843 research outputs found

    Adaptive probability scheme for behaviour monitoring of the elderly using a specialised ambient device

    Get PDF
    A Hidden Markov Model (HMM) modified to work in combination with a Fuzzy System is utilised to determine the current behavioural state of the user from information obtained with specialised hardware. Due to the high dimensionality and not-linearly-separable nature of the Fuzzy System and the sensor data obtained with the hardware which informs the state decision, a new method is devised to update the HMM and replace the initial Fuzzy System such that subsequent state decisions are based on the most recent information. The resultant system first reduces the dimensionality of the original information by using a manifold representation in the high dimension which is unfolded in the lower dimension. The data is then linearly separable in the lower dimension where a simple linear classifier, such as the perceptron used here, is applied to determine the probability of the observations belonging to a state. Experiments using the new system verify its applicability in a real scenario

    Detection and Correction of Glitches in a Multiplexed Multichannel Data Stream—Application to the MADRAS Instrument

    Get PDF
    International audienceThis paper presents a new strategy to correct the Earth data corrupted by spurious samples that are randomly included in the multiplexed data stream provided by the MADRAS instrument. The proposed strategy relies on the construction of a trellis associated with each scan of the multichannel image, modeling the possible occurrences of these erroneous data. A specific weight that promotes the smooth behavior of the signals recorded in each channel is assigned to each transition between trellis states. The joint detection and correction of the erroneous data are conducted using a dynamic programming algorithm for minimizing the overall cost function throughout the trellis. Simulation results obtained on synthetic and real MADRAS data demonstrate the effectiveness of the proposed solution

    Detecting money laundering using hidden Markov model

    Get PDF
    Recent money laundering scandals, like the Danske Bank and Swedbank’s failure to mitigate money laundering risks (Kim, 2019), have made “anti money laundering” (AML) a much discussed topic. Governments are making AML regulations tougher and financial institutions are struggling to comply, one of the requirements is to actively monitor financial transactions to detect suspicious ones. Most of the financial industry applies simple rule-based methods for monitoring. This thesis provides a practical model to detect suspicious transactions using the hidden Markov model (HMM). The use of HMM is justified, because the criminal nature of a transaction is hidden to the financial institution, only transaction parameters can be observed. By using past data, a model is built to detect if current transaction is suspicious or not. The model is assessed with artificial and real transactions data. It was concluded that this model performs better than a classical k-means clustering algorithm

    A framework for real-time product quality monitoring system with consideration of process-induced variations

    Get PDF
    Department of Human and Systems EngineeringAs industrial technologies develop, the manufacturing industry is globally changing in more automated and complex manners, and the prediction of real-time product quality has become an essential issue. Although many of the physical manufacturing activities are getting more automated than ever, there still exist many uncovered parameters that, either directly or indirectly, affect the product quality. In many manufacturing sites, the quality tests in their processes still rely on few skilled operators and quality experts, which requires a lot of time and human efforts to manage the product quality issues. In this thesis, thus, a real-time/in-process quality monitoring system for small and medium size manufacturing environments is proposed to provide the data-driven product quality monitoring system framework. The proposed framework consists of a product quality ontology model for complex manufacturing supply chain environments, and a real-time quality prediction tool using the support vector machine (SVM) algorithm that enables the quality monitoring system to classify the product quality patterns from the in-process production data. Additionally, we propose a framework for analysis of the quality inspection results from the monitoring system with respect to quality costs, including inspection and warranty costs. In addition, this thesis establishes a relationship between the warranty cost and the severity of customer-perceived quality. Finally, we suggest a future work that a prescriptive product quality assessment concept using the Hidden Markov Models (HMM) that analyze and forecast possible future product quality problems using production data from manufacturing processes based on data flow analysis. Also, a door trim production data in an automotive company is illustrated to verify the proposed quality monitoring/prediction model.ope

