On applying the set covering model to reseeding

The Functional BIST approach is a rather new BIST technique based on exploiting embedded system functionality to generate deterministic test patterns during BIST. The approach takes advantages of two well-known testing techniques, the arithmetic BIST approach and the reseeding method. The main contribution of the present paper consists in formulating the problem of an optimal reseeding computation as an instance of the set covering problem. The proposed approach guarantees high flexibility, is applicable to different functional modules, and, in general, provides a more efficient test set encoding then previous techniques. In addition, the approach shorts the computation time and allows to better exploiting the tradeoff between area overhead and global test length as well as to deal with larger circuits

Avian Response to Post Wildland Fire Reseeding Treatments in Great Basin Shrubsteppe

We investigated the effects of different fire restoration treatments on five shrubsteppe bird species in the Great Basin of central Utah. Sagebrush communities and the associated avifauna are under particular threat due to changing fire regimes. Although fires are locally destructive, it is hypothesized that they improve habitat by increasing landscape-level heterogeneity. As long as fire follows a historic fire regime, the plant and animal communities can usually recover. However, fires can and often do burn outside of the normal regime. The Milford Flat Fire, which occurred in west-central Utah, was the largest wildfire recorded in the Great Basin. Considered catastrophic, concern existed that natural recovery of sagebrush and its avifauna would be unlikely. To prevent this, vegetation reseeding treatments were applied immediately post-fire. These treatments included two seed mix types, with or without a shrub component, and three mechanical applications, drill seeding, aerial seeding followed by chaining, and aerial seeding only. We surveyed the avian community in the different treatment types and in untreated areas within the fire using line transect distance sampling methods. Using a space for time substitution, we sampled nearby unburned areas as reference to represent pre-fire conditions. We hypothesized that the treatment areas would be more similar to the reference than the untreated areas, and that the treatments would all have similar effects. We found some effect on the presence and extirpation of the birds at the guild and overall bird level. We found no significant effect from the treatments on the five study species at the species level, and no effects on bird densities. The effects of the restoration treatments were overshadowed by the effect of the fire on changing the habitat, namely, the density of sagebrush. We saw a pattern of birds responding to the removal or survival of sagebrush and the treatments were insufficient in affecting a short term response

Embedding deterministic patterns in partial pseudo-exhaustive test

The topic of this thesis is related to testing of very large scale integration circuits. The thesis presents the idea of optimizing mixed-mode built-in self-test (BIST) scheme. Mixed-mode BIST consists of two phases. The first phase is pseudo-random testing or partial pseudo-exhaustive testing (P-PET). For the faults not detected by the first phase, deterministic test patterns are generated and applied in the second phase. Hence, the defect coverage of the first phase influences the number of patterns to be generated and stored. The advantages of P-PET in comparison with usual pseudo-random test are in obtaining higher fault coverage and reducing the number of deterministic patterns in the second phase of mixed-mode BIST. Test pattern generation for P-PET is achieved by selecting characteristic polynomials of multiple-polynomial linear feedback shift register (MP-LFSR). In this thesis, the mixed-mode BIST scheme with P-PET in the first phase is further improved in terms of the fault coverage of the first phase. This is achieved by optimization of polynomial selection of P-PET. In usual mixed-mode BIST, the set of undetected by the first phase faults is handled in the second phase by generating deterministic test patterns for them. The method in the thesis is based on consideration of these patterns during polynomial selection. In other words, we are embedding deterministic test patterns in P-PET. In order to solve the problem, the algorithm for the selection of characteristic polynomials covering the pre-generated patterns is developed. The advantages of the proposed approach in terms of the defect coverage and the number of faults left after the first phase are presented using contemporary industrial circuits. A comparison with usual pseudo-random testing is also performed. The results prove the benefits of P-PET with embedded test patterns in terms of the fault coverage, while maintaining comparable test length and time

