Design Optimization of Mixed-Criticality Real-Time Applications on Cost-Constrained Partitioned Architectures

Abstract—In this paper we are interested to implement mixed-criticality hard real-time applications on a given heterogeneous distributed architecture. Applications have different criticality levels, captured by their Safety-Integrity Level (SIL), and are scheduled using static-cyclic scheduling. Mixed-criticality tasks can be integrated onto the same architecture only if there is enough spatial and temporal separation among them. We consider that the separation is provided by partitioning, such that applications run in separate partitions, and each partition is allocated several time slots on a processor. Tasks of different SILs can share a partition only if they are all elevated to the highest SIL among them. Such elevation leads to increased development costs. We are interested to determine (i) the mapping of tasks to processors, (ii) the assignment of tasks to partitions, (iii) the sequence and size of the time slots on each processor and (iv) the schedule tables, such that all the applications are schedulable and the development costs are minimized. We have proposed a Tabu Search-based approach to solve this optimization problem. The proposed algorithm has been evaluated using several synthetic and real-life benchmarks. I

Task Mapping and Partition Allocation for Mixed-Criticality Real-Time Systems

Abstract—In this paper we address the mapping of mixed-criticality hard real-time applications on distributed embedded architectures. We assume that the architecture provides both spa-tial and temporal partitioning, thus enforcing enough separation between applications. With temporal partitioning, each application runs in a separate partition, and each partition is allocated several time slots on the processors where the application is mapped. The sequence of time slots for all the applications on a processor are grouped within a Major Frame, which is repeated periodically. We assume that the applications are scheduled using static-cyclic scheduling. We are interested to determine the task mapping to processors, and the sequence and size of the time slots within the Major Frame on each processor, such that the applications are schedulable. We have proposed a Tabu Search-based approach to solve this optimization problem. The proposed algorithm has been evaluated using several synthetic and real-life benchmarks. I

Structure des bandes dans les noyaux de platine (A 182)

SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : TD 81186 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Optimization of Time-Partitions for Mixed-Criticality Real-Time Distributed Embedded Systems

Abstract—In this paper we are interested in mixed-criticality embedded real-time applications mapped on distributed hetero-geneous architectures. The architecture provides both spatial and temporal partitioning, thus enforcing enough separation for the critical applications. With temporal partitioning, each application is allowed to run only within predefined time slots, allocated on each processor. The sequence of time slots for all the applications on a processor are grouped within a Major Frame, which is repeated periodically. We assume that the safety-critical applications (on all criticality levels) are scheduled using static-cyclic scheduling and the non-critical applications are scheduled using fixed-priority preemp-tive scheduling. We consider that each application runs in a separate partition, and each partition is allocated several time slots on the processors where the application is mapped. We are interested to determine the sequence and size of the time slots within the Major Frame on each processor such that both the safety-critical and non-critical applications are schedulable. We have proposed a Simulated Annealing-based approach to solve this optimization problem. The proposed algorithm has been evaluated using several synthetic and real-life benchmarks. Keywords-mixed-criticality; real-time systems; temporal-partitioning I

Assessment of Motivation Level Among Primary Health Care Workers in Tanzania : A Case Study of Muhimbili National Hospital

The main objective of this study was to assess the motivation level among primary health care workers in Tanzania and hence match the motivators with the implementation of performance management in the workplace. The specific objectives were: to identify levels of work motivation of workers, to determine satisfaction levels of workers on incentives and to find out levels of satisfaction of individuals needs. This was a cross sectional study involving a sample of 258 hospital workers. The study was a qualitative one. Stratified sampling was used to randomly pick about 10% of: doctors, nursing staff, auxiliary clinical workers and other administrative and supporting staff. About 58% and 42% of the workers were females and males respectively. Problems facing primary health care workers in Tanzania reported were low salary levels, the frequent unavailability of necessary equipment and consumables to ensure proper patient care, inadequate performance evaluation and feedback, poor communication channels in different organizational units and between workers and management, lack of participation in decision-making processes, and a general lack of concern for workers welfare by the hospital management. Therefore, many workers at all levels in the hospital were not motivated with the tasks they performed due to a variety of factors. That means performance, improved communication at all levels, and introduction of measures to demonstrate concern for the workers’ welfare