823 research outputs found

    Data-driven or background knowledge ontology development

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    The development of ontologies for various purposes is now a relatively commonplace process. A number of different approaches towards this aim are evident; empirical methodologies, giving rise to data-driven procedures or self-reflective (innate) methodologies, resulting in artifacts that are based on intellectual background understanding. In this paper, we compare and contrast these approaches through two practical examples, one from a descriptive metadata domain and one from the area of physical computing. Both examples are chosen from domains in which automated extraction of information is a significant use case for the resulting ontology. We identify a relationship within the ontology development process that allies empirical evidence and user judgement to develop user-centred ontologies, either on an individual or collaboratively-focused basis. A qualitative treatment of the characteristics of this type of 'language game' is identified as an ongoing research goal

    Trailer Park Kids: An Ethnographic Study Of Identity Formation In An Affluent Suburban Middle School

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    The purpose of this dissertation was determining influences behind identity formation, social reproduction, and resistance of students residing in a local manufactured home community and attending a suburban majority White, middle-and upper-middle class middle school. Narratives from participants were included to assist in disseminating intersecting lives of students (the trailer park kids) with their parents and teachers. The lives of the trailer park kids at home and at school were portrayed. Research before this study focused on similar themes, but unique was examination of effects on students attending school as a minority by social class standing and their place of residence. The settings were the manufactured home community (Waldenburg Acres) and the school (Kearney Middle School). Ethnographic methods were used to obtain data in the field. Eight students and one parent were interviewed three times each. Four high seniority teachers were also interviewed. Interviews took place at school, in homes of participants, at Waldenburg Acres clubhouse, or in local restaurants and coffee shops. Students were observed in their core curricular classrooms, hallways, the cafeteria and on the bus. Transcripts from interviews, field notes and research journal entries were included as part of the data analysis and discussion of findings. Exposing differences in the school day between the trailer park kids and the middle-and upper-middle class (single family home kids) surfaced as key to understanding findings. The trailer park kids experienced social isolation and curriculum alienation attributed to perceptions and bias of the single-family home kids and teachers. Teachers affectionately demonstrated culture of poverty beliefs that promoted stereotypes, a segregated existence and social reproduction for the trailer park kids. Resistance by both teachers and trailer park kids was passive in response to the culture of power in the school, held by the single-family home kids. Further examination of heterogeneous social class schools and schools where students from manufactured home communities attend was suggested to add to these findings. Implications of social class difference need to be explored in teacher education. Professional development for teachers that disrupts culture of poverty beliefs and exposes the non-neutral curriculum is needed

    Classification algorithms for Big Data with applications in the urban security domain

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    A classification algorithm is a versatile tool, that can serve as a predictor for the future or as an analytical tool to understand the past. Several obstacles prevent classification from scaling to a large Volume, Velocity, Variety or Value. The aim of this thesis is to scale distributed classification algorithms beyond current limits, assess the state-of-practice of Big Data machine learning frameworks and validate the effectiveness of a data science process in improving urban safety. We found in massive datasets with a number of large-domain categorical features a difficult challenge for existing classification algorithms. We propose associative classification as a possible answer, and develop several novel techniques to distribute the training of an associative classifier among parallel workers and improve the final quality of the model. The experiments, run on a real large-scale dataset with more than 4 billion records, confirmed the quality of the approach. To assess the state-of-practice of Big Data machine learning frameworks and streamline the process of integration and fine-tuning of the building blocks, we developed a generic, self-tuning tool to extract knowledge from network traffic measurements. The result is a system that offers human-readable models of the data with minimal user intervention, validated by experiments on large collections of real-world passive network measurements. A good portion of this dissertation is dedicated to the study of a data science process to improve urban safety. First, we shed some light on the feasibility of a system to monitor social messages from a city for emergency relief. We then propose a methodology to mine temporal patterns in social issues, like crimes. Finally, we propose a system to integrate the findings of Data Science on the citizenry’s perception of safety and communicate its results to decision makers in a timely manner. We applied and tested the system in a real Smart City scenario, set in Turin, Italy

    Attention Restraint, Working Memory Capacity, and Mind Wandering: Do Emotional Valence or Intentionality Matter?

