Evolving Robocode Tank Fighters

In this paper, I describe the application of genetic programming to evolve a controller for a robotic tank in a simulated environment. The purpose is to explore how genetic techniques can best be applied to produce controllers based on subsumption and behavior oriented languages such as REX. As part of my implementation, I developed TableRex, a modification of REX that can be expressed on a fixed-length genome. Using a fixed subsumption architecture of TableRex modules, I evolved robots that beat some of the most competitive hand-coded adversaries

Terrain Representation And Reasoning In Computer Generated Forces : A Survey Of Computer Generated Forces Systems And How They Represent And Reason About Terrain

Report on a survey of computer systems used to produce realistic or intelligent behavior by autonomous entities in simulation systems. In particular, it is concerned with the data structures used by computer generated forces systems to represent terrain and the algorithmic approaches used by those systems to reason about terrain

Safeguarding the Welfare of Fish in Aquaculture : Physiological Assessments of Stress and Welfare During Handling, Transport and Slaughter

The increased demand of fish for human consumption has led to a rapid expansion of aquaculture. However, there are major knowledge gaps regarding species-specific needs, which entails an increased risk that fish are exposed to various aquaculture practices that have negative effects on their welfare. The purpose of this thesis has been to gain knowledge that can be used to assess the welfare of fish in aquaculture. To do so I have investigated various physiological indicators of fish welfare during handling, transport, and slaughter. First, the long-term effect of implantation of a heart rate bio-logger in the rainbow trout (Oncorhynchus mykiss) was investigated. I found no indications of impaired health three weeks after surgery, and concluded that these individuals can be assumed to represent a healthy population. The same type of bio-logger was then used, in combination with other biochemical stress indicators, to investigate the effect of repeated stress from handling, transport and slaughter in European whitefish (Coregonus lavaretus). The results clearly showed that the animals were stressed during crowding and brailing prior to transportation and during subsequent stunning before killing. To evaluate the reliability of a range of practical visual indicators of unconsciousness, measurements of Electroencephalogram was used, where changes in brain activity of rainbow trout before and after stunning with carbon dioxide, bolt-gun and electricity were investigated. Unfortunately, the result showed that the practical visual indicators used to assess unconsciousness was in poor agreement with the assessment based on brain activity. In summary, several important findings are presented here that can be used to improve fish welfare in aquaculture, and which can form the basis for future regulations and general advice on how fish should be handled, kept, cared for, and stunned and killed

Exploring peripheral LOD change detections during interactive gaming tasks

Computer games require players to interact with scenes while performing various tasks. In this paper an experimental game framework was developed to measure players perception to level of detail (LOD) changes in 3D models (for example a bunny), as shown in Figure 1. These models were unrelated to the task assigned to the player and located away from the area in which the task was being accomplished. An interactive task, such as a point and shoot game, triggers a top-down vision process. Performing a specific task can result in inattentional blindness (IB) for the player, which is the phenomenon of not being able to perceive things that are in plain sight. IB can allow for substantial simplifications of the objects in the scene unrelated to the task at hand. In this paper five experiments were conducted exploring peripheral LOD change detections during an interactive gaming task. In three of the five experiments different level of awareness for the same task were tested and it was found that only participants being fully aware of the 3D LOD changes were able to detect about 15% of them during the game. In the other two experiments and with the players fully aware of the LOD changes, the distance at which they were able to detect each change of resolution was measured, with different number of LOD levels used in both experiments

Spinal injury in underbody blast

Improvised Explosive Device (IED) is common in insurgent conflict as such devices are cheap, available, and devastating. Recent literature shows that victims of these devices often have complex injuries including spinal fractures. However, spinal injuries are not described in detail, so the mechanism and effects of these injuries are not well understood. This thesis reviews the literature with respect to spinal injuries in blast and compares it to UK military victims of IED attacks with spinal fractures. In the UK population, the majority of spinal fractures are thoracolumbar and are associated with multiple other injuries. This thesis shows that, based on the patterns of injury in UK blast victims, most fractures are caused by a combination of axial loads and flexion, with the apex of the thoracic spine and the thoracolumbar junction most affected by flexion. Military vehicles incorporate features intended to reduce the effect of blast on their occupants, and a standardised test has been established to evaluate such designs. However, the simple model of the spine used for these tests lacks validity. Understanding the behaviour of the spine in blast incidents will support development of an improved injury prediction model for future vehicle design. In this thesis an in vitro study develops a model to understand the role of posture in shaping fracture patterns when the spine is loaded at the rates seen in blast, and supports the mechanistic propositions this thesis makes about the behaviour of the spine in underbody blast. The clinical outcome and functional effect of blast related spinal fractures is unknown. In a short case series, this thesis suggests that spinal fractures lead to significant pain but the effect of spinal injuries on function is unclear as these victims also have other severe injuries.Open Acces

