Adaptive equalisation for fading digital communication channels

This thesis considers the design of new adaptive equalisers for fading digital communication channels. The role of equalisation is discussed in the context of the functions of a digital radio communication system and both conventional and more recent novel equaliser designs are described. The application of recurrent neural networks to the problem of equalisation is developed from a theoretical study of a single node structure to the design of multinode structures. These neural networks are shown to cancel intersymbol interference in a manner mimicking conventional techniques and simulations demonstrate their sensitivity to symbol estimation errors. In addition the error mechanisms of conventional maximum likelihood equalisers operating on rapidly time-varying channels are investigated and highlight the problems of channel estimation using delayed and often incorrect symbol estimates. The relative sensitivity of Bayesian equalisation techniques to errors in the channel estimate is studied and demonstrates that the structure's equalisation capability is also susceptible to such errors. Applications of multiple channel estimator methods are developed, leading to reduced complexity structures which trade performance for a smaller computational load. These novel structures are shown to provide an improvement over the conventional techniques, especially for rapidly time-varying channels, by reducing the time delay in the channel estimation process. Finally, the use of confidence measures of the equaliser's symbol estimates in order to improve channel estimation is studied and isolates the critical areas in the development of the technique — the production of reliable confidence measures by the equalisers and the statistics of symbol estimation error bursts

Avian Survey Methods for Use at Airports

Adverse effects and damage caused by interactions between humans and wildlife are increasing (DeStephana and DeGraaf 2003). To manage wildlife effectively- whether to mitigate damage. to enhance safety, or to reach conservation goals-wildlife biologists must identify hazards posed by or to members of a particular species (i.e., a population) or guild, and then prioritize management goals and specific actions. We examine the special problem of managing birds to reduce hazards to aviation, particularly those species known to cause structural damage to aircraft when struck and that ·pose problems to airport facilities (Dolbeer et al. 2000, Cleary and Dolbeer 2005, DeVault et al. 2011). Effective management of hazardous species at airports requires knowledge of species abundance and how abundance varies over time. In this context, the quality of the sampling methodology used will influence a biologist\u27s ability to accurately quantify avian hazards and to understand the ecological interactions of populations or guilds using airport environments

Avian Survey Methods for Use on Airports

Management of wildlife, whether to mitigate damage, enhance safety, or effect conservation goals, requires identification of hazards posed by or to members of a particular species population or guild, and prioritization of management goals. We examined the special problem of managing birds to reduce hazards to aviation, particularly those species known to cause structural damage to aircraft when struck, as well as posing problems to airport facilities. Our objectives were to synthesize sampling theory and methods to provide airport biologists with 1) means to design and implement an avian survey on an airport that will maximize accuracy in quantifying avian hazards; 2) an understanding of bias and precision, and their influences on quantification of avian hazards; 3) suggestions on how to quantify avian hazards and use these data to estimate relative risk posed to aviation safety by a particular species or guild by time period and habitat type; and 4) knowledge of how data can be used to prioritize management goals. Our recommendations are intended to compliment U.S. Federal Aviation Administration procedures for Wildlife Hazard Assessments and subsequent management on airports. We stress the need for survey data to be ecologically relevant and accurate, such that management guidelines are defensible. However, we recognize that “real world” issues, such as regulatory, labor, and financial constraints, as well as the dynamics of airport environments, inevitably influence survey methods. Though we do not advocate use of naive count data in estimating relative abundance or habitat use, we recognize that animal observations obtained by airport biologists outside of a standardized sampling protocol are critical for identifying potential hazards to aviation safety. We recommend field testing of our suggestions and development of training materials for airport biologists that distill the information that we will present in light of constraints affecting survey design and conduct

「環太平洋の言語」日本班

初巻は別書誌『消滅に瀕した方言アクセントの緊急調査研究

Evolutionary response to global change: Climate and land use interact to shape color polymorphism in a woodland salamander

Evolutionary change has been demonstrated to occur rapidly in human‐modified systems, yet understanding how multiple components of global change interact to affect adaptive evolution remains a critical knowledge gap. Climate change is predicted to impose directional selection on traits to reduce thermal stress, but the strength of directional selection may be mediated by changes in the thermal environment driven by land use. We examined how regional climatic conditions and land use interact to affect genetically based color polymorphism in the eastern red‐backed salamander (Plethodon cinereus). P. cinereus is a woodland salamander with two primary discrete color morphs (striped, unstriped) that have been associated with macroclimatic conditions. Striped individuals are most common in colder regions, but morph frequencies can be variable within climate zones. We used path analysis to analyze morph frequencies among 238,591 individual salamanders across 1,170 sites in North America. Frequency of striped individuals was positively related to forest cover in populations occurring in warmer regions (\u3e7°C annually), a relationship that was weak to nonexistent in populations located in colder regions (≤7°C annually). Our results suggest that directional selection imposed by climate warming at a regional scale may be amplified by forest loss and suppressed by forest persistence, with a mediating effect of land use that varies geographically. Our work highlights how the complex interaction of selection pressures imposed by different components of global change may lead to divergent evolutionary trajectories among populations

