1,306 research outputs found

    MadSGM: Multivariate Anomaly Detection with Score-based Generative Models

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    The time-series anomaly detection is one of the most fundamental tasks for time-series. Unlike the time-series forecasting and classification, the time-series anomaly detection typically requires unsupervised (or self-supervised) training since collecting and labeling anomalous observations are difficult. In addition, most existing methods resort to limited forms of anomaly measurements and therefore, it is not clear whether they are optimal in all circumstances. To this end, we present a multivariate time-series anomaly detector based on score-based generative models, called MadSGM, which considers the broadest ever set of anomaly measurement factors: i) reconstruction-based, ii) density-based, and iii) gradient-based anomaly measurements. We also design a conditional score network and its denoising score matching loss for the time-series anomaly detection. Experiments on five real-world benchmark datasets illustrate that MadSGM achieves the most robust and accurate predictions

    Lateral Hopping of CO on Ag(110) by Multiple Overtone Excitation

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    A novel type of action spectrum representing multiple overtone excitations of the upsilon(M-C) mode was observed for lateral hopping of a CO molecule on Ag(110) induced by inelastically tunneled electrons from the tip of a scanning tunneling microscope. The yield of CO hopping shows sharp increases at 261 +/- 4 mV, corresponding to the C-O internal stretching mode, and at 61 +/- 2, 90 +/- 2, and 148 +/- 7 mV, even in the absence of corresponding fundamental vibrational modes. The mechanism of lateral CO hopping on Ag (110) was explained by the multistep excitation of overtone modes of upsilon(M-C) based on the numerical fitting of the action spectra, the nonlinear dependence of the hopping rate on the tunneling current, and the hopping barrier obtained from thermal diffusion experiments.ope

    A transition process from information systems acceptance to infusion behaviour in online brand communities : a socialization process perspective

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    Social media such as Facebook, Youtube, Twitter, and online communities plays an important role for knowledge production and diffusion as well as discussions among people. Among social media, online brand communities (OBCs) have recently received attention from both academics and practitioners due to the practical benefits of OBCs for consumers and companies. For consumers, knowledge sharing and its collective activities help them to make purchase decisions and to protect themselves against firms’ monopoly and oligopoly or collusion and anticompetitive actions. For companies, new ideas and feedback on brand products created by OBC members are useful input to develop new products and enhance existing product lines. Therefore, active content generation by community members is one of the critical success factors of OBCs. However, many scholars argue that only a few members who are more devoted to a community are tending to engage in OBC activities and many community members tend to remain in the periphery (sometimes called ‘lurkers') of the community by using OBCs merely for gathering information without any contributions. Therefore, it is important to make members in the periphery of the community transit to the core to increase members’ intentions and ‘devoted members’ to produce more valuable benefits for both consumers and firms. In spite of its importance, the literature is lacking in efforts to explain how and when community members in the periphery transit to the core of the community in a long-term perspective. This study aims to reveal how and why OBC members transit from the periphery to the core of the community and how to increase their intention to use OBC from a long-term perspective. OBC use behaviour is classified into, largely, two categories according to the purposes of an OBC: behaviour with a brand product consumption purpose; and behaviour with a social relationship building purpose. This study classifies OBC members as three clusters by social identity theory: tourists, minglers, and devoted members (devotees and insiders). The devoted members have valuable consumption knowledge of brand and strong social bonds in the OBC and the OBC members become a devoted member by accumulated brand knowledge and experiences through long-term OBC use. Therefore, from a socialisation aspect, this study adopts organisational socialisation theory as the theoretical lens to explain how and why the members evolve from novice members as tourist to devoted members in OBC contexts. Socialisation theories argue that there are usually three sequential stages for a member to gain full membership in a community: pre-entry, accommodation, and affiliation. In addition, this study adopts IS implementation theory to understand OBC user behaviours from an IS use behaviour perspective: acceptance in the pre-entry stage and routinisation in the accommodation stage and infusion in the affiliation stage. By reviewing socialisation theory and IS implementation theory, this study finds four significant motivations, those of information quality, trust, sense of belonging, and brand loyalty for intention of OBC use from the acceptance (pre-entry) to infusion (affiliation) stages. To integrate the socialisation perspective with the IS use perspective, this study adopts a technology acceptance model (TAM) as a theoretical framework to link to motivators in different OBC use behaviour from the acceptance to infusion stages. As a result, this study proposes a conceptual framework to explain the OBC members’ transition process from acceptance (pre-entry) to infusion (affiliation). The aim of this study is to predict and explain the transition of motivators for OBC use from pre-entry to affiliation and how to improve members’ intention of OBC use from a long-term perspective ultimately to foster ‘devoted members’. This study adopts an online survey targeting 518 participants who belong to 17 OBCs in South Korea and the conceptual framework is validated. The results show that all factors (i.e. information quality, trust, sense of belonging, brand loyalty) are significant determinants to increase intention to use OBCs and the factors have a causal relationship with each other to form a transition process from the acceptance (pre-entry) to infusion (affiliation) stages. This study also reveals that brand loyalty has a significant role to explain the transition process and directly influence user intention to use OBCs. The sense of belonging also directly affects members’ intention to use OBCs but has less impact than brand loyalty. In addition, the results indicate that TAM is an appropriate model to predict user behaviours in a long-term perspective to explain the change of OBC use behaviour from the acceptance to infusion stage and confirms that perceived usefulness and perceived ease of use have significant impact on the intention to use OBCs as in other IS studies. Understanding the transition process within OBCs has theoretical and practical implications. Theoretically, it will extend our understanding of how IS end users transit from acceptance behaviour to continued use and extended use of information systems in virtual community contexts. For managers, this study will provide them with insight on how to retain potential consumers in OBCs and facilitate their activities to gain consumer feedback on existing and new products.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Designing for Effective and Safe Multidisciplinary Primary Care Teamwork: Using the Time of COVID-19 as a Case Study

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    Effective medical teamwork can improve the effectiveness and experience of care for staff and patients, including safety. Healthcare organizations, and especially primary care clinics, have sought to improve medical teamwork through improved layout and design, moving staff into shared multidisciplinary team rooms. While co-locating staff has been shown to increase communi-cation, successful designs balance four teamwork needs: face-to-face communications; situational awareness; heads-down work; perception of teamness. However, precautions for COVID-19 make it more difficult to conduct face-to-face communications. In this paper we describe a model for un-derstanding how layout affects these four teamwork needs and describe how the perception of teamwork by staff changed after COVID-19 precautions were put in place. Observations, interviews and two standard surveys were conducted in two primary care clinics before COVID-19 and again in 2021 after a year of precautions. In general, staff felt more isolated and found it more difficult to conduct brief consults, though these perceptions varied by role. RNs, who spent more time on the phone, found it convenient to work part time-from home, while medical assistants found it more difficult to find providers in the distanced clinics. These cases suggest some important considera-tions for future clinic designs, including greater physical transparency that also allow for physical separation and more spaces for informal communication that are distanced from workstations
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