berichte wurde die aktuelle Nutzungskarte des Gebietes erstellt. Man erkennt die Ausdehnung  der Steinbrüche, der Abraumhalden und der Industrieplattformen, die an Stelle des Waldes angelegt wurden. Im unteren Bereich haben Erdrutsche und Schuttströme den Wald verdängt.  Es wurden topographische Messungen gemacht, um die Geschwindigkeit festzustellen, mit der sich die hinter Staumauern angelegten Becken mit Gesteinsschutt auffüllen, die diesen zurückhalten sollen.  Die ermittelten Werte zeigen eine Auffüllgeschwindigkeit von 1430 m³ pro Jahr am Dumitrelul-Stauwehr und 3250  m³ am Pinul Stauwehr. Die Rehabilitierungsarbeiten an den Halden, Steinbrüchen und Industrieplattformen haben im Juli 2008 begonnen, elf Jahre nach der vollständigen Einstellung des Abbaus

Management options in the sudden hearing loss of a diabetic patient

The aim of our paper is to highlight the main therapeutic principles and the management options in the case of a diabetic patient who has had a sudden hearing loss. Mainly, the aim is to underline the sudden hearing loss treatment adjustment of the diabetic patient compared to the non-diabetic patient. By understanding the mechanism of sudden hearing loss in a diabetic patient, namely the impact of glycemic variations and their implication on the microvascular structures of the inner ear, we try to underline the treatment principles and management options of the previously mentioned combined pathologies. Thus, it is necessary to adapt the classes of drugs used in the case of sudden sensorineural hearing loss of the diabetic patient in comparison with the non-diabetic patient, in order not to aggravate or complicate the patient’s functional status. Therefore, the treatment will need to be adapted both by classes of medication and by the type of administration used. Adequate control of the progression, treatment and complications of diabetes mellitus ensures optimal treatment management in case of a sudden hearing loss and therefore interferes with the favorable functional hearing outcomes. The role of this paper is not only to state the therapeutic principles in the case of sudden hearing loss in a diabetic patient, but also to analyze the impact on the management of potential local and systemic risk factors