Evolutionary multitasking (EMT) is an emerging research topic in the field of evolutionary computation. In contrast to the traditional single-task evolutionary search, EMT conducts evolutionary search on multiple tasks simultaneously. It aims to improve convergence characteristics across multiple optimization problems at once by seamlessly transferring knowledge among them. Due to the efficacy of EMT, it has attracted lots of research attentions and several EMT algorithms have been proposed in the literature. However, existing EMT algorithms are usually based on a common mode of knowledge transfer in the form of implicit genetic transfer through chromosomal crossover. This mode cannot make use of multiple biases embedded in different evolutionary search operators, which could give better search performance when properly harnessed. Keeping this in mind, this paper proposes an EMT algorithm with explicit genetic transfer across tasks, namely EMT via autoencoding, which allows the incorporation of multiple search mechanisms with different biases in the EMT paradigm. To confirm the efficacy of the proposed EMT algorithm with explicit autoencoding, comprehensive empirical studies have been conducted on both the single- and multi-objective multitask optimization problems.

Long-term evolution (LTE) of the UMTS TerrestrialRadio Access and Radio Access Network is considered to ensure the competitiveness of 3GPP radio-access technology in a longer time frame. To minimize/optimize the user equipment (UE) power consumption, and further to support various services and large amount of data transmissions, a discontinuous reception (DRX) mechanism with adjustable DRX cycles has been adopted in LTE RRC_CONNECTED mode. In this paper, we take an overview of the DRX cycle adjustable feature of the LTE power saving mechanism and further modeling the mechanism with bursty packet data traffic using a semi-Markov process. The analytical results, which are validated against simulation experiments, show that LTE DRX achieves power saving gains over UMTS DRX at the price of prolonging wake-up delay. Based on the analytical model, effects of the DRX parameters on the power saving and wake-up delay performance are also investigated, and the results verify a trade-off relationship between the power saving and wake-up delay performance.

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