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    Attention restraint appears to mediate the relationship between working memory capacity (WMC) and mind wandering (Kane et al., 2016). Prior work has identifed two dimensions of mind wandering—emotional valence and intentionality. However, less is known about how WMC and attention restraint correlate with these dimensions. Te current study examined the relationship between WMC, attention restraint, and mind wandering by emotional valence and intentionality. A confrmatory factor analysis demonstrated that WMC and attention restraint were strongly correlated, but only attention restraint was related to overall mind wandering, consistent with prior fndings. However, when examining the emotional valence of mind wandering, attention restraint and WMC were related to negatively and positively valenced, but not neutral, mind wandering. Attention restraint was also related to intentional but not unintentional mind wandering. Tese results suggest that WMC and attention restraint predict some, but not all, types of mind wandering

    Adolescent Development in Context: Social, Psychological, and Neurological Foundations

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    This project was funded by KU Libraries’ Parent’s Campaign with support from the David Shulenburger Office of Scholarly Communication & Copyright and the Open Educational Resources Working Group in the University of Kansas Libraries.Increasingly, there is a tendency to characterize the teenage years as a time of general moral degeneration and deviance. This is unfortunate because the teenage years represent a key developmental period of the typical human lifespan, and from an evolutionary point of view, the actual characteristics that define adolescence represent critical learning opportunities. The increased sensitivity to social influences, identity formation, and social-emotional skills are just a few of such opportunities that require appropriate environments and contexts for optimal, healthy outcomes. Research in the field of adolescent development has not been immune to the negative stereotypes surrounding adolescence, and it is common to see researchers, either implicitly or explicitly, refer to adolescence as a high-risk, anomalous developmental stage that must be controlled, managed, or simply endured until adult-level abilities emerge spontaneously as a result of having survived an intrinsically tumultuous developmental time. More enlightened views of adolescence recognize that all biological adaptations have a cause and a purpose, and that the purpose of adolescence can be discerned from understanding the complex evolutionary history of humans as a group-based, family-based, highly social, sometimes competitive, abstract-thinking species. Understanding the biological foundations of adolescence is meaningless if one does not also consider how biology and environment interact. In humans, these interactions are highly complex and involve not only immediate physical realities, but also social, cultural, and historical realities that create complex contexts and webs of interactions. Therefore, this textbook seeks to reconcile the biological and neurological foundations of human development with the psychological and sociological mechanisms that formed and continue to influence human developmental trajectories. To this end, we have divided the textbook into three main sections. The first, Foundations of Adolescent Development, introduces the historical science of studying adolescence and the biological foundations of puberty. The second section, Contexts of Adolescent Development, considers the primary contextual factors that influence developmental outcomes during adolescence. These include work and employment, peers, in-school and out-of-school contexts, leisure time, and the family. The final section, Milestones of Adolescent Development, addresses the primary psychological milestones that represent healthy adjustment to adult roles and responsibilities in society. The domains of these milestones include cognition and decision-making; identity, meaning, and purpose, moral development, and sexuality. From an educational point of view, the objective of this textbook is to provide a resource that is capable of fostering advanced conceptual change and learning in the field of adolescent development in order to go beyond stereotypical portrayals of adolescence as a pathological condition. Organized in a manner designed to scaffold increasingly complex ideas, the textbook redefines adolescence a sensitive period of development characterized by phylogenetically derived experience-expectant states and complex interactions of biological, psychological, and social factors. The textbook draws from the latest advances in neuroscience and psychology to construct a practical framework for use in a wide range of academic and professional contexts, and it presents historical as well as contemporary research to accomplish a radical redefining of an often misunderstood and maligned developmental period

