scholarly journals A Model-Based Approach to Optimizing Partition Scheduling of Integrated Modular Avionics Systems

Electronics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1281
Author(s):  
Pujie Han ◽  
Zhengjun Zhai ◽  
Lei Zhang
Keyword(s):  
Analytical Methods ◽  
Optimization Problem ◽  
Timed Automata ◽  
System Model ◽  
Parallel Genetic Algorithm ◽  
Statistical Model Checking ◽  
Convex Optimization Problem ◽  
Temporal Partitioning ◽  
Model Based ◽  
Integrated Modular Avionics

The architecture of Integrated Modular Avionics (IMA) provides airborne software with a robust temporal partitioning mechanism, which achieves the reliable fault containment between avionics applications. However, the partition scheduling of an IMA system is a complex nonlinear non-convex optimization problem, making it difficult to solve the optimal temporal allocation for partitions using traditional analytical methods. This paper presents a model-based approach to optimizing the partition scheduling of IMA systems, whose temporal behavior is modeled as a network of timed automata. Given a system model, the optimizer employs a parallel genetic algorithm to search for the optimal partition resource parameters with respect to minimum processor occupancy. For each promising parameter combination, the schedulability constraints and processor occupancy of the system are precisely evaluated by Classical and Statistical Model Checking (i.e., CMC and SMC), respectively. We also apply SMC hypothesis testing to the fast falsification of non-schedulable solutions, thereby speeding up the schedulability verification based on CMC. Two case studies demonstrate that our proposed approach outperforms classical analytical methods on the processor occupancy of typical IMA systems.

scholarly journals Availability Assessment of IMA System Based on Model-Based Safety Analysis Using AltaRica 3.0

Processes ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 117 ◽  
Author(s):  
Haiyong Dong ◽  
Qingfan Gu ◽  
Guoqing Wang ◽  
Zhengjun Zhai ◽  
Yanhong Lu ◽  
...  
Keyword(s):  
Safety Assessment ◽  
Functional Integration ◽  
Safety Analysis ◽  
System Model ◽  
Critical Systems ◽  
Model Based ◽  
Programming Process ◽  
Integrated Modular Avionics ◽  
Availability Assessment ◽  
Logical Architecture

The integrated modular avionics (IMA) system is widely used in all classes of aircraft as a result of its high functional integration and resource utilization in developing advanced avionics systems. However, a series of challenges related to safety assessment exist in the background of the logical architecture for multi-message interactions of the IMA system. Traditional safety assessment methods are mainly based on engineering experience, and are difficult to reuse, incomplete, and even error-prone. Here we propose a method to assess the availability of the IMA system based on the thinking of model-based safety analysis. To aid the proposed method, we implement a tool to generate a AltaRica 3.0 file used to assess the IMA system model. The simulation results show that the proposed method makes the availability assessment fast, efficient, and effective. Moreover, we apply this method to the modification analysis of the IMA system under the condition of satisfying the safety requirement. Our study can enhance the safety assessment of safety-critical systems effectively, assist the design of IMA systems, and reduce the amount of errors during the programming process of the safety model.

scholarly journals Inverse reinforcement learning in contextual MDPs

2021 ◽  
Author(s):  
Stav Belogolovsky ◽  
Philip Korsunsky ◽  
Shie Mannor ◽  
Chen Tessler ◽  
Tom Zahavy
Keyword(s):  
Reinforcement Learning ◽  
Optimization Problem ◽  
Decision Processes ◽  
Inverse Reinforcement Learning ◽  
Convex Optimization Problem ◽  
Reward Function ◽  
Dynamic Treatment Regime ◽  
Markov Decision ◽  
Dynamic Treatment ◽  
Recorded Data

AbstractWe consider the task of Inverse Reinforcement Learning in Contextual Markov Decision Processes (MDPs). In this setting, contexts, which define the reward and transition kernel, are sampled from a distribution. In addition, although the reward is a function of the context, it is not provided to the agent. Instead, the agent observes demonstrations from an optimal policy. The goal is to learn the reward mapping, such that the agent will act optimally even when encountering previously unseen contexts, also known as zero-shot transfer. We formulate this problem as a non-differential convex optimization problem and propose a novel algorithm to compute its subgradients. Based on this scheme, we analyze several methods both theoretically, where we compare the sample complexity and scalability, and empirically. Most importantly, we show both theoretically and empirically that our algorithms perform zero-shot transfer (generalize to new and unseen contexts). Specifically, we present empirical experiments in a dynamic treatment regime, where the goal is to learn a reward function which explains the behavior of expert physicians based on recorded data of them treating patients diagnosed with sepsis.

A model-based approach to measuring denitrification and greenhouse gas production in lakes

2021 ◽  
Author(s):  
Juliet Falco Ajambo-Doherty
Keyword(s):  
Greenhouse Gas ◽  
Atmospheric Pressure ◽  
Schmidt Number ◽  
Spatial Scales ◽  
Gas Production ◽  
System Model ◽  
Biogeochemical Processes ◽  
Model Based ◽  
Temporal And Spatial ◽  
System Metabolism

An existing whole-system model based on changes in dissolved N₂ concentration was modified for lentic systems. Field validations carried out at Christie Lake in Dundas, ON and Turtle Pond in Stoney Creek, ON (Canada). New model inputs included air temperature, atmospheric pressure, relative humidity, wind velocity, and Schmidt number. Mont Carlo analysis was integrated into the model to better constrain error in model estimates of denitrification, whole-system metabolism, and greenhouse gas production. Denitrification rates ranged from -419-4415 µmol N.m-².h-¹ in Christie Lake and from 10-74 µmol N.m-².h-¹ in Turtle Pond. N₂O production ranged from 915-10,635 nmol N.m-².h-¹ in Christie Lake and from -344-131 nmol N.m-².h-¹ in Turtle Pond. The whole-system model allows for the examination of biogeochemical processes at ecologically significant temporal and spatial scales.

Integrated management system model for organization based on quality management and lean production technologies

2021 ◽  
pp. 20-24
Author(s):  
V.V. Silaeva ◽  
◽  
V.P. Semenov ◽  
Keyword(s):  
Quality Management ◽  
Management System ◽  
Integrated Management ◽  
Lean Production ◽  
System Model ◽  
Integrated Management System ◽  
Value Stream ◽  
Model Based ◽  
Production Technologies

The article describes managing the processes of an organization as managing a holistic entity through the characteristics of the value stream. At the same time, the value stream is an activity aimed at creating the value for customer, which is implemented through a system of interconnected processes/operations. The article demonstrates the possibilities of integrating the modern models, standards, methods and tools for quality management and lean production into the processes of an organization in order to achieve the aims. Integrated management system model based on quality management and lean production technologies is presented.

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