Population extremal optimisation for discrete multi-objective optimisation problems

The power to solve intractable optimisation problems is often found through population based evolutionary methods. These include, but are not limited to, genetic algorithms, particle swarm optimisation, differential evolution and ant colony optimisation. While showing much promise as an effective optimiser, extremal optimisation uses only a single solution in its canonical form – and there are no standard population mechanics. In this paper, two population models for extremal optimisation are proposed and applied to a multi-objective version of the generalised assignment problem. These models use novel intervention/interaction strategies as well as collective memory in order to allow individual population members to work together. Additionally, a general non-dominated local search algorithm is developed and tested. Overall, the results show that improved attainment surfaces can be produced using population based interactions over not using them. The new EO approach is also shown to be highly competitive with an implementation of NSGA-II.No Full Tex

A parallel implementation of ant colony optimization

Ant Colony Optimization is a relatively new class of meta-heuristic search techniques for optimization problems. As it is a population-based technique that examines numerous solution options at each step of the algorithm, there are a variety of parallelization opportunities. In this paper, several parallel decomposition strategies are examined. These techniques are applied to a specific problem, namely the travelling salesman problem, with encouraging speedup and efficiency results.Full Tex

An Introduction to Temporal Optimisation using a Water Management Problem

Optimisation problems usually take the form of having a single or multiple objectives with a set of constraints. The model itself concerns a single problem for which the best possible solution is sought. Problems are usually static in the sense that they do not consider changes over time in a cumulative manner. Dynamic optimisation problems to incorporate changes. However, these are memoryless in that the problem description changes and a new problem is solved - but with little reference to any previous information. In this paper, a temporally augmented version of a water management problem which allows farmers to plan over long time horizons is introduced. A climate change projection model is used to predict both rainfall and temperature for the Murrumbidgee Irrigation Area in Australia for up to 50 years into the future. Three representative decades are extracted from the climate change model to create the temporal data sets. The results confirm the utility of the temporal approach and show, for the case study area, that crops that can feasibly and sustainably be grown will be a lot fewer than the present day in the challenging water-reduced conditions of the future

Integrating continuous differential evolution with discrete local search for meander line RFID antenna design

The automated design of meander line RFID antennas is a discrete self-avoiding walk(SAW) problem for which efficiency is to be maximized while resonant frequency is to beminimized. This work presents a novel exploration of how discrete local search may beincorporated into a continuous solver such as differential evolution (DE). A prior DE algorithmfor this problem that incorporates an adaptive solution encoding and a bias favoringantennas with low resonant frequency is extended by the addition of the backbite localsearch operator and a variety of schemes for reintroducing modified designs into the DEpopulation. The algorithm is extremely competitive with an existing ACO approach and thetechnique is transferable to other SAW problems and other continuous solvers. The findingsindicate that careful reintegration of discrete local search results into the continuous populationis necessary for effective performance

Reducing Nursing Home Use Through Consumer-Directed Personal Care Services

Highlights findings on how the Cash and Counseling program, which allows Medicaid enrollees with personal care services to hire their own care workers, affected nursing facility use and expenditures as well as personal care and Medicaid costs in Arkansas

A multi-objective extremal optimisation approach applied to RFID antenna design

Extremal Optimisation (EO) is a recent nature-inspired meta-heuristic whose search method is especially suitable to solve combinatorial optimisation problems. This paper presents the implementation of a multi-objective version of EO to solve the real-world Radio Frequency IDentification (RFID) antenna design problem, which must maximise efficiency and minimise resonant frequency. The approach we take produces novel modified meander line antenna designs. Another important contribution of this work is the incorporation of an inseparable fitness evaluation technique to perform the fitness evaluation of the components of solutions. This is due to the use of the NEC evaluation suite, which works as a black box process. When the results are compared with those generated by previous implementations based on Ant Colony Optimisation (ACO) and Differential Evolution (DE), it is evident that our approach is able to obtain competitive results, especially in the generation of antennas with high efficiency. These results indicate that our approach is able to perform well on this problem; however, these results can still be improved, as demonstrated through a manual local search process.Full Tex