    Behavioral Task Modeling for Entity Recommendation

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    Our everyday tasks involve interactions with a wide range of information. The information that we manage is often associated with a task context. However, current computer systems do not organize information in this way, do not help the user find information in task context, but require explicit user actions such as searching and information seeking. We explore the use of task context to guide the delivery of information to the user proactively, that is, to have the right information easily available at the right time. In this thesis, we used two types of novel contextual information: 24/7 behavioral recordings and spoken conversations for task modeling. The task context is created by monitoring the user's information behavior from temporal, social, and topical aspects; that can be contextualized by several entities such as applications, documents, people, time, and various keywords determining the task. By tracking the association amongst the entities, we can infer the user's task context, predict future information access, and proactively retrieve relevant information for the task at hand. The approach is validated with a series of field studies, in which altogether 47 participants voluntarily installed a screen monitoring system on their laptops 24/7 to collect available digital activities, and their spoken conversations were recorded. Different aspects of the data were considered to train the models. In the evaluation, we treated information sourced from several applications, spoken conversations, and various aspects of the data as different kinds of influence on the prediction performance. The combined influences of multiple data sources and aspects were also considered in the models. Our findings revealed that task information could be found in a variety of applications and spoken conversations. In addition, we found that task context models that consider behavioral information captured from the computer screen and spoken conversations could yield a promising improvement in recommendation quality compared to the conventional modeling approach that considered only pre-determined interaction logs, such as query logs or Web browsing history. We also showed how a task context model could support the users' work performance, reducing their effort in searching by ranking and suggesting relevant information. Our results and findings have direct implications for information personalization and recommendation systems that leverage contextual information to predict and proactively present personalized information to the user to improve the interaction experience with the computer systems.Jokapäiväisiin tehtäviimme kuuluu vuorovaikutusta monenlaisten tietojen kanssa. Hallitsemamme tiedot liittyvät usein johonkin tehtäväkontekstiin. Nykyiset tietokonejärjestelmät eivät kuitenkaan järjestä tietoja tällä tavalla tai auta käyttäjää löytämään tietoja tehtäväkontekstista, vaan vaativat käyttäjältä eksplisiittisiä toimia, kuten tietojen hakua ja etsimistä. Tutkimme, kuinka tehtäväkontekstia voidaan käyttää ohjaamaan tietojen toimittamista käyttäjälle ennakoivasti, eli siten, että oikeat tiedot olisivat helposti saatavilla oikeaan aikaan. Tässä väitöskirjassa käytimme kahdenlaisia uusia kontekstuaalisia tietoja: 24/7-käyttäytymistallenteita ja tehtävän mallintamiseen liittyviä puhuttuja keskusteluja. Tehtäväkonteksti luodaan seuraamalla käyttäjän tietokäyttäytymistä ajallisista, sosiaalisista ja ajankohtaisista näkökulmista katsoen; sitä voidaan kuvata useilla entiteeteillä, kuten sovelluksilla, asiakirjoilla, henkilöillä, ajalla ja erilaisilla tehtävää määrittävillä avainsanoilla. Tarkastelemalla näiden entiteettien välisiä yhteyksiä voimme päätellä käyttäjän tehtäväkontekstin, ennustaa tulevaa tiedon käyttöä ja hakea ennakoivasti käsillä olevaan tehtävään liittyviä asiaankuuluvia tietoja. Tätä lähestymistapaa arvioitiin kenttätutkimuksilla, joissa yhteensä 47 osallistujaa asensi vapaaehtoisesti kannettaviin tietokoneisiinsa näytönvalvontajärjestelmän, jolla voitiin 24/7 kerätä heidän saatavilla oleva digitaalinen toimintansa, ja joissa tallennettiin myös heidän puhutut keskustelunsa. Mallien kouluttamisessa otettiin huomioon datan eri piirteet. Arvioinnissa käsittelimme useista sovelluksista, puhutuista keskusteluista ja datan eri piirteistä saatuja tietoja erilaisina vaikutuksina ennusteiden toimivuuteen. Malleissa otettiin huomioon myös useiden tietolähteiden ja näkökohtien yhteisvaikutukset. Havaintomme paljastivat, että tehtävätietoja löytyi useista sovelluksista ja puhutuista keskusteluista. Lisäksi havaitsimme, että tehtäväkontekstimallit, joissa otetaan huomioon tietokoneen näytöltä ja puhutuista keskusteluista saadut käyttäytymistiedot, voivat parantaa suositusten laatua verrattuna tavanomaiseen mallinnustapaan, jossa tarkastellaan vain ennalta määritettyjä vuorovaikutuslokeja, kuten kyselylokeja tai verkonselaushistoriaa. Osoitimme myös, miten tehtäväkontekstimalli pystyi tukemaan käyttäjien suoritusta ja vähentämään heidän hakuihin tarvitsemaansa työpanosta järjestämällä hakutuloksia ja ehdottamalla heille asiaankuuluvia tietoja. Tuloksillamme ja havainnoillamme on suoria vaikutuksia tietojen personointi- ja suositusjärjestelmiin, jotka hyödyntävät kontekstuaalista tietoa ennustaakseen ja esittääkseen ennakoivasti personoituja tietoja käyttäjälle ja näin parantaakseen vuorovaikutuskokemusta tietokonejärjestelmien kanssa

    Distributed analysis of vertically partitioned sensor measurements under communication constraints

