435,466 research outputs found

    Detecting anomalous longitudinal associations through higher order mining

    Get PDF
    The detection of unusual or anomalous data is an important function in automated data analysis or data mining. However, the diversity of anomaly detection algorithms shows that it is often difficult to determine which algorithms might detect anomalies given any random dataset. In this paper we provide a partial solution to this problem by elevating the search for anomalous data in transaction-oriented datasets to an inspection of the rules that can be produced by higher order longitudinal/spatio-temporal association rule mining. In this way we are able to apply algorithms that may provide a view of anomalies that is arguably closer to that sought by information analysts.Sydney, NS

    Integration of Temporal Abstraction and Dynamic Bayesian Networks in Clinical Systems. A preliminary approach

    Get PDF
    Abstraction of temporal data (TA) aims to abstract time-points into higher-level interval concepts and to detect significant trends in both low-level data and abstract concepts. TA methods are used for summarizing and interpreting clinical data. Dynamic Bayesian Networks (DBNs) are temporal probabilistic graphical models which can be used to represent knowledge about uncertain temporal relationships between events and state changes during time. In clinical systems, they were introduced to encode and use the domain knowledge acquired from human experts to perform decision support. A hypothesis that this study plans to investigate is whether temporal abstraction methods can be effectively integrated with DBNs in the context of medical decision-support systems. A preliminary approach is presented where a DBN model is constructed for prognosis of the risk for coronary artery disease (CAD) based on its risk factors and using as test bed a dataset that was collected after monitoring patients who had positive history of cardiovascular disease. The technical objectives of this study are to examine how DBNs will represent the abstracted data in order to construct the prognostic model and whether the retrieved rules from the model can be used for generating more complex abstractions

    Conceptual word order principles and Mandarin Chinese grammar

    Get PDF
    Research on iconicity and word order in Mandarin Chinese (henceforth MC) investigates the correlation between the sequence of linguistic elements in the sentence and the temporal, spatial, and causal characteristics of the events they describe. Such correlations are captured through a number of organizational principles, generally referred to in the literature as conceptual or cognitive word order principles. Among the most significant principles are the principle of temporal sequence, the principle of temporal scope and that of whole-before-part. Conceptual principles are of great interest for several reasons: first, they exhibit an iconic nature and show how and to what extent MC word order (henceforth WO) mirrors both universal and culture-specific conceptualizations of space, time and cause-effect logical relations. As such, they are easy to understand and remember, thus providing interesting applications to MC language instruction. Moreover, according to Tai (1985, 1989, 1993), Ho (1993), Hu (1995) and Loar (2011) among others, such principles bear great explanatory power in that they underlie several seemingly unrelated syntactic patterns and constructions. This chapter provides an introduction to organizational principles underlying MC word order, with a specific focus on conceptual (or cognitive) principles, such as the Principle of Temporal Sequence (PTS) and that of Whole-Before- Part (WBP). Specifically, it presents (i) the theoretical approach they are grounded in, (ii) their potential in language description, as compared to grammatical rules, and (iii) their applications to language acquisition and discourse analysis. These principles are shown to operate both at the micro-levels of phrase and clause and at higher levels of discourse and text. The discussion avails itself of natural language in use; unless otherwise specified, all examples are drawn from corpora, such as the PKU corpus of Modern Mandarin Chinese, Peking University or Ho’s corpus of spontaneous spoken texts (Ho 1993: 14-6)

    Runtime verification for biochemical programs

    Get PDF
    The biochemical paradigm is well-suited for modelling autonomous systems and new programming languages are emerging from this approach. However, in order to validate such programs, we need to define precisely their semantics and to provide verification techniques. In this paper, we consider a higher-order biochemical calculus that models the structure of system states and its dynamics thanks to rewriting abstractions, namely rules and strategies. We extend this calculus with a runtime verification technique in order to perform automatic discovery of property satisfaction failure. The property specification language is a subclass of LTL safety and liveness properties