Network Theoretic Analyses and Enhancements of Evolutionary Algorithms

Information in evolutionary algorithms is available at multiple levels; however most analyses focus on the individual level. This dissertation extracts useful information from networks and communities formed by examining interrelationships between individuals in the populations as they change with time. Network theoretic analyses are extremely useful in multiple fields and applications, e.g., biology (regulation of gene expression), organizational behavior (social networks), and intelligence data analysis (message traffic on the Internet). Evolving populations are represented as dynamic networks, and we show that changes in population characteristics can be recognized at the level of the networks representing successive generations, with implications for possible improvements in the evolutionary algorithm, e.g., in deciding when a population is prematurely converging, and when a reinitialization of the population may be beneficial to avoid computational effort, or to improve the probability of finding better points to examine. In this dissertation, we show that network theoretic analyses can be applied to study, analyze and improve the performance of evolutionary algorithms. We propose various approaches to study the dynamic behavior of evolutionary algorithms, each highlighting the benefits of studying community-level behaviors, using graph properties and metrics to analyze evolutionary algorithms, identifying imminent convergence, and identifying time points at which it would help to reseed a fraction of the population. Improvements to evolutionary algorithms result in alleviating the effects of premature convergence occurrences, and saving computational effort by reaching better solutions faster. We demonstrate that this new approach, using network science to analyze evolutionary algorithms, is advantageous for a variety of evolutionary algorithms, including Genetic Algorithms, Particle Swarm Optimization, and Learning Classifier Systems

Organic production in the hills and uplands (OF0319)

