352,726 research outputs found

    Ratio estimators in agricultural research : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Statistics at Massey University, Palmerston North, New Zealand

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    This thesis addresses the problem of estimating the ratio of quantitative variables from several independent samples in agricultural research. The first part is concerned with estimating a binomial proportion, the ratio of discrete counts, from several independent samples under the assumption that there is a single underlying binomial proportion p in the population of interest. The distributions and properties of two linear estimators, a weighted average and an arithmetic average, are derived and merits of the approaches discussed. They are both unbiased estimators of the population proportion, with the weighted average having lower variability than the arithmetic average. These findings are obtained through a first principles analysis, with a geometrical interpretation presented. This variability result is also a consequence of the Rao-Blackwell theorem, a well-known result in the theory of statistical inference. Both estimators are used in the literature but we conclude that the weighted average estimate should always be used when the sample sizes are unequal. These results are illustrated by a simulation experiment and are validated using survey data in the study of lodging percentage of sunflower cultivar, Improved Peredovic, in Jilin Province, China in 1994. The second part of the research addresses the problem of estimating the ratio ÎŒÍŻ / ÎŒ, of the means of continuous variables in agricultural research. The distributional properties of the ratio X/Y of independent normal variables are examined, both theoretically and using simulation. The results show that the moments of the ratio do not exist in general. The moments exist, however, for a punctured normal distribution of the denominator variable if we only sample points for which | Y |>Δ, Δ being a small positive quantity. We draw out the practical rule-of-thumb that the ratio of two independent normal variables can be used to estimate ÎŒÍŻ / ÎŒ, when the coefficient of variation of the denominator variable is sufficiently small (less than or equal to 0.2). Lastly the thesis evaluates the relative merits of two common estimators of the ratio of the means of continuous variables in agricultural research, an arithmetic average and a weighted average, via simulation experiments using normal distributions. In the first simulation, the ratio and common coefficient of variation are changed while the sample size is kept moderately large. In the second simulation, the ratio and sample size are changed while the coefficient of variation is held constant. Results show that the weighted average always provides a better estimate of the true ratio and has lower variability than the arithmetic average. It is recommended that the weighted average be used for estimating the ratio from several pairs of observations. These results are tested using research data from rice breeding multi-environment trials in Jilin Province, China in 1995 and 1996. These data are used to demonstrate the diagnostic approach developed for assessing the 'safety' use of the arithmetic and the weighted average methods for estimating the ratio of the means of independent normal variables

    Describing typeforms: a designer's response

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    The paper sets out an overview of a pragmatic research investigation initiated within a doctoral enquiry, and which continues to inform design practice and pedagogy. Located within the fields of typography and information design, and very much concerned with design history, enquiry emphasized exploration of alternative design research methodologies in the production of a design outcome loaded with pedagogical ambition. The issue being addressed within the investigation was the limited scope of existing typeface classificatory systems to adequately describe the diversity of forms represented within current type design practice and thus, recent acquisitions to an established teaching collection in London. Addressing this issue unexpectedly came to utilize the researcher’s own design practice as a methodology for managing emergent enquiry, and for organizing and generating new knowledge through the employment of visual information management methods. A primary outcome of the enquiry was a new framework for the description of typeforms. This new framework will be described in terms of its operation, divergence from existing models and potential for application

    Cultivating knowledge sharing through the relationship management maturity model

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    Purpose - The purpose of this paper is to present the development of the relationship management maturity model (RMMM), the output of an initiative aimed at bridging the gap between business units and the IT organisation. It does this through improving and assessing knowledge sharing between business and IT staff in Finco, a large financial services organisation. Design/methodology/approach - The objectives were achieved by undertaking ethnographic research with the relationship managers (RMs) as they carried out their activities, and developing the RMMM by visualizing the development of a community of practice (CoP) between business and IT. Findings - The RMMM demonstrates a learning mechanism to bridge the business/IT gap through an interpretive approach to knowledge sharing by defining knowledge sharing processes between business and IT and defining the tasks of the relationship managers as facilitators of knowledge sharing. Research limitations/implications - More research is necessary to determine whether the RMMM is a useful tool on which Finco can base the development of RM over the next few years. Practical implications - The RMMM acts as a practical knowledge management tool, and will act as a future reference for the RMs as they attempt to further develop the business/IT relationship. Originality/value - The findings provide an initial endorsement of the knowledge sharing perspective to understand the business/IT relationship. Also, the RMMM can be used to identify problematic issues and develop processes to address them