    Identification of the neighborhood and CA rules from spatio-temporal CA patterns

    Get PDF
    Extracting the rules from spatio-temporal patterns generated by the evolution of cellular automata (CA) usually produces a CA rule table without providing a clear understanding of the structure of the neighborhood or the CA rule. In this paper, a new identification method based on using a modified orthogonal least squares or CA-OLS algorithm to detect the neighborhood structure and the underlying polynomial form of the CA rules is proposed. The Quine-McCluskey method is then applied to extract minimum Boolean expressions from the polynomials. Spatio-temporal patterns produced by the evolution of 1D, 2D, and higher dimensional binary CAs are used to illustrate the new algorithm, and simulation results show that the CA-OLS algorithm can quickly select both the correct neighborhood structure and the corresponding rule

    Multiple-F0 estimation of piano sounds exploiting spectral structure and temporal evolution

    Get PDF
    This paper proposes a system for multiple fundamental frequency estimation of piano sounds using pitch candidate selection rules which employ spectral structure and temporal evolution. As a time-frequency representation, the Resonator Time-Frequency Image of the input signal is employed, a noise suppression model is used, and a spectral whitening procedure is performed. In addition, a spectral flux-based onset detector is employed in order to select the steady-state region of the produced sound. In the multiple-F0 estimation stage, tuning and inharmonicity parameters are extracted and a pitch salience function is proposed. Pitch presence tests are performed utilizing information from the spectral structure of pitch candidates, aiming to suppress errors occurring at multiples and sub-multiples of the true pitches. A novel feature for the estimation of harmonically related pitches is proposed, based on the common amplitude modulation assumption. Experiments are performed on the MAPS database using 8784 piano samples of classical, jazz, and random chords with polyphony levels between 1 and 6. The proposed system is computationally inexpensive, being able to perform multiple-F0 estimation experiments in realtime. Experimental results indicate that the proposed system outperforms state-of-the-art approaches for the aforementioned task in a statistically significant manner. Index Terms: multiple-F0 estimation, resonator timefrequency image, common amplitude modulatio

    Method For Detecting Shilling Attacks In E-commerce Systems Using Weighted Temporal Rules

    Full text link
    The problem of shilling attacks detecting in e-commerce systems is considered. The purpose of such attacks is to artificially change the rating of individual goods or services by users in order to increase their sales. A method for detecting shilling attacks based on a comparison of weighted temporal rules for the processes of selecting objects with explicit and implicit feedback from users is proposed. Implicit dependencies are specified through the purchase of goods and services. Explicit feedback is formed through the ratings of these products. The temporal rules are used to describe hidden relationships between the choices of user groups at two consecutive time intervals. The method includes the construction of temporal rules for explicit and implicit feedback, their comparison, as well as the formation of an ordered subset of temporal rules that capture potential shilling attacks. The method imposes restrictions on the input data on sales and ratings, which must be ordered by time or have timestamps. This method can be used in combination with other approaches to detecting shilling attacks. Integration of approaches allows to refine and supplement the existing attack patterns, taking into account the latest changes in user priorities

    Verifying Temporal Properties of Reactive Systems by Transformation

    Full text link
    We show how program transformation techniques can be used for the verification of both safety and liveness properties of reactive systems. In particular, we show how the program transformation technique distillation can be used to transform reactive systems specified in a functional language into a simplified form that can subsequently be analysed to verify temporal properties of the systems. Example systems which are intended to model mutual exclusion are analysed using these techniques with respect to both safety (mutual exclusion) and liveness (non-starvation), with the errors they contain being correctly identified.Comment: In Proceedings VPT 2015, arXiv:1512.02215. This work was supported, in part, by Science Foundation Ireland grant 10/CE/I1855 to Lero - the Irish Software Engineering Research Centre (www.lero.ie), and by the School of Computing, Dublin City Universit
    • …
    corecore