A tractable analytical model for large-scale congested protein synthesis networks

This paper presents an analytical model, based on finite capacity queueing network theory, to evaluate congestion in protein synthesis networks. These networks are modeled as a set of single server bufferless queues in a tandem topology. This model proposes a detailed state space formulation, which provides a fine description of congestion and contributes to a better understanding of how the protein synthesis rate is deteriorated. The model approximates the marginal stationary distributions of each queue. It consists of a system of linear and quadratic equations that can be decoupled. The numerical performance of this method is evaluated for networks with up to 100,000 queues, considering scenarios with various levels of congestion. It is a computationally efficient and scalable method that is suitable to evaluate congestion for large-scale networks. Additionally, this paper generalizes the concept of blocking: blocking events can be triggered by an arbitrary set of queues. This generalization allows for a variety of blocking phenomena to be modeled.Swiss National Science Foundation (Grant 205320-117581

Analyzing and Optimizing Pedestrian Flow through a Single Route in a Topological Network

In emergency cases, people are typically recommended to use the shortest route to minimize their travelling time. This recommendation may however not yield the optimal performance in the long run since the route may be over utilized after a certain point of time and this situation eventually causes heavy blockages. This paper thus measures the pedestrian flow performance through all available single routes in a topological network based on relevant arrival rates. The performance was measured using an M/G/C/C state dependent queuing approach which dynamically models pedestrians’ walking speed in relation to their current density in a route. The analysis was based on an imaginary network consisting of various routes and topologies. For each route, its performance in terms of the throughput, blocking probability, expected number of pedestrians and expected travel time was first evaluated. The performance was then compared to each other and also compared to the flow performance if all available routes were utilized. The results indicated that the shortest route did not necessarily generate the optimal throughput and that the utilization of all available routes to flow pedestrians generated better performance. The optimal performance could be obtained if the arrival rate was controlled at a certain level

Throughput Maximization of Queueing Networks with Simultaneous Minimization of Service Rates and Buffers

The throughput of an acyclic, general-service time queueing network was optimized, and the total number of buffers and the overall service rate was reduced. To satisfy these conflicting objectives, a multiobjective genetic algorithm was developed and employed. Thus, our method produced a set of efficient solutions for more than one objective in the objective function. A comprehensive set of computational experiments was conducted to determine the efficacy and efficiency of the proposed approach. Interesting insights obtained from the analysis of a complex network may assist practitioners in planning general-service queueing networks

A tractable analytical model for large-scale congested protein synthesis networks

This paper presents a finite capacity queueing network model to evaluate congestion in protein synthesis networks. These networks are modeled as single server bufferless queues in a tandem topology. The model approximates the marginal stationary distributions of each queue. It consists of a system of linear and quadratic equations that can be decoupled. It is therefore a tractable and scalable method that is suitable for large-scale networks. This model proposes a detailed state space formulation, which provides a fine description of congestion and contributes to a better understanding of how the protein synthesis rate is deteriorated. This paper also generalizes the concept of blocking: blocking events can be triggered by an arbitrary set of queues. The numerical performance of this method is evaluated for networks with up to 100,000 queues, considering scenarios with various levels of congestion. Since tandem topology networks are of interest for a variety of application fields, the numerical efficiency and scalability of this model is of wide interest