Time-sensitive networking (TSN) is an emerging technology widely used in real-time systems for its high bandwidth and deterministic timing properties. To ensure the deterministic transmission of Time-triggered (TT) messages, a guard band mechanism is employed to prevent interference from other messages, such as Audio-Video Bridging (AVB) and Best-effort (BE) messages, before transmitting the TT messages in TSN. However, this mechanism introduces transmission delays for non-TT messages and bandwidth wastes for the physical links. Another challenge arises from the default First-in-first-out (FIFO) order of incoming messages, resulting in a relatively low acceptance rate for non-TT messages. To address these issues, a hybrid scheduling algorithm based on the min-heap structure (HSMH) is proposed. For AVB messages, HSMH sorts them in ascending style on the basis of deadlines, guaranteeing the earliest deadline message to be sent first. For BE messages, a threshold is designed to diverge them into two queues: a FIFO queue and a STF (shortest-time-first) queue. The former outputs the messages in a FIFO style, while the latter outputs messages in a STF style. All the output order of AVB messages and STF-queue messages are arranged in a min-heap structure. The algorithm can efficiently improve the transmission rate of AVB messages, the sending rate of BE messages, and the overall link utilization. Experimental results demonstrate that the proposed algorithm outperforms existing approaches in all these three aspects.

This paper introduces a novel Real Relative encoding Genetic Algorithm (R$^{2}$GA) to tackle the workflow scheduling problem in heterogeneous distributed computing systems (HDCS). R$^{2}$GA employs a unique encoding mechanism, using real numbers to represent the relative positions of tasks in the schedulable task set. Decoding is performed by interpreting these real numbers in relation to the directed acyclic graph (DAG) of the workflow. This approach ensures that any sequence of randomly generated real numbers, produced by cross-over and mutation operations, can always be decoded into a valid solution, as the precedence constraints between tasks are explicitly defined by the DAG. The proposed encoding and decoding mechanism simplifies genetic operations and facilitates efficient exploration of the solution space. This inherent flexibility also allows R$^{2}$GA to be easily adapted to various optimization scenarios in workflow scheduling within HDCS. Additionally, R$^{2}$GA overcomes several issues associated with traditional genetic algorithms (GAs) and existing real-number encoding GAs, such as the generation of chromosomes that violate task precedence constraints and the strict limitations on gene value ranges. Experimental results show that R$^{2}$GA consistently delivers superior performance in terms of solution quality and efficiency compared to existing techniques.

Integrated Mapping and Scheduling (IMS) problems can be found in many domains, such as electronic design automation (EDA) and modern manufacturing systems. Optimization algorithms to solve the IMS problems can be used to minimize execution time, implementation cost, energy consumption, etc. Genetic Algorithms (GAs) are powerful evolutionary algorithms for tackling many of such IMS op-timization problems. By utilizing biological principles like selection, crossover, and mutation, GAs excel in generating high-quality solutions. Chromosome encoding and decoding, in addition to evolutionary operators, significantly influence GA's efficiency. This paper introduces a relative-priority genetic algorithm (RPGA), a novel GA for IMS problems, such as those in EDA. RPGA employs a unique encoding scheme tailored for IMS problems, especially those with OR nodes representing alternative operation paths. It encodes the relative priority of an operation in a chromosome, which can be divided into two parts: one for path selections and the other for operation scheduling and mappings. Efficient decoding of every chromosome into a solution is facilitated through the concept of a ready operation set. The study extensively compares RPGA and established meta-heuristics using a benchmark set. The experimental results demonstrate that RPGA achieves high solution quality and rapid convergence.