2,666 research outputs found
Consideration of Interference Correlation Properties in a JD-CDMA Mobile Radio System with Coherent Receiver Antenna Diversity
No full textIn code division multiple access (CDMA) mobile radio systems, both intersymbol interference and multiple access interference arise which can be combatted by using Joint Detection (JD) techniques, to reduce the degradation in performance resulting from time variance, coherent receiver antenna diversity (CRAD) can be used. The application of JD techniques offers the possibility to exploit the knowledge of noise covariances at the receiver. If only intercell (cochannel) interference is considered, the noise covariances in the uplink receiver of a multiple receiver antenna CDMA mobile radio system depend mainly on the directions of arrival (DOAs) of the interfering signals and the receiver antenna placement. Therefore, if the interferer DOAs are known at the base station, these covariances could be estimated. In this thesis, a realistic model of the uplink of a JD CDMA mobile radio system with CRAD is described in which the above mentioned interference cancelling method is used. Simulation results according to this model are given and evaluated.Applied SciencesElectrical EngineeringTelecommunications and Traffic Control Systems Grou
Modeling robot co-representation: state-of-the-art, open issues, and predictive learning as a possible framework
No full textRobots are getting increasingly more present in many spheres of human life, making the need for robots that can successfully engage in natural social interactions with humans paramount. Successful human-robot interaction could be achieved more effectively if robots could act predictably and could predict the humans' actions. If robots could represent human partners and generate behaviors that are in line with the partners' expectations based on human's mental models of interdependent action, human agents would be able to apply predictive and adaptive mechanisms acquired in human interactions to interact with robots effectively. How could robots be predictable and be capable of predicting human behavior? We propose that this could be achieved by having an internal representation of both oneself and the other agent, that is by equipping the robot with the ability to co-represent. Here, co-representation refers to the representation of the partner's actions alongside one's own actions. Although co-representation constitutes an essential process for successful human social interaction, as it supports understanding of others' actions, to date co-representation processes have only scarcely been integrated into robotic platforms. We highlight the state-of-the-art findings on co-representation in social robotics, discuss current research limitations and open issues for creating computational models of co-representation in robots, and put forward the idea that predictive learning might constitute a particularly promising framework to build models of co-representing robots. Overall, in this article, we offer an integrated view of the state-of-the-art findings in robotics literature on co-representation and outline directions for future research, with the aim to boost success in building robots equipped with co-representation models fit for smooth social interactions
Dairy farmers’ perceptions toward the implementation of on-farm Johne’s disease prevention and control strategies
No full textmplementation of specific management strategies on dairy farms is currently the most effective way to reduce the prevalence of Johne’s disease (JD), an infectious chronic enteritis of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP). However, dairy farmers often fail to implement recommended strategies. The objective of this study was to assess perceptions of farmers participating in a JD prevention and control program toward recommended practices, and explore factors that influence whether or not a farmer adopts risk-reducing measures for MAP transmission. Semi-structured interviews were conducted with 25 dairy farmers enrolled in a voluntary JD control program in Alberta, Canada. Principles of classical grounded theory were used for participant selection, interviewing, and data analysis. Additionally, demographic data and MAP infection status were collected and analyzed using quantitative questionnaires and the JD control program database. Farmers’ perceptions were distinguished according to 2 main categories: first, their belief in the importance of JD, and second, their belief in recommended JD prevention and control strategies. Based on these categories, farmers were classified into 4 groups: proactivists, disillusionists, deniers, and unconcerned. The first 2 groups believed in the importance of JD, and proactivists and unconcerned believed in proposed JD prevention and control measures. Groups that regarded JD as important had better knowledge about best strategies to reduce MAP transmission and had more JD risk assessments conducted on their farm. Although not quantified, it also appeared that these groups had more JD prevention and control practices in place. However, often JD was not perceived as a problem in the herd and generally farmers did not regard JD control as a “hot topic” in communications with their herd veterinarian and other farmers. Recommendations regarding how to communicate with farmers and motivate various groups of farmers according to their specific perceptions were provided to optimize adoption of JD prevention and control measures and thereby increase success of voluntary JD control programs
Environmental Demands and Resources: A Framework for Understanding the Physical Environment for Work
No full textPurpose
The purpose of this paper is to explore the extent to which Job Demands-Resources (JD-R) theory (Demerouti et al., 2001; Bakker and Demerouti, 2017) is an appropriate conceptual framework for understanding the physical environment for work.
