Evaluating a Prototype Approach to Validating a DDS-based System Architecture for Automated Manufacturing Environments

Data Distribution Services (DDS) are emerging as communication systems in manufacturing environments. One of the key features of a DDS based system is the ability to regain performance levels after the introduction or removal of a DDS participant. In implementing a DDS participant to an existing system, message transport speed and message latency is often sacrificed due to protection problems in OEM software. Validity and suitability for integration of OpenDDS specifically, a manufacturing system is evaluated by defining two implementation scenarios; a flexible approach with a dedicated DDS participant application, and a high speed approach integrating the OpenDDS API directly in the target application. The system is validated by monitoring performance, efficiency and robustness in use and implementation. This result is part of a system architecture, developed for project Smart Industrial Robotics (SInBot), that focuses on maximizing the efficient use of mobile industrial robots during medium sized production runs. This modular system architecture is based on distributed intelligence and decentralized control to enable online reconfiguration of industrial robots in manufacturing facilities

Multi-objective surrogate based hull-form optimization using high-fidelity rans computations

RANS-based optimization procedures for ship design become increasingly complex and require the development of more efficient optimization techniques. The four phases of the design procedure are: shape parameterization, global sensitivity analysis, multi-objective optimization and design review. The dimensions of the design space can be mitigated by a smart choice for the shape parameterization and by screening and ranking the design variables in the global sensitivity phase. Subsequently, Surrogate Based Global Optimization (SBGO) is used to reduce the cost of the multi-objective optimization phase. For a practical application it is shown that the computational time reduces from two weeks to only a day when using SBGO instead of applying a Multi-Objective Genetic Algorithm (MOGA) directly to the solver. The design review phase is then used to verify and further develop the optimal design. Here, we focus on automatic ship design techniques which comprises the first three steps of the design procedure. Accelerating the ship design process is subject of ongoing research at the Maritime Research Institute Netherlands, making it useful for practical applications with turnaround times of only a few weeks

Survey of herbicide-resistant wild oat (Avena fatua L.) in two townships in Saskatchewan

Non-Peer ReviewedThe objective of this study was to determine the nature and occurrence of herbicide resistance in wild oat in the Grassland and Parkland regions of Saskatchewan in 1997, based on a systematic survey of fields in two randomly selected townships. The survey found that: 1) over one-half of fields in both townships had populations resistant to Group 1, 2, and/or 8 herbicides; 2) fields in the Parkland township had higher mean levels of Group 1 resistance (% resistant seeds) than fields in the Grassland township, suggesting they were subjected to more Group-1 herbicide applications; and 3) single- (Groups 1, 2, or 8) and multiple-group resistance (1,2; 1,8; 2,8; 1,2,8) were exhibited in populations in fields in both townships. The proportion of fields with populations exhibiting Group 1 (single) resistance was higher, and Group 2 and Groups 1,2 resistance were lower in the Parkland compared to that in the Grassland township. In both townships, farmers with more land (within the township or total farmed) tended to have a greater proportion of that land infested with Group 1- or 2-resistant wild oat compared to those with less land. The nature of resistance in wild oat populations in Saskatchewan is more diverse, differences in distribution and abundance of resistant biotypes between Grassland and Parkland regions are generally less apparent, and occurrence of resistance is more prevalent than previously documented