It is Government policy to provide a framework in which organic farming can develop, promoting more sustainable and environmentally sound systems of livestock production. Scientific information is required on the development, performance and limitations of organic systems, to facilitate informed decision-making and to aid policy formulation. Using the established organic unit at Redesdale, the overall objective of this project was to evaluate and demonstrate the long-term potential of organic livestock production in the hills and uplands. The experiment was a systems study sited on one discrete farm unit covering 518 ha. Approximately 400 ha had been put into conversion in 1991, so that the experimental period (2002 - 2005) represented years 9 to 12 years of full organic production. Approximately 600 Scottish Blackface ewes were involved in the study, in four self-replacing flocks. At the start of conversion, one original heft (Dargues Dipper) was split to form two sub-hefts of equal stock carrying capacity. One sub-heft (Organic Dipper) was converted to organic production, while the second (Conventional Dipper) continued to be managed conventionally. The two other hefts (Cairn and Burnhead) were both converted to organic production. Beef production was based on spring calving suckler cows, managed in three sub-herds - two a direct comparison of organic and conventionally managed Angus cross cows put to a continental sire; the third consisting of organically managed Angus cows put to an Angus sire. Grassland management was based on a modified ‘Two Pasture’ hill system, integrating native hill, improved hill and inbye land for beef and sheep production. On the native hill, detailed long-term monitoring of vegetation change showed that botanical composition was more affected by previous and current stocking levels, and events such as heather beetle infestation, than by organic and or conventional management. On improved hill land, the underlying trend was regression to rush pasture, leading to reduced productivity on both organic and conventionally managed areas. On the more intensively managed inbye fields, soil fertility levels were adequately maintained on the organic areas, which received only farmyard manure and slurries. Soil pH was more stable than on conventional fields, which received soluable nitrogen fertiliser. Organic inbye fields were sown predominately with short term leys, based on Italian ryegrass and Red or Alsike clover, to provide greater competition for weeds. Production levels were approximately 70% that of fertilised conventional fields. Self sufficiency in winter forage averaged 107% and 93% for the organic and conventional livestock (both sheep and cattle enterprises) respectively. Established infestations of docks production proved difficult to control. Historically, the greatest success was obtained where dock numbers were sufficiently low to enable the plants to be removed manually, or semi-mechanically using a tractor/digger. Data collected as an observation study suggested that for heavy infestations a fallow period and grazing by pigs could have good potential for dock control. Consistent with earlier the phases of the study, sheep production levels were higher in the conventionally managed sheep. Organically managed ewes were significantly lighter and had lower body condition scores at most stages of the production cycle. Average lamb rearing percentages over the three years of the study were 124, 108,108 and 111 for Conventional Dipper, Organic Dipper, Cairn and Burnhead flocks respectively. Average lamb weaning weights (kg) were 31.8, 29.5, 31.3 and 32.9 respectively. Of the total crop, 65% of Conventional Dipper lambs were sold finished at a mean liveweight of 38.1 kg, returning an average of £40.03 (£1.05/kg). The balance (35%) were ewe lambs retained within the flock or sold for breeding. Depending on the flock, the majority of the organic lamb crop (55%-61%) were sold after weaning as stores for further finishing, at a price of approximately £1.15 per kg liveweight. Store hill lambs performed well finishing on an organic lowland farm, returning typical carcass weights of 18.5 kg and a mean sale date of mid-March. An arrangement was entered into to spread the financial risk, sharing the feeders margin between the store lamb producer and lowland finisher. This could be a useful model for wider application, between different farmers or regions with complementary resources. Across all four flocks, the three year average for ewe and hogg mortality was less than 5%. Lamb mortality averaged less than 10%, which compares well with quoted industry figures of 15%-20%. Parasite burdens were low and anthelmintic input was limited to a few individual lambs. No adverse effects were recorded as a result of the long-term withdrawal of clostridial and pasteurella vaccination from one of the three organic flocks (Cairn). Lower levels of performance in the organic flocks could be a multi-component effect of reduced forage availability, lower veterinary inputs, higher levels of subclinical disease etc. However, the most likely factor was the difference in how the improved hill and inbye land was managed under an alternate grazing regime, which allows access by sheep to only half the area of improved hill in any given year. There was little difference in the physical performance of directly comparable organic and conventional sub-herds producing continental cross calves. Conception rates were consistently high, averaging 94%. Calf weaning weights (kg) averaged 292, 297 and 298 for conventional halfbred, organic halfbred and organic Angus sub-herds respectively. Prices achieved (p/kg live weight) for store prices cattle were 102, 127 and 133 respectively. Despite higher prices for organic cattle sold as stores, carcass data from animals sold finished indicated poorer conformation and higher levels of fatness in Angus sired calves. Gross returns were £683 and £648 for continental and Angus calves respectively, representing a difference of £0.10/kg carcass weight (£2.24 Vs £2.34). The main technical issue associated with the organic suckler herd was ensuring an adequate supply of conserved fodder for a 200-day winter. Disease challenges were low and the only veterinary treatment given on a herd basis was a single treatment for lice during the winter period. Average gross margins (£/ewe) before forage costs were £56, £44, £46 and £49 for Conventional Dipper, Organic Dipper, Cairn and Burnhead flocks respectively. Whole flock gross margins averaged £7635, £4609, £5561 and £4315. Lower performance in the organic flocks resulted from a combination of lower sheep numbers, reduced lambing percentages, and the sale of store rather than finished animals. Countryside Stewardship Scheme payments could potentially have increased gross margin in the Burnhead flock to £7915. Gross margins (£/cow), before forage costs, for rearing and finishing enterprises combined were £755, £636 and £527 for conventional halfbred, organic halfbred and organic Angus sub-herds respectively. Forage costs (£/adjusted hectare) averaged £11 and £21 for organic and conventional sub-units respectively. The biggest single contributor to gross margin was stocking rate, which for the organic unit as a whole, was 54% that of the conventional (1.3 LU/adjusted ha Vs 0.7 LU/adjusted ha). For sheep and cattle enterprises combined, gross margins per Livestock Unit (LU), including forage costs, were £451 and £479 for conventional and organic sub-units respectively. The organic unit as a whole returned a gross margin per adjusted hectare 44% less than the conventional (£590 Vs £335). It could be suggested that in reducing stocking rate in pursuit of environmental gain, and adjusting management for better parasite control, the organic system at Redesdale has had to carry a disproportionate financial burden. To offset these effects would require an improvement in output, for example retaining a greater proportion of organic animals for finishing, or entry into an agri-environmental scheme. The period of the study coincides with the last three years of subsidy payments based primarily on the numbers of livestock carried. Historically, stocking rates have been a prime determinant of profitability when measured on a per hectare basis. Under organic management it was not possible to support sheep numbers at previous levels and maintain the same level of individual performance. The advent of support based on Single Farm Payment, further devolves stocking rate from overall profitability. More farmers may be tempted to convert, given that the opportunity cost of conversion is reduced. Decisions will be driven more by the relative strength of the organic market, technical or attitudinal constraints such as feeding 100% organically produced diets, and relative impacts on overall fixed costs. The case for organic farming conferring environmental benefit is clearer in lowland situations than in the hills. In theory, the difference between organic and conventional systems should be less stark under less intensive production prevalent in the hills and uplands. As yet, little has been done to determine the extent to which organic and conventional farmers have adopted practices with positive or negative impact on biodiversity or the agri-environment. Much depends on the attitude of the individual landowner. From a survey conducted by ADAS in Wales, the greatest benefits tend to occur where an organic farm is also participating in another agri-environmental scheme. The extent to which organic, and evolving conventional, systems complement or conflict with cross compliance or Water Framework Directive requirements has yet to be determined. At Redesdale, long-term studies of vegetation change on the native hill, showed a continuing decline in heather cover at the higher stocking rates. Where stocking rates were reduced significantly to accommodate a more balanced organic system there were indications of a positive, albeit slow response in botanical composition. Key to this is the ability to manage moorland in a more proactive way, and to have cattle available to graze Molinia and Nardus. This complementary effect of cattle not only controls the competitive effects of these grassy species with heather, but as demonstrated in other research projects, also benefits sheep performance. If the economics of cattle production becomes very adverse organic farmers may be forced to reduce cattle numbers, which could make some sheep-dominated systems less sustainable. The results indicate that for many hill and upland units, converting to an organic system is not likely to be a matter of minimal changes to existing management. In particular, stocking rate and balance of sheep and cattle at the start of conversion will have a major impact on the management required to achieve acceptable levels of animal performance, financial performance, input reduction and environmental gain. Recommendations were made for further research in the following areas:- Current behaviours and management practices for organic and conventional farmers; the interface of organic farming practice, and that of other agri-environmental schemes; environmental impact at the whole farm, or aggregated farm level; practices to enhance environmental benefit which can be used more widely on organic farms; control of weeds (rushes, thistles, bracken and docks); tightening regulations on non-organic feed allowances; internal and external parasite control; nutrient budgeting; wider cropping options for energy, protein and mineral nutrition; the potential to exploit co-operative effort to overcome technical issues and limitations, and increase environmental benefit