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    Nowadays, large amounts of data are automatically generated by devices and sensors. They measure, for instance, parameters of production processes, environmental conditions of transported goods, energy consumption of smart homes, traffic volume, air pollution and water consumption, or pulse and blood pressure of individuals. The collection and transmission of data is enabled by electronics, software, sensors and network connectivity embedded into physical objects. The objects and infrastructure connecting such objects are called the Internet of Things (IoT). In 2010, already 12.5 billion devices were connected to the IoT, a number about twice as large as the world's population at that time. The IoT provides us with data about our physical environment, at a level of detail never known before in human history. Understanding such data creates opportunities to improve our way of living, learning, working, and entertaining. For instance, the information obtained from data analysis modules embedded into existing processes could help their optimization, leading to more sustainable systems which save resources in sectors such as manufacturing, logistics, energy and utilities, the public sector, or healthcare. IoT's inherent distributed nature, the resource constraints and dynamism of its networked participants, as well as the amounts and diverse types of data collected are challenging even the most advanced automated data analysis methods known today. Currently, there is a strong research focus on the centralization of all data in the cloud, processing it according to the paradigm of parallel high-performance computing. However, the resources of devices and sensors at the data generating side might not suffice to transmit all data. For instance, pervasive distributed systems such as wireless sensors networks are highly communication-constrained, as are streaming high throughput applications, or those where data masses are simply too huge to be sent over existing communication lines, like satellite connections. Hence, the IoT requires a new generation of distributed algorithms which are resource-aware and intelligently reduce the amount of data transmitted and processed throughout the analysis chain. This thesis deals with the distributed analysis of vertically partitioned sensor measurements under communication constraints, which is a particularly challenging scenario. Here, not observations are distributed over nodes, but their feature values. The learning of accurate prediction models may require the combination of information from different nodes, necessarily leading to communication. The main question is how to design communication-efficient algorithms for the scenario, while at the same time preserving sufficient accuracy. The first part of the thesis introduces fundamental concepts. An overview of the IoT and its many applications is given, with a special focus on data analysis, the vertically partitioned data scenario, and accompanying research questions. Then, basic notions of machine learning and data mining are introduced. A selection of existing distributed data mining approaches is presented and discussed in more detail. Distributed learning in the vertically partitioned data scenario is then motivated by a smart manufacturing case study. In a hot rolling mill, different machines assess parameters describing the processing of single steel blocks, whose quality should be predicted as early as possible, by analysis of distributed measurements. Each machine creates not single value series, but many of them. Their heterogeneity leads to challenging questions concerning the steps of preprocessing and finding a good representation for learning, for which solutions are proposed. Another problem is that quality information is not given for individual blocks, but charges of blocks. How can we nevertheless predict the quality of individual blocks? Time constraints lead to questions typical for the vertically partitioned data scenario. Which data should be analyzed locally, to match the constraints, and which should be sent to a central server? Learning from aggregated label information is a relatively novel problem in machine learning research. A new algorithm for the task is developed and evaluated, the Learning from Label Proportions by Clustering (LLPC) algorithm. The algorithm's performance is compared to three other state-of-the-art approaches, in terms of accuracy and running time. It can be shown that LLPC achieves results with lower running time, while accuracy is comparable to that of its competitors, or significantly higher. The proposed algorithm comes with many other benefits, like ease of implementation and a small memory footprint. For highly decentralized systems, the Training of Local Models from (Label) Counts (TLMC) algorithm is proposed. The method builds on LLPC, reducing communication by transferring only label counts for batches of observations between nodes. Feasibility of the approach is demonstrated by evaluating the algorithm's performance in the context of traffic flow prediction. It is shown that TLMC is much more communication-efficient than centralization of all data, but that accuracy can nevertheless compete with that of a centrally trained global model. Finally, a communication-efficient distributed algorithm for anomaly detection is proposed, the Vertically Distributed Core Vector Machine (VDCVM). It can be shown that the proposed algorithm communicates up to an order of magnitude less data during learning, in comparison to another state-of-the-art approach, or training a global model by the centralization of all data. Nevertheless, in many relevant cases, the VDCVM achieves similar or even higher accuracy on several controlled and benchmark datasets. A main result of the thesis is that communication-efficient learning is possible in cases where features from different nodes are conditionally independent, given the target value to be predicted. Most efficient are local models, which exchange label information between nodes. In comparison to consensus algorithms, which transmit labels repeatedly, TLMC sends labels only once between nodes. Communication could be even reduced further by learning from counts of labels. In the context of traffic flow prediction, the accuracy achieved is still sufficient in comparison to centralizing all data and training a global model. In the case of anomaly detection, similar results could be achieved by utilizing a sampling approach which draws only as many observations as needed to reach a (1+ε)-approximation of the minimum enclosing ball (MEB). The developed approaches have many applications in communication-constrained settings, in the sectors mentioned above. It has been shown that data can be reduced and learned from before it even enters the cloud. Decentralized processing might thus enable the analysis of big data masses, the more devices are getting connected to the IoT
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