23 research outputs found

    An extensible framework for multicore response time analysis

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    In this paper, we introduce a multicore response time analysis (MRTA) framework, which decouples response time analysis from a reliance on context independent WCET values. Instead, the analysis formulates response times directly from the demands placed on different hardware resources. The MRTA framework is extensible to different multicore architectures, with a variety of arbitration policies for the common interconnects, and different types and arrangements of local memory. We instantiate the framework for single level local data and instruction memories (cache or scratchpads), for a variety of memory bus arbitration policies, including: Round-Robin, FIFO, Fixed-Priority, Processor-Priority, and TDMA, and account for DRAM refreshes. The MRTA framework provides a general approach to timing verification for multicore systems that is parametric in the hardware configuration and so can be used at the architectural design stage to compare the guaranteed levels of real-time performance that can be obtained with different hardware configurations. We use the framework in this way to evaluate the performance of multicore systems with a variety of different architectural components and policies. These results are then used to compose a predictable architecture, which is compared against a reference architecture designed for good average-case behaviour. This comparison shows that the predictable architecture has substantially better guaranteed real-time performance, with the precision of the analysis verified using cycle-accurate simulation

    The effect of bias voltage and gas pressure on the structure, adhesion and wear behavior of Diamond Like Carbon (DLC) coatings with Si interlayers

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    In this study diamond like carbon (DLC) coatings with Si interlayers were deposited on 316L stainless steel with varying gas pressure and substrate bias voltage using plasma enhanced chemical vapor deposition (PECVD) technology. Coating and interlayer thickness values were determined using X-ray photoelectron spectroscopy (XPS) which also revealed the presence of a gradient layer at the coating substrate interface. Coatings were evaluated in terms of the hardness, elastic modulus, wear behavior and adhesion. Deposition rate generally increased with increasing bias voltage and increasing gas pressure. At low working gas pressures, hardness and modulus of elasticity increased with increasing bias voltage. Reduced hardness and modulus of elasticity were observed at higher gas pressures. Increased adhesion was generally observed at lower bias voltages and higher gas pressures. All DLC coatings significantly improved the overall wear resistance of the base material. Lower wear rates were observed for coatings deposited with lower bias voltages. For coatings that showed wear tracks considerably deeper than the coating thickness but without spallation, the wear behavior was largely attributed to deformation of both the coating and substrate with some cracks at the wear track edges. This suggests that coatings deposited under certain conditions can exhibit ultra high flexible properties

    Locomotory activity and ion transport in the epithelium of terrestrial snails

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    A hybrid approach to cyber-physical systems verification

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    We propose a performance verification technique for cyber-physical systems that consist of multiple control loops implemented on a distributed architecture. The architectures we consider are fairly generic and arise in domains such as automotive and industrial automation; they are multiple processors or electronic control units (ECUs) communicating over buses like FlexRay and CAN. Current practice involves analyzing the architecture to estimate worst-case end-to-end message delays and using these delays to design the control applications. This involves a significant amount of pessimism since the worst-case delays often occur very rarely. We show how to combine functional analysis techniques with model checking in order to derive a delay-frequency interface that quantifies the interleavings between messages with worst-case delays and those with smaller delays. In other words, we bound the frequency with which control messages might suffer the worst-case delay. We show that such a delay-frequency interface enables us to verify much tigher control performance properties compared to what would be possible with only worst-case delay bounds

    18 Taktyka postępowania u kobiet w ciąży z rozpoznaną ziarnicą złośliwą – doświadczenia własne

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    Praca przedstawia doświadczenia własne i taktykę postępowania u 13 kobiet w ciąży leczonych z rozpoznaniem ziarnicy złośliwej w Centrum Onkologii – Instytut w Warszawie w latach 1987–1998.MetodaW przypadku 3 kobiet z rozpoznaną ziarnicą złośliwą w pierwszym trymestrze ciąży po wykonaniu zabiegów przerwania ciąży przeprowadzono standardową diagnostykę i zastosowano leczenie w zależności od stopnia zaawansowania klinicznego. U 4 chorych w III trymestrze ciąży zdecydowano się na przyjęcie postawy wyczekującej, a następnie po sprowokowaniu czynności porodowej w 36–38 tygodniu ciąży i przeprowadzeniu diagnostyki wdrożono stosowne leczenie. Odmiennie postępowano u 6 chorych w drugim trymestrze ciąży: 3 z nich leczone były napromienianiem z pól wydzielonych z osłoną brzucha i dokładnym oszacowaniem dawki na płód (monitorowanie dawki prowadzono metodą termoluminescencji); pozostałe 3 leczono chemicznie schematem EVA (3–4 kursy przed porodem) z następowym napromienianiem.WynikiWszystkie dzieci urodzone siłami natury bez powikłań w 36–39 tygodniu ciąży. 1 dziecko (matka z grupy III trymestru ciąży) zmarło z powodu wrodzonego zespołu błon szklistych. Pozostałe 9–cioro dzieci urodzonych bez wad rozwojowych, rozwija się prawidłowo i pozostaje pod opieką pediatryczną, (wiek dzieci obecnie 1–10 lat). 1 kobieta zmarła z powodu nawrotu choroby po porodzie, u 1 chorej nawrót po 8 miesiącach obserwacji (obecnie przed planowanym przeszczepem szpiku – w całkowitej remisji). 10 kobiet po leczeniu ziarnicy złośliwej pozostaje w całkowitej remisji w okresie obserwacji 24–116 miesięcy

    Pharmacological analysis of sticky locomotion of terrestrial snails

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