    An ontology co-design method for the co-creation of a continuous care ontology

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    Ontology engineering methodologies tend to emphasize the role of the knowledge engineer or require a very active role of domain experts. In this paper, a participatory ontology engineering method is described that holds the middle ground between these two 'extremes'. After thorough ethnographic research, an interdisciplinary group of domain experts closely interacted with ontology engineers and social scientists in a series of workshops. Once a preliminary ontology was developed, a dynamic care request system was built using the ontology. Additional workshops were organized involving a broader group of domain experts to ensure the applicability of the ontology across continuous care settings. The proposed method successfully actively engaged domain experts in constructing the ontology, without overburdening them. Its applicability is illustrated by presenting the co-created continuous care ontology. The lessons learned during the design and execution of the approach are also presented

    Video Stream Retrieval of Unseen Queries using Semantic Memory

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    Retrieval of live, user-broadcast video streams is an under-addressed and increasingly relevant challenge. The on-line nature of the problem requires temporal evaluation and the unforeseeable scope of potential queries motivates an approach which can accommodate arbitrary search queries. To account for the breadth of possible queries, we adopt a no-example approach to query retrieval, which uses a query's semantic relatedness to pre-trained concept classifiers. To adapt to shifting video content, we propose memory pooling and memory welling methods that favor recent information over long past content. We identify two stream retrieval tasks, instantaneous retrieval at any particular time and continuous retrieval over a prolonged duration, and propose means for evaluating them. Three large scale video datasets are adapted to the challenge of stream retrieval. We report results for our search methods on the new stream retrieval tasks, as well as demonstrate their efficacy in a traditional, non-streaming video task.Comment: Presented at BMVC 2016, British Machine Vision Conference, 201

    WGBH's Teacher's Domain: Producing Open Materials and Engaging Users

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    Launched in 2002 by WGBH, the non-commercial public media service, located in Boston, Massachusetts, Teachers' Domain is an online repository of multimedia open educational resources for use in classrooms and for professional development. As part of its effort to increase the availability of freely accessible resources WGBH has developed content from public media archives into high quality, open educational resources for Teachers' Domain. Using a participatory case study methodology, this report examines WGBH and Teachers' Domain's successes and challenges in 1) converting proprietary content to open content 2) engaging users in content and 3) redesigning the Teacher's Domain site to accommodate new categories of use and tools for teachers and learners of all different backgrounds and activity levels. For OER projects more generally, ongoing research on user behaviors, experiences and perceptions can be a challenging and resource-intense process; however, by assessing and building data collection mechanisms and research questions into organizational practices, knowledge and learnings can be cultivated to inform how users are best supported, as well as to inform continuous improvement for the projects overall

    The impact of a multi-strategy academic writing handbook on Emergent bilinguals’ cross-curricular writing competences

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    La escritura acadĂ©mica en una segunda lengua puede ser uno de los requerimientos mĂĄs complejos en la educaciĂłn superior debido a los elementos lingĂŒĂ­sticos, estratĂ©gicos y procedimentales que esta abarca al igual que los procesos cognitivos superiores que involucra. A pesar de su presencia permanente en la academia, los profesores no han encontrado aĂșn una forma apropiada para enseñar y evaluar la escritura que garantice el progreso de los estudiantes y el apoyo continuo a lo largo de su proceso de aprendizaje. De esta manera, este estudio de caso de mĂ©todos mixtos apunta a diseñar y evaluar la efectividad de un Manual de Referencia para la Escritura AcadĂ©mica (MREA) que pretende proveer la asistencia constante que los estudiantes necesitan para solidificar su conocimiento de escritura y el material pedagĂłgico apropiado que los docentes requieren para unificar los prĂĄcticas de enseñanza y evaluaciĂłn de la escritura; este manual estĂĄ fundamentado en los enfoques de la escrita como proceso y basada en el gĂ©nero, anĂĄlisis de errores y evaluaciĂłn..

    Ranking relations using analogies in biological and information networks

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    Analogical reasoning depends fundamentally on the ability to learn and generalize about relations between objects. We develop an approach to relational learning which, given a set of pairs of objects S={A(1):B(1),A(2):B(2),
,A(N):B(N)}\mathbf{S}=\{A^{(1)}:B^{(1)},A^{(2)}:B^{(2)},\ldots,A^{(N)}:B ^{(N)}\}, measures how well other pairs A:B fit in with the set S\mathbf{S}. Our work addresses the following question: is the relation between objects A and B analogous to those relations found in S\mathbf{S}? Such questions are particularly relevant in information retrieval, where an investigator might want to search for analogous pairs of objects that match the query set of interest. There are many ways in which objects can be related, making the task of measuring analogies very challenging. Our approach combines a similarity measure on function spaces with Bayesian analysis to produce a ranking. It requires data containing features of the objects of interest and a link matrix specifying which relationships exist; no further attributes of such relationships are necessary. We illustrate the potential of our method on text analysis and information networks. An application on discovering functional interactions between pairs of proteins is discussed in detail, where we show that our approach can work in practice even if a small set of protein pairs is provided.Comment: Published in at http://dx.doi.org/10.1214/09-AOAS321 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org
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