Bridging Post-Wildfire Communication Gaps between Managers, Researchers, and Local Communities, including a Biological Soil Crust Case Study

Following a wildfire, land management agencies act quickly to protect ecosystem services. We don\u27t currently understand how post-wildfire managers make trade-off decisions in these tight timelines, or if these decisions reflect current science. Using Brunson’s (2014) social-ecological systems multi-scalar model, surveys assessed manager opinions about post-wildfire projects, perceptions of stakeholder opinions, and ability or willingness to consider new science results. Public surveys asked local citizens their opinions about post-wildfire projects. Manager perceptions were measured through semi-structured phone interviews (n = 8) and a structured online survey (n = 256). Public surveys were mailed to 1,000 (971 deliverable, n = 152 usable) residents in rural and urban Great Basin and Mojave Desert ZIP codes. We found coarse- and fine-scale social and political opinions were associated with all post-wildfire management decisions, often creating perceived barriers to project implementation. Conversely, local citizens were more supportive of projects than managers perceived them to be. While the majority of managers and citizens supported the concept of incorporating experimental research, managers were less able to consider more specific research incorporation into actual projects. Ecologically, biological soil crusts (BSC) are emerging as an important fine-scale component of semi-arid restorations. However, even when BSCs are assessed prior to a restoration plan, it is unclear how or if this knowledge has any impact. BSCs were evaluated both socially and ecologically: all manager surveys contained questions specifically related to BSC, and a pilot greenhouse study assessed a) if seed drilling simulations on different stages of BSC may affect restoration plant establishment and b) if BSC excluded the invasive species Bromus tectorum. Similar to other new science results, managers were unlikely to be able/willing to consider BSC status in post-wildfire projects. However, our results suggest the possibility that, even when lightly burned, seeding strategy may influence native plant establishment. In ideal greenhouse conditions, B. tectorum was able to establish readily on both burned and unburned BSC

Nile Basin livestock water productivity

PN37 (Increasing Water-Use Efficiency for Food Production through Better Livestock Management - The Nile River Basin) set out to improve food security, reduce poverty and enhance agroecosystem health by managing livestock for more effective overall use of water. PN37 responded to water challenges posed by the CPWF, to the Nile Basin Initiative’s goal of better sharing benefits of water use, and to global need for the livestock sector to use agricultural water more efficiently and effectively. PN37 identified opportunities to increase livestock water productivity (LWP) in key production systems of Ethiopia, Sudan and Uganda. In all countries and systems, the research revealed important opportunities to increase LWP through site-specific sets of interventions including improved feed sourcing, enhanced animal production, water conservation, and strategic provisioning of drinking water. It concludes that better integration of livestock, crop, water, and land management can sustainably enhance livelihoods of many poor people throughout the Nile Basin and beyond that across much of sub-Saharan Africa