180 research outputs found

    The US fashion industry: A supply chain review

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    Cataloged from PDF version of article.The fashion industry has short product life cycles, tremendous product variety, volatile and unpredictable demand, and long and inflexible supply processes. These characteristics, a complex supply chain and wide availability of data make the industry a suitable avenue for efficient supply chain management practices. The industry has also been in a transition over the last 20 years: significant consolidation in retail, majority of apparel manufacturing operations moving overseas and, more recently, increasing use of electronic commerce in retail and wholesale trade. This paper aims to review the current state of operations and recent trends across the fashion supply chain in the US. We use industry-wide data, articles from business journals, industry reviews and extensive interviews with an apparel manufacturer in California, and a major US department store chain to describe the current operational practices and how the industry is restructuring itself during the transition, focusing at the apparel manufacture and retail segments of the supply chain. 2008 Elsevier B.V. All rights reserved

    Hybrid Data Race Detection for Multicore Software

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    Multithreaded programs are prone to concurrency errors such as deadlocks, race conditions and atomicity violations. These errors are notoriously difficult to detect due to the non-deterministic nature of concurrent software running on multicore hardware. Data races result from the concurrent access of shared data by multiple threads and can result in unexpected program behaviors. Main dynamic data race detection techniques in the literature are happens-before and lockset algorithms which suffer from high execution time and memory overhead, miss many data races or produce a high number of false alarms. Our goal is to improve the performance of dynamic data race detection, while at the same time improving its accuracy by generating fewer false alarms. We develop a hybrid data race detection algorithm that is a combination of the happens-before and lockset algorithms in a tool. Rather than focusing on individual memory accesses by each thread, we focus on sequence of memory accesses by each thread, called a segment. This allows us to improve the performance of data race detection. We implement several optimizations on our hybrid data race detector and compare our technique with traditional happens-before and lockset detectors. The experiments are performed with C/C++ multithreaded benchmarks using Pthreads library from PARSEC suite and large applications such as Apache web server. Our experiments showed that our hybrid detector is 15 % faster than the happens-before detector and produces 50 % less potential data races than the lockset detector. Ultimately, a hybrid data race detector can improve the performance and accuracy of data race detection, enhancing its usability in practice

    Importance-Driven Deep Learning System Testing

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    Deep Learning (DL) systems are key enablers for engineering intelligent applications due to their ability to solve complex tasks such as image recognition and machine translation. Nevertheless, using DL systems in safety- and security-critical applications requires to provide testing evidence for their dependable operation. Recent research in this direction focuses on adapting testing criteria from traditional software engineering as a means of increasing confidence for their correct behaviour. However, they are inadequate in capturing the intrinsic properties exhibited by these systems. We bridge this gap by introducing DeepImportance, a systematic testing methodology accompanied by an Importance-Driven (IDC) test adequacy criterion for DL systems. Applying IDC enables to establish a layer-wise functional understanding of the importance of DL system components and use this information to guide the generation of semantically-diverse test sets. Our empirical evaluation on several DL systems, across multiple DL datasets and with state-of-the-art adversarial generation techniques demonstrates the usefulness and effectiveness of DeepImportance and its ability to guide the engineering of more robust DL systems

    A New Algorithm for Cartographic Simplification of Streams and Lakes Using Deviation Angles and Error Bands

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    Multi-representation databases (MRDBs) are used in several geographical information system applications for different purposes. MRDBs are mainly obtained through model and cartographic generalizations. Simplification is the essential operator of cartographic generalization, and streams and lakes are essential features in hydrography. In this study, a new algorithm was developed for the simplification of streams and lakes. In this algorithm, deviation angles and error bands are used to determine the characteristic vertices and the planimetric accuracy of the features, respectively. The algorithm was tested using a high-resolution national hydrography dataset of Pomme de Terre, a sub-basin in the USA. To assess the performance of the new algorithm, the Bend Simplify and Douglas-Peucker algorithms, the medium-resolution hydrography dataset of the sub-basin, and Topfer's radical law were used. For quantitative analysis, the vertex numbers, the lengths, and the sinuosity values were computed. Consequently, it was shown that the new algorithm was able to meet the main requirements (i.e., accuracy, legibility and aesthetics, and storage)

    Evolutionary optimization of a charge transfer ionic potential model for Ta/Ta-oxide hetero-interfaces

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    Tantalum, tantalum oxide and their hetero-interfaces are of tremendous technological interest in several applications spanning electronics, thermal management, catalysis and biochemistry. For example, local oxygen stoichiometry variation in TaOx memristors comprising of metallic (Ta) and insulating oxide (Ta2O5) have been shown to result in fast switching on the sub-nanosecond timescale over a billion cycles, relevant to neuromorphic computation. Despite its broad importance, an atomistic scale understanding of oxygen stoichiometry variation across Ta/TaOx hetero-interfaces, such as during early stages of oxidation and oxide growth, is not well understood. This is mainly due to the lack of a variable charge interatomic potential model for tantalum oxides that can accurately describe the ionic interactions in the metallic (Ta) and oxide (TaOx) environment as well as at their interfaces. To address this challenge, we introduce a charge transfer ionic potential (CTIP) model for Ta/Ta-oxide system by training against lattice parameters, cohesive energies, equations of state, and elastic properties of various experimentally observed Ta2O5 polymorphs. The best set of CTIP parameters are determined by employing a single-objective global optimization scheme driven by genetic algorithms followed by local Simplex optimization. Our newly developed CTIP potential accurately predicts structure, thermodynamics, energetic ordering of polymorphs, as well as elastic and surface properties of both Ta and Ta2O5, in excellent agreement with DFT calculations and experiments. We employ our newly parameterized CTIP potential to investigate the early stages of oxidation of Ta at different temperatures and atomic/molecular nature of the oxidizing species
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