Design/methodology/approach
A conceptual analysis of the multidisciplinary workplace literature was performed to assess the core propositions of JD-R theory as they relate to the workplace environment.
Findings
The analysis confirms that the workplace environment can be viewed as a composite of environmental demands (which instigate a health impairment process) and environmental resources (which trigger an engagement process). Employees proactively try to improve the suitability of their workspace through environmental crafting, motivated by minimising demands and maximising resources.
Originality/value
The application of JD-R theory to the workplace environment fills a gap in the literature for a framework which captures the dynamic nature of the employee-workplace relationship
Knowledge gaps that hamper prevention and control of Mycobacterium avium subspecies paratuberculosis infection
No full textIn the last decades, many regional and country‐wide control programmes for Johne's disease (JD ) were developed due to associated economic losses, or because of a possible association with Crohn's disease. These control programmes were often not successful, partly because management protocols were not followed, including the introduction of infected replacement cattle, because tests to identify infected animals were unreliable, and uptake by farmers was not high enough because of a perceived low return on investment. In the absence of a cure or effective commercial vaccines, control of JD is currently primarily based on herd management strategies to avoid infection of cattle and restrict within‐farm and farm‐to‐farm transmission. Although JD control programmes have been implemented in most developed countries, lessons learned from JD prevention and control programmes are underreported. Also, JD control programmes are typically evaluated in a limited number of herds and the duration of the study is less than 5 year, making it difficult to adequately assess the efficacy of control programmes. In this manuscript, we identify the most important gaps in knowledge hampering JD prevention and control programmes, including vaccination and diagnostics. Secondly, we discuss directions that research should take to address those knowledge gaps
Evaluation of an alternative method of herd classification for infection with paratuberculosis in cattle herds in the United States
No full textObjective - To develop a better system for classification of herd infection status for paratuberculosis (Johne's disease JD]) in US cattle herds on the basis of the risk of potential transmission of Mycobacterium avium subsp paratubeculosis. Sample - Simulated data for herd size and within-herd prevalence; sensitivity and specificity for test methods obtained from consensus-based estimates. Procedures - Interrelationships among variables influencing interpretation and classification of herd infection status for JD were evaluated by use of simulated data for various herd sizes, true within-herd prevalences, and sampling and testing methods. The probability of finding ≥1 infected animal in herds was estimated for various testing methods and sample sizes by use of hypergeometric random sampling. Results - 2 main components were required for the new herd JD classification system: the probability of detection of infection determined on the basis of test results from a sample of animals and the maximum detected number of animals with positive test results. Tables were constructed of the estimated probability of detection of infection, and the maximum number of cattle with positive test results or fecal pools with positive culture results with 95% confidence for classification of herd JD infection status were plotted. Herd risk for JD was categorized on the basis of 95% confidence that the true within-herd prevalence was ≤15%, ≤10%, ≤5%, or ≤2%. Conclusions and Clinical Relevance - Analysis of the findings indicated that a scientifically rigorous and transparent herd classification system for JD in cattle is feasible.Source type: Electronic(1
Factors associated with participation of Alberta dairy farmers in a voluntary, management-based Johne’s disease control program
No full textThe Alberta Johne's Disease Initiative (AJDI) is a voluntary, management-based prevention and control program for Johne's disease (JD), a wasting disease in ruminants that causes substantial economic losses to the cattle industry. Despite extensive communication about the program's benefits and low cost to participating producers, approximately 35% of Alberta dairy farmers have not enrolled in the AJDI. Therefore, the objective was to identify differences between AJDI nonparticipants and participants that may influence enrollment. Standardized questionnaires were conducted in person on 163 farms not participating and 61 farms participating in the AJDI. Data collected included demographic characteristics, internal factors (e.g., attitudes and beliefs of the farmer toward JD and the AJDI), external factors (e.g., farmers' JD knowledge and on-farm goals and constraints), as well as farmers' use and influence of various information sources. Nonparticipants and participants differed in at least some aspects of all studied categories. Based on logistic regression, participating farms had larger herds, higher self-assessed knowledge of JD, better understanding of AJDI details before participation, and used their veterinarian more often to get information about new management practices and technologies when compared with nonparticipants. In contrast, nonparticipants indicated that time was a major on-farm constraint and that participation in the AJDI would take too much time. They also indicated that they preferred to wait and see how the program worked on other farms before they participated