The Prediction of Voting Behaviour in a Nuclear Energy Referendum

This report describes an application of Fishbein's model of intention formation to a study of voting choice in a nuclear energy ballot in the USA. The sample was randomly selected from the general public (N = 89). The model successfully predicted bvoting intention (multiple regression coefficient = .92) using two major variables: attitudes to the act of voting CON and subjective norms, i.e. the voter's perceptions of how the people or groups important to them (referents) would want them to vote. Both of these components contributed significantly to voting choice although the attitude was the primary determinant. The attitudes to the act of voting and the subjective norms were, in turn, well predicted from underlying beliefs, thus allowing identification of the specific issues which differentiated between those intending to vote PRO and CON on nuclear energy. In general both groups of voters agreed on their evaluations of the possible consequences of the ballot. Further, they were both well informed about the basic issues and potential legal consequences of the proposal. What ultimately appears to have influenced the direction of their vote was their disagreement (i.e. their contrary beliefs) about the likely effects of the proposal on three major issues: the economy, the energy crisis and improvements in nuclear safety. The positions taken on these issues clearly differentiated those intending to vote PRO and CON. It should be noted, however, that the other issues about which there was considerable debate, e.g. the question of the constitutional status of the proposal, did not significantly differentiate the two groups of voters

Nuclear Energy: The Accuracy of Policy Makers Perceptions of Public Beliefs

The primary purpose of this study was to empirically test how accurate a group of policy makers were in their assessment of the beliefs and attitudes of the public with regard to the use of nuclear energy. The respondents (n=40) were senior Austrian civil servants responsible for energy matters. The questionnaire used was the same as that employed earlier to measure the attitudes and underlying beliefs of the Austrian public (n=224) and the sub-groups (n=50) of this sample most PRO and CON the use of nuclear energy. The policy makers completed this questionnaire twice: once with respect to their own positions and, on the second occasion, in the role of a typical member of the Austrian public who was either PRO or CON the use of nuclear energy. This experimental design also permitted comparisons between the policy makers' own positions and those of the general public. Public attitudes toward the use of nuclear energy were found, using factor analysis, to be based upon four underlying dimensions of belief: psychological (anxiety-inducing) risks; economic/technical benefits; socio-political implications; and environmental/physical risks. The policy makers' own attitudes were found to be significantly more favourable than those of the total public sample; this was primarily because the policy makers' beliefs about psychological risks made a significantly smaller negative contribution to attitude, and their beliefs about environmental risks made a significantly larger positive contribution. The policy makers were able to shift their own (personal) responses in the directions indicated by their role-play assignments to accurately reproduce the overall attitudes of the PRO and CON groups on this controversial topic, although there was a tendency to overestimate the positive attitudes of the PRO nuclear public. In terms of the underlying belief dimensions however, there was a significant failure to recognise the extent to which issues of psychological significance contribute negatively to the attitudes of both PRO and CON public groups. The policy makers underestimated the negative value both groups assigned to these risks as well as the extent to which the public believed that nuclear energy would lead to such risks

Alberta field survey of herbicide-resistant weeds

Non-Peer ReviewedIn 2001, 236 fields were randomly selected throughout the ecoregions of Alberta and surveyed for grass and broadleaf weeds resistant to Group 1 (ACCase inhibitor) or Group 2 (ALS inhibitor) herbicides. Nearly 20% of surveyed fields had a herbicide-resistant weed biotype. Only 5% of producers with resistant biotypes were aware of their occurrence. This survey serves as a baseline for determining future trends in weed resistance in Alberta

Modelling a Dune Field

We present a model to describe the collective motion of barchan dunes in a field. Our model is able to reproduce the observation that a typical dune stays confined within a stripe. We also obtain some of the pattern structures which ressemble those observed from aerial photos which we do analyse and compare with the specific field of La\^ayounne.Comment: 15 pages, 13 figure

The transition between hole-pairs and four-hole clusters in four-leg tJ ladders

Holes weakly doped into a four-leg \tj ladder bind in pairs. At dopings exceeding a critical doping of $\delta_c\simeq {1/8}$ four hole clusters are observed to form in DMRG calculations. The symmetry of the ground state wavefunction does not change and we are able to reproduce this behavior qualitatively with an effective bosonic model in which the four-leg ladder is represented as two coupled two-leg ladders and hole-pairs are mapped on hard core bosons moving along and between these ladders. At lower dopings, $\delta<\delta_c$, a one dimensional bosonic representation for hole-pairs works and allows us to calculate accurately the Luttinger liquid parameter \krho, which takes the universal value \krho=1 as half-filling is approached