    Cloud Service Selection System Approach based on QoS Model: A Systematic Review

    Get PDF
    The Internet of Things (IoT) has received a lot of interest from researchers recently. IoT is seen as a component of the Internet of Things, which will include billions of intelligent, talkative "things" in the coming decades. IoT is a diverse, multi-layer, wide-area network composed of a number of network links. The detection of services and on-demand supply are difficult in such networks, which are comprised of a variety of resource-limited devices. The growth of service computing-related fields will be aided by the development of new IoT services. Therefore, Cloud service composition provides significant services by integrating the single services. Because of the fast spread of cloud services and their different Quality of Service (QoS), identifying necessary tasks and putting together a service model that includes specific performance assurances has become a major technological problem that has caused widespread concern. Various strategies are used in the composition of services i.e., Clustering, Fuzzy, Deep Learning, Particle Swarm Optimization, Cuckoo Search Algorithm and so on. Researchers have made significant efforts in this field, and computational intelligence approaches are thought to be useful in tackling such challenges. Even though, no systematic research on this topic has been done with specific attention to computational intelligence. Therefore, this publication provides a thorough overview of QoS-aware web service composition, with QoS models and approaches to finding future aspects

    Performance modelling with adaptive hidden Markov models and discriminatory processor sharing queues

    Get PDF
    In modern computer systems, workload varies at different times and locations. It is important to model the performance of such systems via workload models that are both representative and efficient. For example, model-generated workloads represent realistic system behaviour, especially during peak times, when it is crucial to predict and address performance bottlenecks. In this thesis, we model performance, namely throughput and delay, using adaptive models and discrete queues. Hidden Markov models (HMMs) parsimoniously capture the correlation and burstiness of workloads with spatiotemporal characteristics. By adapting the batch training of standard HMMs to incremental learning, online HMMs act as benchmarks on workloads obtained from live systems (i.e. storage systems and financial markets) and reduce time complexity of the Baum-Welch algorithm. Similarly, by extending HMM capabilities to train on multiple traces simultaneously it follows that workloads of different types are modelled in parallel by a multi-input HMM. Typically, the HMM-generated traces verify the throughput and burstiness of the real data. Applications of adaptive HMMs include predicting user behaviour in social networks and performance-energy measurements in smartphone applications. Equally important is measuring system delay through response times. For example, workloads such as Internet traffic arriving at routers are affected by queueing delays. To meet quality of service needs, queueing delays must be minimised and, hence, it is important to model and predict such queueing delays in an efficient and cost-effective manner. Therefore, we propose a class of discrete, processor-sharing queues for approximating queueing delay as response time distributions, which represent service level agreements at specific spatiotemporal levels. We adapt discrete queues to model job arrivals with distributions given by a Markov-modulated Poisson process (MMPP) and served under discriminatory processor-sharing scheduling. Further, we propose a dynamic strategy of service allocation to minimise delays in UDP traffic flows whilst maximising a utility function.Open Acces

    Basic tasks of sentiment analysis

    Full text link
    Subjectivity detection is the task of identifying objective and subjective sentences. Objective sentences are those which do not exhibit any sentiment. So, it is desired for a sentiment analysis engine to find and separate the objective sentences for further analysis, e.g., polarity detection. In subjective sentences, opinions can often be expressed on one or multiple topics. Aspect extraction is a subtask of sentiment analysis that consists in identifying opinion targets in opinionated text, i.e., in detecting the specific aspects of a product or service the opinion holder is either praising or complaining about

    Sequential Protocols’ Behaviour Analysis

    Get PDF
    The growing adoption of the Session Initiation Protocol (SIP) has motivated the development of tools capable of detecting valid SIP dialogues, in order to potentially identify behavioural traits of the protocol. This thesis serves as a starting point for characterising SIP dialogues, in terms of distinct signalling sequences, and providing a reliable classification of SIP sequences. We start by analysing sequential pattern mining algorithms in an off-line manner, providing valuable statistical information regarding the SIP sequences. In this analysis some classical Sequential Pattern Mining algorithms are evaluated, to gather insights on resource consumption and computation time. The results of the analysis lead to the identification of every possible combinations of a given SIP sequence in a fast manner. In the second stage of this work we study different stochastic tools to classify the SIP dialogues according to the observed SIP messages. Deviations to previously observed SIP dialogues are also identified. Some experimental results are presented, which adopt the Hidden Markov Model jointly used with the Viterbi algorithm to classify multiple SIP messages that are observed sequentially. The experimental tests include a stochastic dynamic evaluation, and the assessment of the stochastic similarity. The goal of these tests is to show the reliability and robustness of the algorithms adopted to classify the incoming SIP sequences, and thus characterizing the SIP dialogues
    • 

    corecore