39,752 research outputs found

    Diversity-based pool of models for dealing with recurring concepts

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    A survey on machine learning for recurring concept drifting data streams

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    The problem of concept drift has gained a lot of attention in recent years. This aspect is key in many domains exhibiting non-stationary as well as cyclic patterns and structural breaks affecting their generative processes. In this survey, we review the relevant literature to deal with regime changes in the behaviour of continuous data streams. The study starts with a general introduction to the field of data stream learning, describing recent works on passive or active mechanisms to adapt or detect concept drifts, frequent challenges in this area, and related performance metrics. Then, different supervised and non-supervised approaches such as online ensembles, meta-learning and model-based clustering that can be used to deal with seasonalities in a data stream are covered. The aim is to point out new research trends and give future research directions on the usage of machine learning techniques for data streams which can help in the event of shifts and recurrences in continuous learning scenarios in near real-time

    Outsourcing Back Office Services in Small Nonprofits: Pitfalls and Possibilities

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    Presents findings on small nonprofits' administrative, finance, and other office support needs; reasons and conditions for outsourcing as well as barriers; methods for evaluating options; and guiding principles. Examines three business models

    A survey on online active learning

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    Online active learning is a paradigm in machine learning that aims to select the most informative data points to label from a data stream. The problem of minimizing the cost associated with collecting labeled observations has gained a lot of attention in recent years, particularly in real-world applications where data is only available in an unlabeled form. Annotating each observation can be time-consuming and costly, making it difficult to obtain large amounts of labeled data. To overcome this issue, many active learning strategies have been proposed in the last decades, aiming to select the most informative observations for labeling in order to improve the performance of machine learning models. These approaches can be broadly divided into two categories: static pool-based and stream-based active learning. Pool-based active learning involves selecting a subset of observations from a closed pool of unlabeled data, and it has been the focus of many surveys and literature reviews. However, the growing availability of data streams has led to an increase in the number of approaches that focus on online active learning, which involves continuously selecting and labeling observations as they arrive in a stream. This work aims to provide an overview of the most recently proposed approaches for selecting the most informative observations from data streams in the context of online active learning. We review the various techniques that have been proposed and discuss their strengths and limitations, as well as the challenges and opportunities that exist in this area of research. Our review aims to provide a comprehensive and up-to-date overview of the field and to highlight directions for future work

    The sustainable delivery of sexual violence prevention education in schools

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    Sexual violence is a crime that cannot be ignored: it causes our communities significant consequences including heavy economic costs, and evidence of its effects can be seen in our criminal justice system, public health system, Accident Compensation Corporation (ACC), and education system, particularly in our schools. Many agencies throughout New Zealand work to end sexual violence. Auckland-based Rape Prevention Education: Whakatu Mauri (RPE) is one such agency, and is committed to preventing sexual violence by providing a range of programmes and initiatives, information, education, and advocacy to a broad range of audiences. Up until early 2014 RPE employed one or two full-time positions dedicated to co-ordinating and training a large pool (up to 15) of educators on casual contracts to deliver their main school-based programmes, BodySafe – approximately 450 modules per year, delivered to some 20 high schools. Each year several of the contract educators, many of whom were tertiary students, found secure full time employment elsewhere. To retain sufficient contract educators to deliver its BodySafe contract meant that RPE had to recruit, induct and train new educators two to three times every year. This model was expensive, resource intense, and ultimately untenable. The Executive Director and core staff at RPE wanted to develop a more efficient and stable model of delivery that fitted its scarce resources. To enable RPE to know what the most efficient model was nationally and internationally, with Ministry of Justice funding, RPE commissioned Massey University to undertake this report reviewing national and international research on sexual violence prevention education (SVPE)

    The sustainable delivery of sexual violence prevention education in schools

    Get PDF
    Sexual violence is a crime that cannot be ignored: it causes our communities significant consequences including heavy economic costs, and evidence of its effects can be seen in our criminal justice system, public health system, Accident Compensation Corporation (ACC), and education system, particularly in our schools. Many agencies throughout New Zealand work to end sexual violence. Auckland-based Rape Prevention Education: Whakatu Mauri (RPE) is one such agency, and is committed to preventing sexual violence by providing a range of programmes and initiatives, information, education, and advocacy to a broad range of audiences. Up until early 2014 RPE employed one or two full-time positions dedicated to co-ordinating and training a large pool (up to 15) of educators on casual contracts to deliver their main school-based programmes, BodySafe – approximately 450 modules per year, delivered to some 20 high schools. Each year several of the contract educators, many of whom were tertiary students, found secure full time employment elsewhere. To retain sufficient contract educators to deliver its BodySafe contract meant that RPE had to recruit, induct and train new educators two to three times every year. This model was expensive, resource intense, and ultimately untenable. The Executive Director and core staff at RPE wanted to develop a more efficient and stable model of delivery that fitted its scarce resources. To enable RPE to know what the most efficient model was nationally and internationally, with Ministry of Justice funding, RPE commissioned Massey University to undertake this report reviewing national and international research on sexual violence prevention education (SVPE). [Background from Executive Summary.]Rape Prevention Education: Whakatu Maur

    Holobiont Evolution: Mathematical Model with Vertical vs. Horizontal Microbiome Transmission

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    A holobiont is a composite organism consisting of a host together with its microbiome, such as a coral with its zooxanthellae. To explain the often intimate integration between hosts and their microbiomes, some investigators contend that selection operates on holobionts as a unit and view the microbiome’s genes as extending the host’s nuclear genome to jointly comprise a hologenome. Because vertical transmission of microbiomes is uncommon, other investigators contend that holobiont selection cannot be effective because a holobiont’s microbiome is an acquired condition rather than an inherited trait. This disagreement invites a simple mathematical model to see how holobiont selection might operate and to assess its plausibility as an evolutionary force. This paper presents two variants of such a model. In one variant, juvenile hosts obtain microbiomes from their parents (vertical transmission). In the other variant, microbiomes of juvenile hosts are assembled from source pools containing the combined microbiomes of all parents (horizontal transmission). According to both variants, holobiont selection indeed causes evolutionary change in holobiont traits. Therefore, holobiont selection is plausibly an effective evolutionary force with either mode of microbiome transmission. The modeling employs two distinct concepts of inheritance, depending on the mode of microbiome transmission: collective inheritance whereby juveniles inherit a sample of the collected genomes from all parents, as contrasted with lineal inheritance whereby juveniles inherit the genomes from only their own parents. A distinction between collective and lineal inheritance also features in theories of multilevel selection
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