27,108 research outputs found

    Strong laws of large numbers for sub-linear expectations

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    We investigate three kinds of strong laws of large numbers for capacities with a new notion of independently and identically distributed (IID) random variables for sub-linear expectations initiated by Peng. It turns out that these theorems are natural and fairly neat extensions of the classical Kolmogorov's strong law of large numbers to the case where probability measures are no longer additive. An important feature of these strong laws of large numbers is to provide a frequentist perspective on capacities.Comment: 10 page

    Querying Streaming System Monitoring Data for Enterprise System Anomaly Detection

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    The need for countering Advanced Persistent Threat (APT) attacks has led to the solutions that ubiquitously monitor system activities in each enterprise host, and perform timely abnormal system behavior detection over the stream of monitoring data. However, existing stream-based solutions lack explicit language constructs for expressing anomaly models that capture abnormal system behaviors, thus facing challenges in incorporating expert knowledge to perform timely anomaly detection over the large-scale monitoring data. To address these limitations, we build SAQL, a novel stream-based query system that takes as input, a real-time event feed aggregated from multiple hosts in an enterprise, and provides an anomaly query engine that queries the event feed to identify abnormal behaviors based on the specified anomaly models. SAQL provides a domain-specific query language, Stream-based Anomaly Query Language (SAQL), that uniquely integrates critical primitives for expressing major types of anomaly models. In the demo, we aim to show the complete usage scenario of SAQL by (1) performing an APT attack in a controlled environment, and (2) using SAQL to detect the abnormal behaviors in real time by querying the collected stream of system monitoring data that contains the attack traces. The audience will have the option to interact with the system and detect the attack footprints in real time via issuing queries and checking the query results through a command-line UI.Comment: Accepted paper at ICDE 2020 demonstrations track. arXiv admin note: text overlap with arXiv:1806.0933

    Review of morphology dependent charge carrier mobility in MEH-PPV

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    Charge carrier mobility in poly(2-methoxy,5(2'-ethyl-hexyloxy)-p-phenylene vinylene) (MEH-PPV) films were measured as a function of temperature and electric field parallel and perpendicular to the substrate for devices prepared from different solvents and under different processing conditions Bulk structural morphology was characterized by various X-ray diffraction measurements such as wide angle, small angle and X-ray reflection. Surface morphology was characterized using various scanning probe microscopic techniques Mobilities were found to follow Gaussian disorder model (GDM) and to be highly anisotropic not only depending on the solvents used but also on the film preparation method such as spin-coating or drop-casting While no direct correlation was found between charge carrier mobility and photoluminescence, charge transport parameters were correlated with structural morpholog

    Exploring SCM awareness in Chinese SOEs: insights from a case study

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    Supply chain management (SCM) systems have been used by modern enterprises to support and management the links of supply chain from suppliers to customers. This paper aimed to investigate the current situation of SCM adoption in Chinese state-owned enterprises (SOEs), especially in a geographically dispersed SOE group using a case study approach. Questionnaires were selected as the data collection method in the research. The questionnaire findings show although a set of SCM related functional information systems including purchasing systems, manufacturing and production systems, finance and accounting systems have been applied in Chinese SOEs, an integrated enterprise-wide SCM system is currently missing. Therefore, due to the size and national impact of the SOE in question, it is strongly suggested that an integrated and homogeneous approach to SCM should be adopted in order to improve efficiency, productivity and core competitiveness of this type of organization
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