95 research outputs found

    Data Mining Models for Student Databases

    Get PDF

    Collaborative Planning and Event Monitoring Over Supply Chain Network

    Get PDF
    The shifting paradigm of supply chain management is manifesting increasing reliance on automated collaborative planning and event monitoring through information-bounded interaction across organizations. An end-to-end support for the course of actions is turning vital in faster incident response and proactive decision making. Many current platforms exhibit limitations to handle supply chain planning and monitoring in decentralized setting where participants may divide their responsibilities and share computational load of the solution generation. In this thesis, we investigate modeling and solution generation techniques for shared commodity delivery planning and event monitoring problems in a collaborative setting. In particular, we first elaborate a new model of Multi-Depot Vehicle Routing Problem (MDVRP) to jointly serve customer demands using multiple vehicles followed by a heuristic technique to search near-optimal solutions for such problem instances. Secondly, we propose two distributed mechanisms, namely: Passive Learning and Active Negotiation, to find near-optimal MDVRP solutions while executing the heuristic algorithm at the participant's side. Thirdly, we illustrate a collaboration mechanism to cost-effectively deploy execution monitors over supply chain network in order to collect in-field plan execution data. Finally, we describe a distributed approach to collaboratively monitor associations among recent events from an incoming stream of plan execution data. Experimental results over known datasets demonstrate the efficiency of the approaches to handle medium and large problem instances. The work has also produced considerable knowledge on the collaborative transportation planning and execution event monitoring

    Automatic Loop Tuning and Memory Management for Stencil Computations

    Get PDF
    The Texas Instruments C66x Digital Signal Processor (DSP) is an embedded processor technology that is targeted at real time signal processing. It is also developed with a high potential to become the new generation of coprocessor technology for high performance embedded computing. Of particular interest is its performance for stencil computations, such as those found in signal processing and computer vision tasks. A stencil is a loop in which the output value is updated at each position of an array by taking a weighted function of its neighbors. Efficiently mapping stencil-based kernels to the C66x device presents two challenges. The first one is how to efficiently optimize loops in order to facilitate the usage of Single Instruction Multiple Data (SIMD) instructions. On this architecture, like most others, SIMD instructions are not directly generated by the compiler. The second problem is how to manage on-chip memory in a way that minimizes off-chip memory access. Although this could theoretically be achieved by using a highly associative cache, the high rate of data reuse in stencil loops causes a high conflict miss rate. One way to solve this problem is to configure the on-chip memory as a program controlled scratchpad. It allows user to buffer a 2D block of data and minimizes the off-chip data access. For this dissertation, we have accomplished two goals: (1) Develop a methodology for optimization of arbitrary 2D stencils that fully utilize SIMD instructions through microachitecture-aware loop unrolling. (2) Deliver an easy-to-use scratchpad buffer management system and use it to improve the memory efficiency for 2D stencils. We show in the results and analysis section that our stencil compiler is able to achieve up to 2x speed up compared with the code generated by the industrial standard compiler developed by Texas Instruments, and our memory management system is able to achieve up to 10x speed up compared with cache

    Abduction and Anonymity in Data Mining

    Get PDF
    This thesis investigates two new research problems that arise in modern data mining: reasoning on data mining results, and privacy implication of data mining results. Most of the data mining algorithms rely on inductive techniques, trying to infer information that is generalized from the input data. But very often this inductive step on raw data is not enough to answer the user questions, and there is the need to process data again using other inference methods. In order to answer high level user needs such as explanation of results, we describe an environment able to perform abductive (hypothetical) reasoning, since often the solutions of such queries can be seen as the set of hypothesis that satisfy some requirements. By using cost-based abduction, we show how classification algorithms can be boosted by performing abductive reasoning over the data mining results, improving the quality of the output. Another growing research area in data mining is the one of privacy-preserving data mining. Due to the availability of large amounts of data, easily collected and stored via computer systems, new applications are emerging, but unfortunately privacy concerns make data mining unsuitable. We study the privacy implications of data mining in a mathematical and logical context, focusing on the anonymity of people whose data are analyzed. A formal theory on anonymity preserving data mining is given, together with a number of anonymity-preserving algorithms for pattern mining. The post-processing improvement on data mining results (w.r.t. utility and privacy) is the central focus of the problems we investigated in this thesis

    Innovation in manufacturing through digital technologies and applications: Thoughts and Reflections on Industry 4.0

