Применение метода контрольных возмущений для определения характерных узлов присоединения комплексной нагрузки при расчетах динамической устойчивости

Рассматривается влияние способа замещения комплексной нагрузки на характер электромеханических переходных процессов в электрических системах (ЭС) от действия больших возмущений. Показано, что установить общие рекомендации относительно способа замещения нагрузки в сложных ЭС затруднительно. Предлагается для опреде­ления характерных узлов нагрузки, оказывающих существенное влияние на характер динамического перехода, применять известный метод контрольных возмущений. Приводятся результаты сравнительных расчетов с использованием предлагаемой методики

Carbon monoxide production from five volatile anesthetics in dry sodalime in a patient model: halothane and sevoflurane do produce carbon monoxide; temperature is a poor predictor of carbon monoxide production

BACKGROUND: Desflurane and enflurane have been reported to produce substantial amounts of carbon monoxide (CO) in desiccated sodalime. Isoflurane is said to produce less CO and sevoflurane and halothane should produce no CO at all. The purpose of this study is to measure the maximum amounts of CO production for all modern volatile anesthetics, with completely dry sodalime. We also tried to establish a relationship between CO production and temperature increase inside the sodalime. METHODS: A patient model was simulated using a circle anesthesia system connected to an artificial lung. Completely desiccated sodalime (950 grams) was used in this system. A low flow anesthesia (500 ml/min) was maintained using nitrous oxide with desflurane, enflurane, isoflurane, halothane or sevoflurane. For immediate quantification of CO production a portable gas chromatograph was used. Temperature was measured within the sodalime container. RESULTS: Peak concentrations of CO were very high with desflurane and enflurane (14262 and 10654 ppm respectively). It was lower with isoflurane (2512 ppm). We also measured small concentrations of CO for sevoflurane and halothane. No significant temperature increases were detected with high CO productions. CONCLUSION: All modern volatile anesthetics produce CO in desiccated sodalime. Sodalime temperature increase is a poor predictor of CO production

Combining Nitrous Oxide with Carbon Dioxide Decreases the Time to Loss of Consciousness during Euthanasia in Mice — Refinement of Animal Welfare?

Carbon dioxide (CO2) is the most commonly used euthanasia agent for rodents despite potentially causing pain and distress. Nitrous oxide is used in man to speed induction of anaesthesia with volatile anaesthetics, via a mechanism referred to as the “second gas” effect. We therefore evaluated the addition of Nitrous Oxide (N2O) to a rising CO2 concentration could be used as a welfare refinement of the euthanasia process in mice, by shortening the duration of conscious exposure to CO2. Firstly, to assess the effect of N2O on the induction of anaesthesia in mice, 12 female C57Bl/6 mice were anaesthetized in a crossover protocol with the following combinations: Isoflurane (5%)+O2 (95%); Isoflurane (5%)+N2O (75%)+O2 (25%) and N2O (75%)+O2 (25%) with a total flow rate of 3l/min (into a 7l induction chamber). The addition of N2O to isoflurane reduced the time to loss of the righting reflex by 17.6%. Secondly, 18 C57Bl/6 and 18 CD1 mice were individually euthanized by gradually filling the induction chamber with either: CO2 (20% of the chamber volume.min−1); CO2+N2O (20 and 60% of the chamber volume.min−1 respectively); or CO2+Nitrogen (N2) (20 and 60% of the chamber volume.min−1). Arterial partial pressure (Pa) of O2 and CO2 were measured as well as blood pH and lactate. When compared to the gradually rising CO2 euthanasia, addition of a high concentration of N2O to CO2 lowered the time to loss of righting reflex by 10.3% (P<0.001), lead to a lower PaO2 (12.55±3.67 mmHg, P<0.001), a higher lactataemia (4.64±1.04 mmol.l−1, P = 0.026), without any behaviour indicative of distress. Nitrous oxide reduces the time of conscious exposure to gradually rising CO2 during euthanasia and hence may reduce the duration of any stress or distress to which mice are exposed during euthanasia

A generic and non-intrusive profiling methodology for SystemC multi-core platform simulation models

The efficient programming of todays multi-core platforms has become a more and more difficult task due to the increasing complexity of the overall system. Especially the lack of an integrated HW/SW co-analysis methodology which allows to explore the behavior of programming models, runtime system and the virtual platform model of the multi-core system leads to the need for new developments in the field of HW/SW co-design tools. In order to support the HW/SW co-design we present a simulation based tracing and profiling methodology for multi-core platforms following a generic and non-intrusive approach supporting easy adaptability, fast applicability and accurate performance measures

Simulation based analysis of memory access conflicts for heterogeneous multi-core platforms

Besides aspects of HW/SW partitioning, resource allocation and mapping, also the optimization of the memory subsystem plays a crucial role during the complex HW/SW co-design and co-optimization process. Especially for memory bound applications, like state of the art video codecs, the memory subsystem has become one of the bottlenecks limiting the performance gains from parallelization and HW accelerated approaches. Memory access conflicts, due to the concurrent access to a shared memory location, are a major source of this bottleneck. To develop counter strategies and to optimize the design, an in-depth analysis of all memory access conflicts is necessary and required. In order to provide this analysis, we propose a flexible tracing and profiling methodology, which provides a timing-accurate memory access conflict analysis for SystemC-based platform simulation models. In a case study this memory access conflict analysis is performed for a heterogeneous platform running a parallel high efficiency video coding (HEVC) intra encoder application. This analysis leads to an optimized design, which reduces the number of memory access conflicts and shows significant performance gains for the target video encoder application

Hand-held terminal for digital video reception

Discusses DVB-H (hand-held digital video broadcasting) systems in Europe, and describes software-based DVB-H video terminals using software for decoding. A portable DVB-H terminal is shown, and response speed of a TV frame decoder is plotted. Reports test results for a software-based TV terminal

Profiling-Based Hardware/Software Co-Exploration for the Design of Video Coding Architectures

The design of embedded hardware/software systems is often subject to strict requirements concerning its various aspects, including real-time performance, power consumption, and die area. Especially for data intensive applications, the number of memory accesses is a dominant factor for these aspects. In order to meet the requirements and design a well-adapted system, the software parts need to be optimized and an adequate system and processor architecture needs to be designed. In this paper, we focus on finding an optimized memory hierarchy for bus-based architectures. Additionally, useful instruction set extensions for application-specific processor cores are explored. For complex applications, this design space exploration is difficult and requires in-depth analysis of the application and its implementation alternatives. Tools are required which aid the designer in the design, optimization, and scheduling of hardware and software. We present a profiling tool for fast and accurate performance, power, and memory access analysis of embedded systems. This paper shows how the tool can be applied for an efficient hardware/software co-exploration within the design flow of processor-centric architectures. This concept has been proven in the design of a mixed hardware/software system with multiple processing units for video decoding