272 research outputs found
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The Dynamics of China's Bio-Fuel Industry and Its Policy Options
The economic development of China following the changes in 1978-79 has transformed the country from a poor nation to being the second largest economy in the world. The change came about as China focused on manufacturing industry as a driver of economic growth. This has led to an increasing demand for energy and thus to a greater reliance on fossil fuels. Concerns for greenhouse gas (GHG) emissions and global warming have also created a huge pressure from the world for China to reduce emissions that accompany extensive use of fossil fuels. The sustainability of the growth and the economic stability of the country faces a severe threat as available reserves of crude oil and coal in China and in the world are limited, making it highly unlikely that the country can continue to depend on these resources for its future energy needs. Because China imports more than half of its oil requirement, it needs to find viable alternatives to decrease its trust on continuing import. Biofuels appear as one such alternative and China has invested in setting up manufacturing facilities for producing bio-ethanol from cereals and cassava. However, the existing production has helped substitute only about 8% of oil requirement and 0.45% of its overall energy needs. On the other hand, diversion of grain, sugarcane, soybeans etc for biofuel production creates shortage in the supply of food leading into high prices and need to import food, sugar, and oil that will affect its trade balance negatively. This report investigates the different aspects of the crises of energy and food security that China faces, which will only become more severe in the very near future. The aim of the analysis is to make some recommendations that can help reduce the negative effects of these issues. Analysis shows that China needs to diversify its risks and take major initiatives to increase production of biofuels for this will simultaneously reduce its dependence on oil and reduce GHG emissions. In order to do so, China needs to shift focus from a manufacturing intensive economy toward horizontal and vertical growth of the agriculture sector. While this happens, it will have to use its vast positive balance of payments to import food
Carbon-Efficient Neural Architecture Search
This work presents a novel approach to neural architecture search (NAS) that
aims to reduce energy costs and increase carbon efficiency during the model
design process. The proposed framework, called carbon-efficient NAS (CE-NAS),
consists of NAS evaluation algorithms with different energy requirements, a
multi-objective optimizer, and a heuristic GPU allocation strategy. CE-NAS
dynamically balances energy-efficient sampling and energy-consuming evaluation
tasks based on current carbon emissions. Using a recent NAS benchmark dataset
and two carbon traces, our trace-driven simulations demonstrate that CE-NAS
achieves better carbon and search efficiency than the three baselines
Neural Architecture Search using Deep Neural Networks and Monte Carlo Tree Search
Neural Architecture Search (NAS) has shown great success in automating the
design of neural networks, but the prohibitive amount of computations behind
current NAS methods requires further investigations in improving the sample
efficiency and the network evaluation cost to get better results in a shorter
time. In this paper, we present a novel scalable Monte Carlo Tree Search (MCTS)
based NAS agent, named AlphaX, to tackle these two aspects. AlphaX improves the
search efficiency by adaptively balancing the exploration and exploitation at
the state level, and by a Meta-Deep Neural Network (DNN) to predict network
accuracies for biasing the search toward a promising region. To amortize the
network evaluation cost, AlphaX accelerates MCTS rollouts with a distributed
design and reduces the number of epochs in evaluating a network by transfer
learning, which is guided with the tree structure in MCTS. In 12 GPU days and
1000 samples, AlphaX found an architecture that reaches 97.84\% top-1 accuracy
on CIFAR-10, and 75.5\% top-1 accuracy on ImageNet, exceeding SOTA NAS methods
in both the accuracy and sampling efficiency. Particularly, we also evaluate
AlphaX on NASBench-101, a large scale NAS dataset; AlphaX is 3x and 2.8x more
sample efficient than Random Search and Regularized Evolution in finding the
global optimum. Finally, we show the searched architecture improves a variety
of vision applications from Neural Style Transfer, to Image Captioning and
Object Detection.Comment: To appear in the Thirty-Fourth AAAI conference on Artificial
Intelligence (AAAI-2020
Data-driven Piecewise Affine Decision Rules for Stochastic Programming with Covariate Information
Focusing on stochastic programming (SP) with covariate information, this
paper proposes an empirical risk minimization (ERM) method embedded within a
nonconvex piecewise affine decision rule (PADR), which aims to learn the direct
mapping from features to optimal decisions. We establish the nonasymptotic
consistency result of our PADR-based ERM model for unconstrained problems and
asymptotic consistency result for constrained ones. To solve the nonconvex and
nondifferentiable ERM problem, we develop an enhanced stochastic
majorization-minimization algorithm and establish the asymptotic convergence to
(composite strong) directional stationarity along with complexity analysis. We
show that the proposed PADR-based ERM method applies to a broad class of
nonconvex SP problems with theoretical consistency guarantees and computational
tractability. Our numerical study demonstrates the superior performance of
PADR-based ERM methods compared to state-of-the-art approaches under various
settings, with significantly lower costs, less computation time, and robustness
to feature dimensions and nonlinearity of the underlying dependency
Online Leadership for Open Source Project Success: Evidence from the GitHub Blockchain Projects
Blockchain technology has become increasingly popular in recent years. However, only 8% of blockchain open source projects are maintained actively on GitHub. Drawing on the online leadership literature, this study seeks to understand the correlation between leader characteristics and success of blockchain open source projects from the behavioral (knowledge contribution), structural (social capital) and cognitive (openness orientation) dimensions. Considering the unique decentralization nature of blockchain, this study further investigates the contingency effect of blockchain archetypes with empirical evidence from GitHub. Our findings provide novel insights for understanding the determinants of blockchain open source project success and leadership behaviors in the online community
Pre-training Multi-party Dialogue Models with Latent Discourse Inference
Multi-party dialogues are more difficult for models to understand than
one-to-one two-party dialogues, since they involve multiple interlocutors,
resulting in interweaving reply-to relations and information flows. To step
over these obstacles, an effective way is to pre-train a model that understands
the discourse structure of multi-party dialogues, namely, to whom each
utterance is replying. However, due to the lack of explicitly annotated
discourse labels in multi-party dialogue corpora, previous works fail to scale
up the pre-training process by putting aside the unlabeled multi-party
conversational data for nothing. To fully utilize the unlabeled data, we
propose to treat the discourse structures as latent variables, then jointly
infer them and pre-train the discourse-aware model by unsupervised latent
variable inference methods. Experiments on multiple downstream tasks show that
our pre-trained model outperforms strong baselines by large margins and
achieves state-of-the-art (SOTA) results, justifying the effectiveness of our
method. The official implementation of this paper is available at
https://github.com/EricLee8/MPD_EMVI.Comment: Accepted by ACL 202
A Deep Learning Based Model for Driving Risk Assessment
In this paper a novel multilayer model is proposed for assessing driving risk. Studying aggressive behavior via massive driving data is essential for protecting road traffic safety and reducing losses of human life and property in smart city context. In particular, identifying aggressive behavior and driving risk are multi-factors combined evaluation process, which must be processed with time and environment. For instance, improper time and environment may facilitate abnormal driving behavior. The proposed Dynamic Multilayer Model consists of identifying instant aggressive driving behavior that can be visited within specific time windows and calculating individual driving risk via Deep Neural Networks based classification algorithms. Validation results show that the proposed methods are particularly effective for identifying driving aggressiveness and risk level via real dataset of 2129 drivers’ driving behavior
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