Deadly meals: The influence of personal and job factors on burnout and risky riding behaviours of food delivery motorcyclists
No full textFood delivery riders are overrepresented in road crashes. Arguably, the increased risk experienced by food delivery riders is linked to the working conditions offered by the “gig economy”. Research is needed to fully understand the safety-related issues this vulnerable group of road users face daily and identify opportunities for counter measures. In this investigation, we proposed a new theoretical model to explain the risky behaviour of food delivery motorcyclists based on the well-established Job Demands-Resources (JD-R) model. Following the JD-R, we considered the impact of job demands (job aspects that require sustained effort) and job resources (job aspects that help achieve work-related goals, reduce job demands and stimulate personal development) on the risky riding behaviours of food delivery motorcyclists. The JD-R model was also extended with three constructs, including personal demands, personal resources, and perceived safety risk to explore the role of individuals' within-person aspects. The developed model was tested using data collected from 554 food delivery riders in the two biggest cities in Vietnam. The results showed that job burnout, job resources, and personal demands directly impact risky riding behaviours, in which job burnout was the most significant predictor. Constructs such as job demands, personal resources, and perceived safety risk were not significant predictors of risky riding behaviours. This research shows that organisation-level factors could be modified to prevent risky riding behaviour. The gig economy industry can do much more to improve the safety of delivery riders.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Safety and Security Scienc
Discovery of Gene Function by Expression Profiling of the Malaria Parasite Life Cycle
No full textThis is the companion web site for publication:Le Roch KG, Zhou Y, Blair PL, Grainger M, Moch JK, Haynes JD, De La Vega P, Holder AA, Batalov S, Carucci DJ, Winzeler EA. Discovery of gene function by expression profiling of the malaria parasite life cycle. Science. 2003 Sep 12;301(5639):1503-8. doi: 10.1126/science.1087025. Epub 2003 Jul 31. PMID: 12893887.Download and unzip the file, open CellCycle/index.html to browse the self-contained web site.</div
Dairy producer satisfaction and knowledge transfer with the veterinary-administered risk assessment and management plan in a voluntary Johne's disease control program
No full textThe Atlantic Johne's Disease Initiative (AJDI) aims to control Mycobacterium avium ssp. paratuberculosis infection by using veterinary-administered risk assessments to identify high-risk management practices and prompt changes in management behavior. Objectives for this study were to measure producer satisfaction with the veterinary-administered risk assessment and management plan (RAMP) process in a voluntary Johne's disease (JD) control program, compare RAMP-specific satisfaction results based on herd JD status, and measure knowledge transfer from certified veterinarians to producers during the RAMP. A satisfaction questionnaire was adapted to the RAMP process in the AJDI to measure producer satisfaction. The questionnaire included 9 RAMP-specific producer satisfaction items, 1 global RAMP satisfaction item, and 16 questions to assess producer knowledge and knowledge translation about JD, bovine viral diarrhea (BVD), and bovine leukosis virus (BLV) during the RAMP (BVD and BLV used for comparison purposes). A total of 133 dairy producers in the AJDI (79.6% response rate) completed the questionnaire by telephone. The RAMP-specific satisfaction was high among the AJDI producers surveyed, and these results were not found to differ based on herd JD status. The lowest satisfaction scores and the highest number of “unable to assess” responses were for the item relating to cost. Factors that contributed to RAMP-specific producer satisfaction were not identified from the demographic and herd information available in this study. The knowledge scores indicated moderate knowledge about JD and fair knowledge about BVD and BLV. Evidence of knowledge translation from the RAMP was mixed in this study. Bovine viral diarrhea knowledge scores were not found to differ based on whether or not the certified veterinarian discussed BVD during the preceding RAMP, but BLV knowledge scores were higher among dairy producers that discussed BLV during the preceding RAMP. Strengths and gaps in producer knowledge about these 3 infectious diseases were identified. By using this producer questionnaire, interventions aimed at improving the content, delivery, and satisfaction of RAMP in JD control programs, such as the AJDI, can be developed.Dairy Farmers of Prince Edward Island, Nova Scotia, New Brunswick, and Newfoundland and LabradorAgriculture and Agri-Foo
- …
