Operational research:methods and applications

Throughout its history, Operational Research has evolved to include a variety of methods, models and algorithms that have been applied to a diverse and wide range of contexts. This encyclopedic article consists of two main sections: methods and applications. The first aims to summarise the up-to-date knowledge and provide an overview of the state-of-the-art methods and key developments in the various subdomains of the field. The second offers a wide-ranging list of areas where Operational Research has been applied. The article is meant to be read in a nonlinear fashion. It should be used as a point of reference or first-port-of-call for a diverse pool of readers: academics, researchers, students, and practitioners. The entries within the methods and applications sections are presented in alphabetical order

Using MapReduce Streaming for Distributed Life Simulation on the Cloud

Distributed software simulations are indispensable in the study of large-scale life models but often require the use of technically complex lower-level distributed computing frameworks, such as MPI. We propose to overcome the complexity challenge by applying the emerging MapReduce (MR) model to distributed life simulations and by running such simulations on the cloud. Technically, we design optimized MR streaming algorithms for discrete and continuous versions of Conway’s life according to a general MR streaming pattern. We chose life because it is simple enough as a testbed for MR’s applicability to a-life simulations and general enough to make our results applicable to various lattice-based a-life models. We implement and empirically evaluate our algorithms’ performance on Amazon’s Elastic MR cloud. Our experiments demonstrate that a single MR optimization technique called strip partitioning can reduce the execution time of continuous life simulations by 64%. To the best of our knowledge, we are the first to propose and evaluate MR streaming algorithms for lattice-based simulations. Our algorithms can serve as prototypes in the development of novel MR simulation algorithms for large-scale lattice-based a-life models.https://digitalcommons.chapman.edu/scs_books/1014/thumbnail.jp

A Network-Based Design Synthesis of Distributed Ship Services Systems for a Non Nuclear Powered Submarine in Early Stage Design

Even though the early-stage design of a complex vessel is where the important decisions are made, the synthesis of the distributed ship service systems (DS3) often relies on “past practice” and simple vessel displacement based weight algorithms. Such an approach inhibits the ability of the concept designer to consider the impact of different DS3 options. It also reduces the ability to undertake Requirements Elucidation, especially regarding the DS3. Given the vital role the many DS3 provide to a submarine, this research considers whether there is a better way to synthesise DS3 without resorting to the detailed design of the distributed systems, which is usually inappropriate at the exploratory stages of design. The research proposes a new approach, termed the Network Block Approach (NBA), combining the advantages of the 3D physical based synthesis UCL Design Building Block (DBB) approach with the Virgina Tech Architectural Flow Optimisation (AFO) method, when applied to submarine DS3 design. Utilising a set of novel frameworks and the Paramarine CASD tool, the proposed approach also enabled the development of the submarine concept design at different levels of granularities, ranging from modelling individual spaces to various DS3 components and routings. The proposed approach also allowed the designer to balance the energy demands of various distributed systems, performing a steady-state flow simulation, and visualising the complexity of the submarine DS3 in a 3D multiplex network configuration. Such 3D based physical and network syntheses provide potential benefits in early-stage submarine DS3 design. The overall aim of proposing and demonstrating a novel integrated DS3 synthesis approach applicable to concept naval submarine design was achieved, although several issues and limitations emerged during both the development and the implementation of the approach. Through identification of the research limitations, areas for future work aimed at improving the proposal have been outlined