Grain Sorghum (Milo) Production in Kentucky

Grain sorghum (Sorghum bicolor) (Figure 1) can be used for a variety of purposes including animal feed, unleavened breads, cakes, wallboard, starch, dextrose, brooms, ethanol, high quality wax, and alcoholic beverages. Grain sorghum produced in Kentucky is most commonly used for animal feed and was first grown here in the 1920s. Although acreage in Kentucky has fluctuated considerably over the years, yields have generally exceeded the national average since the 1970s (Figure 2), indicating that grain sorghum is an option for producers interested in diversifying grain crop operations

Behavioral strategies during incubation influence nest and female survival of Wild Turkeys

Females must balance physiological and behavioral demands of producing offspring with associated expenditures, such as resource acquisition and predator avoidance. Nest success is an important parameter underlying avian population dynamics. Galliforms are particularly susceptible to low nest success due to exposure of ground nests to multiple predator guilds, lengthy incubation periods, and substantive reliance on crypsis for survival. Hence, it is plausible that nesting individuals prioritize productivity and survival differently, resulting in a gradient of reproductive strategies. Fine-scale movement patterns during incubation are not well documented in ground-nesting birds, and the influence of reproductive movements on survival is largely unknown. Using GPS data collected from female wild turkeys (n = 278) across the southeastern United States, we evaluated the influence of incubation recess behaviors on trade-offs between nest and female survival. We quantified daily recess behaviors including recess duration, recess frequency, total distance traveled, and incubation range size for each nest attempt as well as covariates for nest concealment, nest attempt, and nest age. Of 374 nests, 91 (24%) hatched and 39 (14%) females were depredated during incubation. Average nest survival during the incubation period was 0.19, whereas average female survival was 0.78. On average, females took 1.6 daily unique recesses (SD = 1.2), spent 2.1 hr off the nest each day (SD = 1.8), and traveled 357.6 m during recesses (SD = 396.6). Average nest concealment was 92.5 cm (SD = 47). We found that females who took longer recess bouts had higher individual survival, but had increased nest loss. Females who recessed more frequently had lower individual survival. Our findings suggest behavioral decisions made during incubation represent life-history trade-offs between predation risk and reproductive success on an unpredictable landscape

Promoting hygienic weaning food handling practices through a community-based programme: intervention implementation and baseline characteristics for a cluster randomised controlled trial in rural Gambia.

OBJECTIVE: Contamination of weaning food leads to diarrhoea in children under 5 years. Public health interventions to improve practices in low-income and middle-income countries are rare and often not evaluated using a randomised method. We describe an intervention implementation and provide baseline data for such a trial. DESIGN: Clustered randomised controlled trial. SETTING: Rural Gambia. PARTICIPANTS: 15 villages/clusters each with 20 randomly selected mothers with children aged 6-24 months per arm. INTERVENTION: To develop the public health intervention, we used: (A) formative research findings to determine theoretically based critical control point corrective measures and motivational drives for behaviour change of mothers; (B) lessons from a community-based weaning food hygiene programme in Nepal and a handwashing intervention programme in India; and (C) culturally based performing arts, competitions and environmental clues. Four intensive intervention days per village involved the existing health systems and village/cultural structures that enabled per-protocol implementation and engagement of whole villager communities. RESULTS: Baseline village and mother's characteristics were balanced between the arms after randomisation. Most villages were farming villages accessing health centres within 10 miles, with no schools but numerous village committees and representing all Gambia's three main ethnic groups. Mothers were mainly illiterate (60%) and farmers (92%); 24% and 10% of children under 5 years were reported to have diarrhoea and respiratory symptoms, respectively, in the last 7 days (dry season). Intervention process engaged whole village members and provided lessons for future implementation; culturally adapted performing arts were an important element. CONCLUSION: This research has potential as a new low-cost and broadly available public health programme to reduce infection through weaning food. The theory-based intervention was widely consulted in the Gambia and with experts and was well accepted by the communities. Baseline analysis provides socioeconomic data and confirmation of Unicefs Multiple Indicator Cluster Survey (MICS) data on the prevalence of diarrhoea and respiratory symptoms in the dry season in the poorest region of Gambia. TRIAL REGISTRATION NUMBER: PACTR201410000859336; Pre-results

Automated prediction of mastitis infection patterns in dairy herds using machine learning

© 2020, The Author(s). Mastitis in dairy cattle is extremely costly both in economic and welfare terms and is one of the most significant drivers of antimicrobial usage in dairy cattle. A critical step in the prevention of mastitis is the diagnosis of the predominant route of transmission of pathogens into either contagious (CONT) or environmental (ENV), with environmental being further subdivided as transmission during either the nonlactating “dry” period (EDP) or lactating period (EL). Using data from 1000 farms, random forest algorithms were able to replicate the complex herd level diagnoses made by specialist veterinary clinicians with a high degree of accuracy. An accuracy of 98%, positive predictive value (PPV) of 86% and negative predictive value (NPV) of 99% was achieved for the diagnosis of CONT vs ENV (with CONT as a “positive” diagnosis), and an accuracy of 78%, PPV of 76% and NPV of 81% for the diagnosis of EDP vs EL (with EDP as a “positive” diagnosis). An accurate, automated mastitis diagnosis tool has great potential to aid non-specialist veterinary clinicians to make a rapid herd level diagnosis and promptly implement appropriate control measures for an extremely damaging disease in terms of animal health, productivity, welfare and antimicrobial use