6,204 research outputs found

    Effect of waterlogging on boreal forest tree seedlings during dormancy and early growing season

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    2016Diss. : Itä-Suomen yliopisto, 201

    Self-Learning Hot Data Prediction: Where Echo State Network Meets NAND Flash Memories

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    © 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Well understanding the access behavior of hot data is significant for NAND flash memory due to its crucial impact on the efficiency of garbage collection (GC) and wear leveling (WL), which respectively dominate the performance and life span of SSD. Generally, both GC and WL rely greatly on the recognition accuracy of hot data identification (HDI). However, in this paper, the first time we propose a novel concept of hot data prediction (HDP), where the conventional HDI becomes unnecessary. First, we develop a hybrid optimized echo state network (HOESN), where sufficiently unbiased and continuously shrunk output weights are learnt by a sparse regression based on L2 and L1/2 regularization. Second, quantum-behaved particle swarm optimization (QPSO) is employed to compute reservoir parameters (i.e., global scaling factor, reservoir size, scaling coefficient and sparsity degree) for further improving prediction accuracy and reliability. Third, in the test on a chaotic benchmark (Rossler), the HOESN performs better than those of six recent state-of-the-art methods. Finally, simulation results about six typical metrics tested on five real disk workloads and on-chip experiment outcomes verified from an actual SSD prototype indicate that our HOESN-based HDP can reliably promote the access performance and endurance of NAND flash memories.Peer reviewe

    Surface Defect Classification for Hot-Rolled Steel Strips by Selectively Dominant Local Binary Patterns

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    Developments in defect descriptors and computer vision-based algorithms for automatic optical inspection (AOI) allows for further development in image-based measurements. Defect classification is a vital part of an optical-imaging-based surface quality measuring instrument. The high-speed production rhythm of hot continuous rolling requires an ultra-rapid response to every component as well as algorithms in AOI instrument. In this paper, a simple, fast, yet robust texture descriptor, namely selectively dominant local binary patterns (SDLBPs), is proposed for defect classification. First, an intelligent searching algorithm with a quantitative thresholding mechanism is built to excavate the dominant non-uniform patterns (DNUPs). Second, two convertible schemes of pattern code mapping are developed for binary encoding of all uniform patterns and DNUPs. Third, feature extraction is carried out under SDLBP framework. Finally, an adaptive region weighting method is built for further strengthening the original nearest neighbor classifier in the feature matching stage. The extensive experiments carried out on an open texture database (Outex) and an actual surface defect database (Dragon) indicates that our proposed SDLBP yields promising performance on both classification accuracy and time efficiencyPeer reviewe

    A Novel Risk Assessment Model for Prefabricated Building Construction Based on Combination Weight and Catastrophe Progression Method

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    To reduce the construction risk of prefabricated building projects, a prefabricated building construction risk assessment index system with five first-level indicators and 21 second-level indicators was established based on human, machine, material, management, and environmental factors. By combining the analytic hierarchy process (AHP), CRiteria Importance through Intercriteria Correlation (CRITIC), and catastrophe theory, a risk assessment model of prefabricated building construction based on a combination weighting and catastrophe progression method was constructed. The effectiveness of the assessment model using the combination weighting and catastrophe progression method was verified through case analysis. The results show the following: (1) The quality of the prefabricated components, the standardization degree of the prefabricated components, and the environment of the installation working space in the construction risk assessment indicators of prefabricated buildings obtained by the AHP-CRITIC weighting method have higher weights. (2) Four prefabricated construction enterprises under China State Construction Corporation are evaluated, and the evaluation results effectively evaluate the project risk situation before an accident occurred, achieving the goal of improving the risk management efficiency. (3) The AHP-CRITIC weighting method can reflect the fuzziness of the construction risk of the evaluated project, effectively reduce information loss, and thus make the evaluation results more accurate. The conclusions have important practical significance for improving the construction risk management of prefabricated buildings

    A Novel Chaotic Particle Swarm Optimization Algorithm for Parking Space Guidance

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    An evolutionary approach of parking space guidance based upon a novel Chaotic Particle Swarm Optimization (CPSO) algorithm is proposed. In the newly proposed CPSO algorithm, the chaotic dynamics is combined into the position updating rules of Particle Swarm Optimization to improve the diversity of solutions and to avoid being trapped in the local optima. This novel approach, that combines the strengths of Particle Swarm Optimization and chaotic dynamics, is then applied into the route optimization (RO) problem of parking lots, which is an important issue in the management systems of large-scale parking lots. It is used to find out the optimized paths between any source and destination nodes in the route network. Route optimization problems based on real parking lots are introduced for analyzing and the effectiveness and practicability of this novel optimization algorithm for parking space guidance have been verified through the application results
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