Horizons in Computer Science Research. Volume 18 first discusses intermittently connected networks, a form of the delay tolerant network, where there never exists a complete end-to-end path between two nodes wishing to communicate. The authors provide an overview of the current algorithms (both analytic and iterative) for the generation of tomographic images, including comparisons of the basic characteristics of image quality. An intelligent scheduling framework is proposed to alleviate the problems encountered in modern job scheduling. The challenges of high performance computing scheduling and state-of-art scheduling methods to overcome these challenges are investigated. The state of art developments in quantum cryptography are presented, as well as the fundamental laws of quantum physics that quantum key distribution is based on. Subsequently, three main protocols of key distribution are introduced which enable users to share a secret between them. Three iterative methods for dose reconstruction in protoacoustics are discussed, including: gradient-descent algorithm, SART and MLEM, which are widely used in other medical imaging modalities such as PET, SPECT and CT. Additionally, the authors evaluate the behaviour of the concurrent execution of tasks in different implementations by Java virtual machines. The performance measurements were analysed by rigorous statistical techniques: analysis of Variance and HSD comparison test of Tukey averages. A mathematical model for finding the distribution of threads in local pools that minimises the makespan in integration processes is also presented. Makespan is a metric that calculates the average time a message takes to be executed by an integration process. In closing, varied knowledge sources for aspect clustering are explored a new method, Op Cluster-PT, is proposed. To support this research, annotated corpora and some related resources that are publicly available to the interested reader have been included.