3,232 research outputs found

    Chinese and North American Culture: a New Perspective in Linguistics Studies

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    We explored the two cultures in the two countries. There has been discussed on Chinese culture and North American culture. Chinese language, ceramics, architecture, music, dance, literature, martial arts, cuisine, visual arts, philosophy, business etiquette, religion, politics, and history have global influence, while its traditions and festivals are also celebrated, instilled, and practiced by people around the world. The culture of North America refers to the arts and other manifestations of human activities and achievements from the continent of North America. The American way of life or simply the American way is the unique lifestyle of the people of the United States of America. It refers to a nationalist ethos that adheres to the principle of life, liberty and the pursuit of happiness

    Towards Robust Neural Networks via Random Self-ensemble

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    Recent studies have revealed the vulnerability of deep neural networks: A small adversarial perturbation that is imperceptible to human can easily make a well-trained deep neural network misclassify. This makes it unsafe to apply neural networks in security-critical applications. In this paper, we propose a new defense algorithm called Random Self-Ensemble (RSE) by combining two important concepts: {\bf randomness} and {\bf ensemble}. To protect a targeted model, RSE adds random noise layers to the neural network to prevent the strong gradient-based attacks, and ensembles the prediction over random noises to stabilize the performance. We show that our algorithm is equivalent to ensemble an infinite number of noisy models fϵf_\epsilon without any additional memory overhead, and the proposed training procedure based on noisy stochastic gradient descent can ensure the ensemble model has a good predictive capability. Our algorithm significantly outperforms previous defense techniques on real data sets. For instance, on CIFAR-10 with VGG network (which has 92\% accuracy without any attack), under the strong C\&W attack within a certain distortion tolerance, the accuracy of unprotected model drops to less than 10\%, the best previous defense technique has 48%48\% accuracy, while our method still has 86%86\% prediction accuracy under the same level of attack. Finally, our method is simple and easy to integrate into any neural network.Comment: ECCV 2018 camera read

    Measuring and Correcting Response Heaping Arising From the Use of Prototypes

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    Imprecision in respondent recall can cause response heaping in frequency data for particular values (e.g., 5, 10, 15). In human dimensions research, heaping can occur for variables such as days of participation (e.g., hunting, fishing), animals/fish harvested, or money spent on licenses. Distributions with heaps can bias population estimates because the means and totals can be inflated or deflated. Because bias can result in poor management decisions, determining if the bias is large enough to matter is important. This note introduces the logic and flow of a deheaping program that estimates bias in means and totals when people use approximate responses (i.e., prototypes). The program can make estimates even when spikes occur due to bag limits. The program is available online, and smooths heaps at multiples of 5 (numbers ending in 5 and 0) and 7 (e.g., 7, 14, 21), and produces standard deviations in estimates

    Applicability Of Continuum Fracture Mechanics In Atomistic Systems

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    By quantitating the amplitude of the unbounded stress, the continuum fracture mechanics defines the stress intensity factor K to characterize the stress and displacement fields in the vicinity of the crack tip, thereby developing the relation between the stress singularity and surface energy (energy release rate G). This G-K relation, assigning physical meaning to the stress intensity factor, makes these two fracture parameters widely used in predicting the onset of crack propagation. However, due to the discrete nature of the atomistic structures without stress singularity, there might be discrepancy between the failure prediction and the reality of nanostructured materials. Defining the local atomistic stress with convergence within one lattice ensures the near-tip stress in the discrete systems displays the detailed stress concentration. Through comparison to the equivalent continuum finite element models, although these atomistic near-tip stress distributions preserve the trend of inverse square root singularity, the corresponding fracture toughness in terms of critical stress intensity factor (or energy release rate) is size dependent (i.e., varying with the size of the singular stress zone, K-dominance zone). Consequently, the failure load predicted by constant fracture toughness deviates from what a nanostructure can sustain if the singular stress is not dominant. The two-parameter model, including the contributions from both singular and non-singular terms, is utilized to improve the inadequacy of continuum fracture mechanics. On the other hand, since the magnitude of the atomistic near-tip stress is finite, the maximum stress criterion is valid in atomistic systems, proven by the close match between the peak stress and the theoretic strength under the failure condition. Furthermore, the surface energy determined by the overall energy balance over the crack growth within several sizes of lattice constant is shown to be size-independent, in contrast to the size-dependent results obtained by the G-K relatio

    Optimization on fresh outdoor air ratio of air conditioning system with stratum ventilation for both targeted indoor air quality and maximal energy saving

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    Stratum ventilation can energy efficiently provide good inhaled indoor air quality with a proper operation (e.g., fresh outdoor air ratio). However, the non-uniform CO2 distribution in a stratum-ventilated room challenges the provision of targeted indoor air quality. This study proposes an optimization on the fresh outdoor air ratio of stratum ventilation for both the targeted indoor air quality and maximal energy saving. A model of CO2 concentration in the breathing zone is developed by coupling CO2 removal efficiency in the breathing zone and mass conservation laws. With the developed model, the ventilation parameters corresponding to different fresh outdoor air ratios are quantified to achieve the targeted indoor air quality (i.e., targeted CO2 concentration in the breathing zone). Using the fresh outdoor air ratios and corresponding ventilation parameters as inputs, energy performance evaluations of the air conditioning system are conducted by building energy simulations. The fresh outdoor air ratio with the minimal energy consumption is determined as the optimal one. Experiments show that the mean absolute error of the developed model of CO2 concentration in the breathing zone is 1.9%. The effectiveness of the proposed optimization is demonstrated using TRNSYS that the energy consumption of the air conditioning system with stratum ventilation is reduced by 6.4% while achieving the targeted indoor air quality. The proposed optimization is also promising for other ventilation modes for targeted indoor air quality and improved energy efficiency

    Heat removal efficiency of stratum ventilation for air-side modulation

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    Stratum ventilation has significant thermal non-uniformity between the occupied and upper zones. Although the non-uniformity benefits indoor air quality and energy efficiency, it increases complexities and difficulties in the air-side modulation. In this study, a heat removal efficiency (HRE) model is first established and validated, and then used for the air-side modulation. The HRE model proposed is a function of supply air temperature, supply airflow rate and cooling load. The HRE model proposed has been proven to be applicable to stratum ventilation and displacement ventilation for different room geometries and air terminal configurations, with errors generally within ±5% and a mean absolute error less than 4% for thirty-three experimental cases and five simulated cases. Investigations into the air-side modulation with the proposed HRE model reveal that for both the typical stratum-ventilated classroom and office, the variable-air-volume system can serve a wider range of cooling load than the constant-air-volume system. The assumption of a constant HRE used in the conventional method could lead to errors in the room temperature prediction up to ±1.3 °C, thus the proposed HRE model is important to the air-side modulation for thermal comfort. An air-side modulation method is proposed based on the HRE model to maximize the HRE for improving energy efficiency while maintaining thermal comfort. Results show that the HRE model based air-side modulation can improve the energy efficiency of stratum ventilation up to 67.3%. The HRE model based air-side modulation is also promising for displacement ventilation
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