4,157 research outputs found

    Interference Spins: Scheduling of Multiple Interfering Two-Way Wireless Links

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    Two-way is a dominant mode of communication in wireless systems. Departing from the tradition to optimize each transmission direction separately, recent work has demonstrated that, for time-division duplex (TDD) systems, optimizing the schedule of the two transmission directions depending on traffic load and interference condition leads to performance gains. In this letter, a general network of multiple interfering two-way links is studied under the assumption of a balanced load in the two directions for each link. Using the notion of interference spin, we introduce an algebraic framework for the optimization of two-way scheduling, along with an efficient optimization algorithm that is based on the pruning of a properly defined topology graph and dynamic programming. Numerical results demonstrate multi-fold rate gains with respect to baseline solutions, especially for worst-case (5%-ile) rates.Comment: Accepted for publication in IEEE Communications Letter

    Do nutrient uptakes and grain yields differ between spring barley varieties grown for organic farming as mono-crop and in mixture: Characteristics of spring barley varieties for organic farming

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    Manure application increased yield. Hence the study was conducted under the conditions of moderate nutrient stress and in all probability nitrogen stress. Under this condition nutrient uptakes, biomass production and grain yields did vary between Otira, Orthega, Landora, Brazil, Svani, NK96-300, Mixture 1 (Otira, Orthega, Landora) and Mixture 2 (Brazil, Svani and NK96-300). Interaction between variety and soil fertility treatments were also significant. These findings open new possibilities for selection or plant breeding for genotypes with improved capability of nutrient acquisition from soils at different soil fertility levels e.g. in organic farming. Cropping of barley varieties in mixtures seems to increase (stimulate) nutrient uptakes (N, P, S, K, Mg, Ca, Mn, Zn, Cu and Mo) and biomass production

    Automated software quality visualisation using fuzzy logic techniques

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    In the past decade there has been a concerted effort by the software industry to improve the quality of its products. This has led to the inception of various techniques with which to control and measure the process involved in software development. Methods like the Capability Maturity Model have introduced processes and strategies that require measurement in the form of software metrics. With the ever increasing number of software metrics being introduced by capability based processes, software development organisations are finding it more difficult to understand and interpret metric scores. This is particularly problematic for senior management and project managers where analysis of the actual data is not feasible. This paper proposes a method with which to visually represent metric scores so that managers can easily see how their organisation is performing relative to quality goals set for each type of metric. Acting primarily as a proof of concept and prototype, we suggest ways in which real customer needs can be translated into a feasible technical solution. The solution itself visualises metric scores in the form of a tree structure and utilises Fuzzy Logic techniques, XGMML, Web Services and the .NET Framework. Future work is proposed to extend the system from the prototype stage and to overcome a problem with the masking of poor scores

    Belief in public efficacy, trust and attitudes to modern genetic science

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    The official published version can be accessed from the links below - Copyright @ 2007 Wiley-BlackwellGovernment and policymakers want to engage the public in a dialogue about the conduct and consequences of science and increasingly seek to actively involve citizens in decision-making processes. Implicit in this thinking is that greater transparency and public inclusion will help dispel fears associated with new scientific advancements, foster greater public trust in those accountable, and ultimately increase the acceptability of new technologies. Less understood, however, are public perceptions about such high-level involvement in science and how these map onto public trust and attitudes within a diverse population. This article uses the concept of public efficacy—the extent to which people believe that the public might be able to affect the course of decision making—to explore differences in trust, attentiveness, and attitudes toward modern genetic science. Using nationally representative data from the 2003 British Social Attitudes Survey, we begin by examining the characteristics of those who have a positive belief about public involvement in this area of scientific inquiry. We then focus on how this belief maps on to indicators of public trust in key stakeholder groups, including the government and genetic scientists. Finally, we consider the relationship between public efficacy and trust and attitudes toward different applications of genetic technology. Our findings run contrary to assumptions that public involvement in science will foster greater trust and lead to a climate of greater acceptance for genetic technology. A belief in public efficacy does not uniformly equate with more trusting attitudes toward stakeholders but is associated with less trust in government rules. Whereas trust is positively correlated with more permissive attitudes about technologies such as cloning and gene therapy, people who believe in high-level public involvement are less likely to think that these technologies should be allowed than those who do not.The support of the Economics and Social Research Council (ESRC) is acknowledged. The work arises from the ESRC Attitudes to Genomics project L145251005