CPU Resource Management and Noise Filtering for PID Control

The first part of the thesis deals with adaptive CPU resource management for multicore platforms. The work was done as a part of the resource manager component of the adaptive resource management framework implemented in the European ACTORS project. The framework dynamically allocates CPU resources for the applications. The key element of the framework is the resource manager that combines feedforward and feedback algorithms together with reservation techniques. The resource requirements of the applications are provided through service level tables. Dynamic bandwidth allocation is performed by the resource manager which adapts applications to changes in resource availability, and adapts the resource allocation to changes in application requirements. The dynamic bandwidth allocation allows to obtain real application models through the tuning and update of the initial service level tables. The second part of the thesis deals with the design of measurement noise filters for PID control. The design is based on an iterative approach to calculate the filter time constant, which requires the information in terms of an FOTD model of the process. Tuning methods such as Lambda, SIMC, and AMIGO are used to obtain the controller parameters. New criteria based on the trade-offs between performance, robustness, and attenuation of measurement noise are proposed for assessment of the design. Simple rules for calculating the filter time constant based on the nominal process model and the nominal controller are then derived, thus, eliminating the need for iteration. Finally, a complete tuning procedure is proposed. The tuning procedure accounts for the effects of filtering in the nominal process. Hence, the added dynamics are included in the filtered process model, which is then used to recalculate the controller tuning parameters

Ramifications of Projectile Velocity on the Ballistic Dart Penetration of Sand

With the advent of novel in-situ experimental measurement techniques, highly resolved quantitative observations of dynamic events within granular media can now be made. In particular, high speed imagery and digital analysis now allow for the ballistic behaviors of sand to be examined not only across a range of event velocities but across multiple length scales. In an attempt to further understand the dynamic behavior of granular media, these new experimental developments were implemented utilizing high speed photography coupled with piezo-electric stress gauges to observe visually accessible ballistic events of a dart penetrating Ottawa sand. Projectile velocities ranged from 100 to over 300 meters per second with two distinct chosen fields of view to capture bulk and grain-scale behaviors. Each event was analyzed using the digital image correlation technique, particle image velocimetry from which two dimensional, temporally resolved, velocity fields were extracted, from which bulk granular flow and compaction wave propagation were observed and quantified. By comparing bulk, in situ, velocity field behavior resultant from dart penetration, momentum transfer could be quantified measuring radius of influence or dilatant fluid approximations from which a positive correlation was found across the explored velocity regime, including self similar tendencies. This was, however, not absolute as persistent scatter was observed attributed to granular heterogeneous effects. These were tentatively measured in terms of an irreversible energy amount calculated via energy balance. Grain scale analysis reveals analogous behavior to the bulk response with more chaotic structure, though conclusions were limited by the image processing method to qualitative observations. Even so, critical granular behaviors could be seen, such as densification, pore collapse, and grain fracture from which basic heterogeneous phenomena could be examined. These particularly dominated near nose interactions at high projectile velocities. Resulting empirical models and observations from all approaches provide a baseline from which other studies across may be compared, a metric against which penetrator effectiveness may be evaluated, and an alternative way to validate computationally based analyses. Velocity analysis was further contrasted with piezo-resistive stress gauge data in an effort to pair heterogeneous mechanisms in the bulk stress response. Phenomena such as grain fracture and densification were successfully observed in conjunction with a unique stress signature. Comparing stress responses across the tested velocity spectrum confirm conditional similitude with deviations a low projectile velocities attributed to domination by heterogeneous mechanisms

Stormwater Disconnection: Transient Scenario Analysis of Intervention Flexibility

Urban drainage networks protect people, society, and the environment from the hazards presented by domestic and industrial effluent, and urban stormwater run-off. However, urban drainage networks are financially and carbon intensive, and their failure results in damage to people and the environment. The likelihood and magnitude of failure is anticipated to increase in the future as a result of pressures including climate change and urbanisation. The rate and extent of these pressures manifesting is uncertain. Sustainable drainage systems (SuDS) are structural measures that can be retrofitted to replace or augment an urban drainage network, reducing the likelihood of failure now and in the future. Adaptation of infrastructure to encroaching future pressures requires infrastructure constructed in the present to be flexible. An existing method for assessing flexibility is combined with transient scenario analysis to enable the flexibility of conventional solutions, and source-control and regional-control retrofit SuDS interventions to be compared in two real-world case-study catchments. A new multi-criteria assessment framework is proposed for the comparison of these interventions. A method for distributing retrofit SuDS within an urban drainage catchment is developed from first principles. It is a hydraulic modelling method based on identifying potentially disparate locations within an urban drainage catchment that possess similar times of concentration to a point of interest within the network. The concept of the efficiency of stormwater disconnection is introduced. The developed method is shown to be more effective at identifying efficient disconnection locations than existing methods in two real-world case study catchments