The Orbital Channel Resource Control on Non-Markov Priority Systems of Mass Service Basis. Part 2. Dispatch Method

The article develops a methodology for scheduling an orbital channel resource with operational priority assignment based on the calculation of the parameters of a non-Markov service model with a limited residence time of a request in the system, which differs from known methods in that it takes into account the priority of various network subscribers, taking into account the high dynamics of their movement and the average waiting time in the service system with priority in the allocation of the orbital channel resource of the satellite command-relay system. The analysis of the influence of service quality indicators of information data flows is carried out.It is shown that the developed method of priority scheduling makes it possible to meet the requirements for the quality of service. A complex of experimental studies was carried out, which showed the possibility of ensuring the required level of stability with the deterioration in difficult conditions of radio electronic equipment, which made it possible to formulate practical proposals for improving the complex of coordination and distribution of resources of in the satellite command relay system.

A Novel PageRank Based Fault Handling Strategy for Workflow Scheduling in Cloud Data Centers

Unexpected faults result in unscheduled cloud outage, which negatively affects the completion of workflow tasks in the cloud. This paper presents a novel PageRank based fault handling strategy to rescue workflow tasks at the faulty data center. The proposed approach uses a holistic view and considers the task attributes, the timeline scenario, and the overall cloud performance. A priority assignment system is developed based on the modified PageRank algorithm to prioritise workflow tasks. A Min-Max normalization method is applied to select the target data center and match the timeline at this data center. Additionally, a dynamic PageRank-constrained task scheduling algorithm is proposed to generate the task scheduling solution. The simulation results show that the proposed approach can achieve better fault handling performance, measured by task resilience ratio, workflow resilience ratio and workflow continuity ratio, in both the traditional 3-replica and the image backup cloud environment.

Relationship between workers’ return to work, job retention and income in industrial accidents in Korea: a longitudinal study

ObjectiveThis study aims to compare workers’ income before and after an occupational injury, with regard to return to work and job retention, over a period of 5 years.DesignThis study was designed as a longitudinal study.SettingThe Panel Study of Workers’ Compensation Insurance (PSWCI) survey targeted workers involved in industrial accidents for which medical care was terminated in the year 2012.ParticipantsThe panel study was conducted on a final sample of 2000 workers who were selected proportionally by region (nine regions) after priority assignment by disability rating (six levels). A total of 1458 workers were finally included in this study.MethodsThis study used data from the first to fifth PSWCI. To identify the effect on income after occupational injury considering return to work and job retention, we used the generalised estimating equation.ResultsIn regard to workers’ return to work, the OR that income after an occupational injury would be higher than that before an occupational injury was 3.17 (2.41–4.17) for those who returned to original work and 2.32 (1.81–2.97) for those re-employed as compared with who did not return to work and 1.27 (1.07–1.15) for those who retained their job as compared with those who did not. The ORs were 2.91 (2.26–3.75) for those who were re-employed and retained jobs and 2.96 (2.15–4.08) for those who returned to original work and did not retain jobs as compared with those who did not return to work and did not retain jobs.ConclusionsIt is important for accident victims to retain their jobs to maintain their economic status.

MDTF

The Equal slack (EQS) heuristic is one of the widely used priority assignment heuristics. However, it severely suffers from the problems of intensive data contention, deadlock, and cyclic restart. To overcome some of the above problems, this chapter proposes a Most Dependent Transaction First (MDTF) priority heuristic that injects the size of dependent transactions of all directly competing transactions (that have requested access to the conflicting data item) in their priority computation. The MDTF heuristic efficiently reduces the data contentions among concurrently executing cohorts; and thus, it reduces the wastage of the system resources. This dynamic cohort priority assignment heuristic reduces the data contention considerably by utilizing the information about the dependency size of cohort(s). Doing this will make it easy for a currently executing cohort to better assess the level of data contention with absolutely no extra communication and time overhead. Such detailed dependency information is very useful to efficiently assign priorities to the cohorts.