    Performance Analysis of MIMO-MRC in Double-Correlated Rayleigh Environments

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    We consider multiple-input multiple-output (MIMO) transmit beamforming systems with maximum ratio combining (MRC) receivers. The operating environment is Rayleigh-fading with both transmit and receive spatial correlation. We present exact expressions for the probability density function (p.d.f.) of the output signal-to-noise ratio (SNR), as well as the system outage probability. The results are based on explicit closed-form expressions which we derive for the p.d.f. and c.d.f. of the maximum eigenvalue of double-correlated complex Wishart matrices. For systems with two antennas at either the transmitter or the receiver, we also derive exact closed-form expressions for the symbol error rate (SER). The new expressions are used to prove that MIMO-MRC achieves the maximum available spatial diversity order, and to demonstrate the effect of spatial correlation. The analysis is validated through comparison with Monte-Carlo simulations.Comment: 25 pages. Submitted to the IEEE Transactions on Communication

    The DAWN Project evaluation 2007

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    Data management of on-line partial discharge monitoring using wireless sensor nodes integrated with a multi-agent system

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    On-line partial discharge monitoring has been the subject of significant research in previous years but little work has been carried out with regard to the management of on-site data. To date, on-line partial discharge monitoring within a substation has only been concerned with single plant items, so the data management problem has been minimal. As the age of plant equipment increases, so does the need for condition monitoring to ensure maximum lifespan. This paper presents an approach to the management of partial discharge data through the use of embedded monitoring techniques running on wireless sensor nodes. This method is illustrated by a case study on partial discharge monitoring data from an ageing HVDC reactor

    Depositional Environment, Reservoir Properties, and EOR Potential of an Incised-valley-fill Sandstone, Pleasant Prairie Oilfield, Haskell County, Kansas

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    Incised-valley-fill deposits form important hydrocarbon reservoirs and can have internal heterogeneities that affect recovery of hydrocarbon resources. Better understanding of the internal heterogeneity of incised-valley-fill reservoirs will help in more accurate reservoir modeling and more efficient recovery of hydrocarbon resources. Pleasant Prairie oilfield in Haskell County, Kansas, produces oil from an incised-valley-fill reservoir in the Chesterian (Upper Mississippian) Shore Airport Formation. The reservoir is part of a larger paleovalley trend interpreted as a tide-dominated, estuarine depositional system; depositional environments within such systems vary spatially as a result of interactions of tidal and fluvial processes. Core analysis suggests that the reservoir at Pleasant Prairie oilfield is a stacked series of conglomerate-based, fining-upward siliciclastic successions deposited in the river-dominated part of a tide-influenced estuarine system. Core petrophysical data and well-log correlations suggest that reservoir heterogeneity occurs in the form of vertical and lateral compartmentalization. Reservoir modeling indicates a current field-wide recovery factor of 0.30&ndash-&ndash 0.36 of original oil in place. Comparison of modeled original oil in place to production data suggests inaccuracy of reservoir models at the scale of individual well drainage areas. Waterflooding of the reservoir has proven successful for >10 years, and remaining oil in place ranges from 7.8&ndash-&ndash 10.1 mmbo according to Petrel10 years, and remaining oil in place ranges from 7.8&ndash-&ndash 10.1 mmbo according to PetrelTM models, indicating potential for future enhanced oil recovery operations such as CO2 or chemical flooding. Other incised-valley-fill reservoirs, such as Morrowan (Lower Pennsylvanian) oilfields in Colorado and Kansas, originated in similar depositional settings and display similar reservoir properties; such reservoirs may also have potential for future enhanced oil recovery operations

    New in-field treatment solutions to control Fruit Fly (1)

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    In-field management of fruit flies in fruiting vegetable crops has relied heavily on regular cover sprays with dimethoate and fenthion. However, recent restrictions in their use, and the possibility of further future restrictions, mean that alternative control options are required. The project aimed to assess a combination of perimeter protein baiting and male annihilation, and alternative chemical options, as well as obtaining data on seasonal fruit fly activity in vegetables. Semi-field trials were performed to assess eight insecticides, applied as cover sprays to fruiting capsicum and zucchini plants, for efficacy against Queensland fruit fly, Bactrocera tryoni, and cucumber fly, Zeugodacus cucumis. Clothianidin was very effective against Queensland fruit fly and cucumber fly. Thiacloprid, imidacloprid, cyantraniliprole and alphacypermethrin were also very effective against Queensland fruit fly, but less so against cucumber fly. Bifenthrin, spinetoram and abamectin demonstrated a suppressive effect. Alpha-cypermethrin, bifenthrin and dimethoate were linked to higher incidence of aphid and silverleaf whitefly infestation. A laboratory trial, in which Queensland fruit fly were exposed to dried insecticide residues on capsicum fruit, found that efficacy of thiacloprid was comparable with dimethoate, and spinetoram had a suppressive effect. Chlorantraniliprole and flubendiamide were ineffective. A trial was performed in a commercial chilli crop in Bundaberg to assess a combination of perimeter protein baiting and male annihilation for management of fruit fly. Sampling of fruit from the trial block throughout harvest found that the treatments successfully prevented infestation: no fruit fly larvae were found in any sampled fruit (a total 6966 fruit, 91 kg), with an upper infestation level of 0.04% (95% confidence). For comparison, sampling was also conducted in a second block, where regular cover sprays with dimethoate, trichlorfon and methomyl were applied. Seven flies were found in fruit sampled from the comparison block (3048 fruit, 49 kg), with an upper infestation level of 0.21% (95% confidence). The trial was repeated on a smaller scale in a research planting of capsicums at Bundaberg Research Facility, using a combination of perimeter protein baiting, male annihilation, and fortnightly cover sprays with spinetoram. A total of 12,995 fruit (2488 kg) were sampled. No larvae were recovered during winter, when fruit fly activity was low; however the control measures were not sufficient to prevent infestation outside of this period. The high local fruit fly pressure at the trial site coupled with the smaller size of the area over which control measures were applied were most likely critical factors. Monitoring was performed to obtain more information on the seasonal activity of fruit flies in vegetable crops in the Bundaberg region. Peak trap catch occurred in the spring, with a second peak in the summer. Monitoring also indicated an edge effect, with more flies caught in traps located along a tree-line, or within the crop close to the treeline, compared with those further within the crop. A trial targeting cucumber fly, using traps baited with a cucumber volatile lure, found that the BioTrap (BioTrap Australia Pty Ltd) was a better performing trap type for this species, catching an average of 9.1 cucumber flies per trap per day, compared with 0.7 cucumber flies per trap per day caught by Bugs for Bugs traps (Bugs for Bugs Pty Ltd). The average sex ratio of trapped flies was 74:26 female:male. However, further trials performed in the Fassifern Valley failed to catch cucumber flies