A Computational Comparison of Evolutionary Algorithms for Water Resource Planning for Agricultural and Environmental Purposes

The use of water resources for agricultural purposes, particularly in arid and semi-arid regions, is a matter of increasing concern across the world. Optimisation techniques can play an important role in improving the allocation of land to different crops, based on a utility function (such as net revenue) and the water resources needed to support these. Recent work proposed a model formulation for an agricultural region in the Murrumbidgee Irrigation Area of the Murray-Darling River basin in Australia, and found that the well-known NSGA-II technique could produce sensible crop mixes while preserving ground and surface water for environmental purposes. In the present study we apply Differential Evolution using two different solution representations, one of which explores the restricted space in which no land is left fallow. The results improve on those of the prior NSGA-II and demonstrate that a combination of solution representations allows Differential Evolution to more thoroughly explore the multiobjective space of profit versus environment

Weighing the anchor: Lotmanian perspectives on the Fighting Poland symbol

Simple symbols occupy a unique position within the semiosphere, constituting the symbolic core of culture with their ability to condense cultural memory into nimble, economic forms. This simplicity facilitates persistence, allowing these elementary symbols to recur diachronically, penetrating multiple layers of cultural strata to emerge and flourish in new contexts and variations. A novel example of a symbol which illustrates these attributes is Znak Polski Walczącej – the Fighting Poland symbol. Created in 1942 by the Polish Underground State as a propaganda tool, this straightforward monogram, consisting of interconnected letters P and W, became the official hallmark of Polish resistance and is now a controversial de facto national symbol. This article employs the symbol as a case study to explore two Lotmanian symbolic concepts: the vast semantic capacity of simple symbols, and their dual nature as invariable/variable entities. Born out of a utilitarian need for simplicity in Nazi-occupied Warsaw, the efficient form of the Fighting Poland symbol was a pragmatic matter of life or death. However, further examination of its simple design also reveals an underlying archaic depth. This article argues that the Fighting Poland symbol, metonymically known as the kotwica (‘anchor’) owing to its distinct shape, can also be viewed as an “emissary” from earlier cultural epochs, namely ante-Nicene Christianity, which made use of anchor symbology during an era of persecution and upheaval. Ultimately, this article provides a new semiotic perspective on a historically active yet understudied symbol with past and present relevance

DEVELOPMENT OF NORTHROP-GRUMMAN MARK VIIE TRAINING UNIT AND WIRELESS VIDEO SYSTEM FOR USE IN IMMERSIVE ENVIRONMENTS

A training unit has been developed that allows NVESD researchers to develop training simulations within virtual environments to enhance infantry skill and awareness. A ground station was developed to house a computer, power system, and video transmission system. This station will allow for a remote operator to wirelessly send a video/audio stream to the handset. The ground station also allows the use of external video and audio inputs to be sent using onboard converters. Different wireless frequencies were evaluated to determine the best for long-range transmission of content. A handset was developed from a carbon fiber prototype shell. The handset features a video receiver, display, power system, OSD system, and external video inputs. The user can view transmitted video and audio while obtaining real-time GPS feedback from the OSD. The alternate video input allows the handset to be used within the virtual environments developed at the University of Kentucky’s Center for Visualization for virtual environments. This thesis will present the research conducted in order to develop Mark VIIE training unit including the requirements for the project, the desired functionality, the NVESD provided equipment, the analysis of the prospective components, the design of custom fabricated parts, and the assembly and integration of the components into a complete system

Barriers and Contradictions in the Resettlement of Single Homeless People

Research in one local authority area suggests that a number of social policy difficulties and contradictions need to be resolved if single homeless people are to be resettled effectively. In particular, there are competing pressures on social housing providers, who are expected to meet the needs of socially excluded individuals while also creating sustainable communities and operating in a cost efficient manner. The government needs to clarify that meeting housing need is a priority for social landlords, and provide adequate funding for long-term support, if single homeless people are to find appropriate permanent accommodation