251 research outputs found

    Supervised Transfer Learning for Product Information Question Answering

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    Popular e-commerce websites such as Amazon offer community question answering systems for users to pose product related questions and experienced customers may provide answers voluntarily. In this paper, we show that the large volume of existing community question answering data can be beneficial when building a system for answering questions related to product facts and specifications. Our experimental results demonstrate that the performance of a model for answering questions related to products listed in the Home Depot website can be improved by a large margin via a simple transfer learning technique from an existing large-scale Amazon community question answering dataset. Transfer learning can result in an increase of about 10% in accuracy in the experimental setting where we restrict the size of the data of the target task used for training. As an application of this work, we integrate the best performing model trained in this work into a mobile-based shopping assistant and show its usefulness.Comment: 2018 17th IEEE International Conference on Machine Learning and Application

    Optimal Beamforming for Physical Layer Security in MISO Wireless Networks

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    A wireless network of multiple transmitter-user pairs overheard by an eavesdropper, where the transmitters are equipped with multiple antennas while the users and eavesdropper are equipped with a single antenna, is considered. At different levels of wireless channel knowledge, the problem of interest is beamforming to optimize the users' quality-of-service (QoS) in terms of their secrecy throughputs or maximize the network's energy efficiency under users' QoS. All these problems are seen as very difficult optimization problems with many nonconvex constraints and nonlinear equality constraints in beamforming vectors. The paper develops path-following computational procedures of low-complexity and rapid convergence for the optimal beamforming solution. Their practicability is demonstrated through numerical examples

    Joint Power Allocation and Beamforming for Energy-Efficient Two-Way Multi-Relay Communications

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    © 2017 IEEE. This paper considers the joint design of user power allocation and relay beamforming in relaying communications, in which multiple pairs of single-antenna users exchange information with each other via multiple-antenna relays in two time slots. All users transmit their signals to the relays in the first time slot while the relays broadcast the beamformed signals to all users in the second time slot. The aim is to maximize the system's energy efficiency (EE) subject to quality-of-service (QoS) constraints in terms of exchange throughput requirements. The QoS constraints are nonconvex with many nonlinear cross-terms, so finding a feasible point is already computationally challenging. The sum throughput appears in the numerator while the total consumption power appears in the denominator of the EE objective function. The former is a nonconcave function and the latter is a nonconvex function, making fractional programming useless for EE optimization. Nevertheless, efficient iterations of low complexity to obtain its optimized solutions are developed. The performance of the multiple-user and multiple-relay networks under various scenarios is evaluated to show the merit of the proposed method

    Progressive Failure Simulation of Security Cable Barriers

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    Perimeter security cable barriers are widely used by various agencies all over the world to defeat threat vehicle penetration. New barrier designs require crash test validation prior to implementation. Full-scale vehicular crash tests are costly, whereas designs via finite element simulations are time consuming and require specialized skills. Based on full-scale crash tests, an innovative and simple algorithm has been developed to model the progressive failure of security cable barriers. A multi-body approach based on the first principles of physics was developed to substantially reduce computer runtime. The solution algorithm uses a large number of small time steps. Nonlinear vehicle and cable forces and deformations are calculated based on compatibility conditions. This methodology has been validated against three full-scale crash tests. This cable barrier model, displaying simulation results graphically in a time series, provides realistic response parameters of a security cable barrier design in less than 10 minutes of runtime with reasonable accuracy

    Conceptual Lanchester-type Decapitation Warfare Modelling

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    Decapitation operation has existed for a long time in military history; however, it was notuntil March 2003 'decapitation attack' became a well known term in the mass media. This paperis based on the connotation of decapitation based on historical study and refines the term intomilitary strategic concept of decapitation strategy. Ideas derived from detailed studies onLanchester-type combat models are used to describe the effectiveness of conventional regularforces under decapitation warfare, which includes asymmetric, nonlinear, stand-off and specialoperation forces (SOF) operations. A conceptual model is presented to describe the effects ofthe decapitation strategy on the regular battlefield. With extensive coverage of operational factorssuch as robustness of forces, time difference between combats, undermining effects, breakpoints,attrition rates, total force level and force allocation, the model is suitable to analyse complexscenario with different types of military operations consisting of decapitation strategy. Anillustrative example is provided to demonstrate the application of the model. The conceptualmodel is built based on hypotheses, assumptions, and criteria. In the absence of historical data,no data analysis and parameter estimation are involved

    High-resolution computed tomography illustrating pulmonary lymphangitic carcinomatosis in a patient with advanced pancreatic cancer: a case report

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    We present a case of advanced pancreatic cancer with diffuse pulmonary interstitial infiltrates and dyspnea in a 61-year-old Asian Taiwanese female. Although surgical lung biopsy is the diagnostic gold standard in most interstitial lung disease, it frequently leads to complications in sick patients. Based on the overall clinico-radiologic correlation, a diagnosis of pulmonary lymphangitic carcinomatosis was supported by the characteristic findings in high-resolution computed tomography
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