    New in-field treatment solutions to control Fruit Fly (1)

    Get PDF
    In-field management of fruit flies in fruiting vegetable crops has relied heavily on regular cover sprays with dimethoate and fenthion. However, recent restrictions in their use, and the possibility of further future restrictions, mean that alternative control options are required. The project aimed to assess a combination of perimeter protein baiting and male annihilation, and alternative chemical options, as well as obtaining data on seasonal fruit fly activity in vegetables. Semi-field trials were performed to assess eight insecticides, applied as cover sprays to fruiting capsicum and zucchini plants, for efficacy against Queensland fruit fly, Bactrocera tryoni, and cucumber fly, Zeugodacus cucumis. Clothianidin was very effective against Queensland fruit fly and cucumber fly. Thiacloprid, imidacloprid, cyantraniliprole and alphacypermethrin were also very effective against Queensland fruit fly, but less so against cucumber fly. Bifenthrin, spinetoram and abamectin demonstrated a suppressive effect. Alpha-cypermethrin, bifenthrin and dimethoate were linked to higher incidence of aphid and silverleaf whitefly infestation. A laboratory trial, in which Queensland fruit fly were exposed to dried insecticide residues on capsicum fruit, found that efficacy of thiacloprid was comparable with dimethoate, and spinetoram had a suppressive effect. Chlorantraniliprole and flubendiamide were ineffective. A trial was performed in a commercial chilli crop in Bundaberg to assess a combination of perimeter protein baiting and male annihilation for management of fruit fly. Sampling of fruit from the trial block throughout harvest found that the treatments successfully prevented infestation: no fruit fly larvae were found in any sampled fruit (a total 6966 fruit, 91 kg), with an upper infestation level of 0.04% (95% confidence). For comparison, sampling was also conducted in a second block, where regular cover sprays with dimethoate, trichlorfon and methomyl were applied. Seven flies were found in fruit sampled from the comparison block (3048 fruit, 49 kg), with an upper infestation level of 0.21% (95% confidence). The trial was repeated on a smaller scale in a research planting of capsicums at Bundaberg Research Facility, using a combination of perimeter protein baiting, male annihilation, and fortnightly cover sprays with spinetoram. A total of 12,995 fruit (2488 kg) were sampled. No larvae were recovered during winter, when fruit fly activity was low; however the control measures were not sufficient to prevent infestation outside of this period. The high local fruit fly pressure at the trial site coupled with the smaller size of the area over which control measures were applied were most likely critical factors. Monitoring was performed to obtain more information on the seasonal activity of fruit flies in vegetable crops in the Bundaberg region. Peak trap catch occurred in the spring, with a second peak in the summer. Monitoring also indicated an edge effect, with more flies caught in traps located along a tree-line, or within the crop close to the treeline, compared with those further within the crop. A trial targeting cucumber fly, using traps baited with a cucumber volatile lure, found that the BioTrap (BioTrap Australia Pty Ltd) was a better performing trap type for this species, catching an average of 9.1 cucumber flies per trap per day, compared with 0.7 cucumber flies per trap per day caught by Bugs for Bugs traps (Bugs for Bugs Pty Ltd). The average sex ratio of trapped flies was 74:26 female:male. However, further trials performed in the Fassifern Valley failed to catch cucumber flies
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