    Get PDF
    The rapid pace of developments in digital technologies offers many opportunities to increase the efficiency, flexibility and sophistication of manufacturing processes; including the potential for easier customisation, lower volumes and rapid changeover of products within the same manufacturing cell or line. A number of initiatives on this theme have been proposed around the world to support national industries under names such as Industry 4.0 (Industrie 4.0 in Germany, Made-in-China in China and Made Smarter in the UK). This book presents an overview of the state of art and upcoming developments in digital technologies pertaining to manufacturing. The starting point is an introduction on Industry 4.0 and its potential for enhancing the manufacturing process. Later on moving to the design of smart (that is digitally driven) business processes which are going to rely on sensing of all relevant parameters, gathering, storing and processing the data from these sensors, using computing power and intelligence at the most appropriate points in the digital workflow including application of edge computing and parallel processing. A key component of this workflow is the application of Artificial Intelligence and particularly techniques in Machine Learning to derive actionable information from this data; be it real-time automated responses such as actuating transducers or informing human operators to follow specified standard operating procedures or providing management data for operational and strategic planning. Further consideration also needs to be given to the properties and behaviours of particular machines that are controlled and materials that are transformed during the manufacturing process and this is sometimes referred to as Operational Technology (OT) as opposed to IT. The digital capture of these properties and behaviours can then be used to define so-called Cyber Physical Systems. Given the power of these digital technologies it is of paramount importance that they operate safely and are not vulnerable to malicious interference. Industry 4.0 brings unprecedented cybersecurity challenges to manufacturing and the overall industrial sector and the case is made here that new codes of practice are needed for the combined Information Technology and Operational Technology worlds, but with a framework that should be native to Industry 4.0. Current computing technologies are also able to go in other directions than supporting the digital ‘sense to action’ process described above. One of these is to use digital technologies to enhance the ability of the human operators who are still essential within the manufacturing process. One such technology, that has recently become accessible for widespread adoption, is Augmented Reality, providing operators with real-time additional information in situ with the machines that they interact with in their workspace in a hands-free mode. Finally, two linked chapters discuss the specific application of digital technologies to High Pressure Die Casting (HDPC) of Magnesium components. Optimizing the HPDC process is a key task for increasing productivity and reducing defective parts and the first chapter provides an overview of the HPDC process with attention to the most common defects and their sources. It does this by first looking at real-time process control mechanisms, understanding the various process variables and assessing their impact on the end product quality. This understanding drives the choice of sensing methods and the associated smart digital workflow to allow real-time control and mitigation of variation in the identified variables. Also, data from this workflow can be captured and used for the design of optimised dies and associated processes

    Tracking the Temporal-Evolution of Supernova Bubbles in Numerical Simulations

    Get PDF
    The study of low-dimensional, noisy manifolds embedded in a higher dimensional space has been extremely useful in many applications, from the chemical analysis of multi-phase flows to simulations of galactic mergers. Building a probabilistic model of the manifolds has helped in describing their essential properties and how they vary in space. However, when the manifold is evolving through time, a joint spatio-temporal modelling is needed, in order to fully comprehend its nature. We propose a first-order Markovian process that propagates the spatial probabilistic model of a manifold at fixed time, to its adjacent temporal stages. The proposed methodology is demonstrated using a particle simulation of an interacting dwarf galaxy to describe the evolution of a cavity generated by a Supernov

    Acta Cybernetica : Volume 15. Number 2.

    Get PDF

    Utilizing AI/ML methods for measuring data quality

    Get PDF
    Kvalitní data jsou zásadní pro důvěryhodná rozhodnutí na datech založená. Značná část současných přístupů k měření kvality dat je spojena s náročnou, odbornou a časově náročnou prací, která vyžaduje manuální přístup k dosažení odpovídajících výsledků. Tyto přístupy jsou navíc náchylné k chybám a nevyužívají plně potenciál umělé inteligence (AI). Možným řešením je prozkoumat inovativní nové metody založené na strojovém učení (ML), které využívají potenciál AI k překonání těchto problémů. Významná část práce se zabývá teorií kvality dat, která poskytuje komplexní vhled do této oblasti. V existující literatuře byly objeveny čtyři moderní metody založené na ML a byla navržena jedna nová metoda založená na autoenkodéru (AE). Byly provedeny experimenty s AE a dolováním asociačních pravidel za pomoci metod zpracování přirozeného jazyka. Navrhované metody založené na AE prokázaly schopnost detekce potenciálních problémů s kvalitou dat na datasetech z reálného světa. Dolování asociačních pravidel dokázalo extrahovat byznys pravidla pro stanovený problém, ale vyžadovalo značné úsilí s předzpracováním dat. Alternativní metody nezaložené na AI byly také podrobeny analýze, ale vyžadovaly odborné znalosti daného problému a domény.High-quality data is crucial for trusted data-based decisions. A considerable part of current data quality measuring approaches is associated with expensive, expert and time-consuming work that includes manual effort to achieve adequate results. Furthermore, these approaches are prone to error and do not take full advantage of the AI potential. A possible solution is to explore ML-based state-of-the-art methods that are using the potential of AI to overcome these issues. A significant part of the thesis deals with data quality theory which provides a comprehensive insight into the field of data quality. Four ML-based state-of-the-art methods were discovered in the existing literature, and one novel method based on Autoencoders (AE) was proposed. Experiments with AE and Association Rule Mining using NLP were conducted. Proposed methods based on AE proved to detect potential data quality defects in real-world datasets. Association Rule Mining approach was able to extract business rules for a given business question, but the required significant preprocessing effort. Alternative non-AI methods were also analyzed but required reliance on expert and domain knowledge
    corecore