1,547 research outputs found
Harvesting Green Energy from Blue Ocean in Taiwan: Patent Mapping and Regulation Analyzing
Taiwan is an island with abundant oceanic resources but devoid of resources to significantly utilize ocean power. In fact, the Taiwanese government has initiated several renewable energy policies to transform its energy supply structure from brown (fossil fuel-based) sources of energy to green (renewable-based) energy. In addition, in the 4th National Energy Conference held in 2015, ocean energy was identified as a key contributor to renewable energy source. Therefore, the Taiwanese government proposed the construction of a MW-scale demonstration electricity plant, powered by ocean energy, as promptly as possible. Compared with solar PV, wind, and biomass (waste) energy, the development of ocean energy in Taiwan has lagged behind. Therefore, the aim of this chapter is to boost ocean energy adaptation using analysis from technical and legal perspectives. This chapter first illustrates the ocean energy potential and develop blueprint in Taiwan. Next, through patent research from the Taiwan Patent Search System, this chapter identifies advantageous ocean power technologies innovated by Taiwanese companies, primarily wave and current technologies. Furthermore, through the examination of regulations and competent authorities, this chapter discusses the possible challenges for implementing ocean energy technologies in Taiwan
Efficient Neural Network Robustness Certification with General Activation Functions
Finding minimum distortion of adversarial examples and thus certifying
robustness in neural network classifiers for given data points is known to be a
challenging problem. Nevertheless, recently it has been shown to be possible to
give a non-trivial certified lower bound of minimum adversarial distortion, and
some recent progress has been made towards this direction by exploiting the
piece-wise linear nature of ReLU activations. However, a generic robustness
certification for general activation functions still remains largely
unexplored. To address this issue, in this paper we introduce CROWN, a general
framework to certify robustness of neural networks with general activation
functions for given input data points. The novelty in our algorithm consists of
bounding a given activation function with linear and quadratic functions, hence
allowing it to tackle general activation functions including but not limited to
four popular choices: ReLU, tanh, sigmoid and arctan. In addition, we
facilitate the search for a tighter certified lower bound by adaptively
selecting appropriate surrogates for each neuron activation. Experimental
results show that CROWN on ReLU networks can notably improve the certified
lower bounds compared to the current state-of-the-art algorithm Fast-Lin, while
having comparable computational efficiency. Furthermore, CROWN also
demonstrates its effectiveness and flexibility on networks with general
activation functions, including tanh, sigmoid and arctan.Comment: Accepted by NIPS 2018. Huan Zhang and Tsui-Wei Weng contributed
equall
Building a 3.5 m prototype interferometer for the Q & A vacuum birefringence experiment and high precision ellipsometry
We have built and tested a 3.5 m high-finesse Fabry-Perot prototype
inteferometer with a precision ellipsometer for the QED test and axion search
(Q & A) experiment. We use X-pendulum-double-pendulum suspension designs and
automatic control schemes developed by the gravitational-wave detection
community. Verdet constant and Cotton-Mouton constant of the air are measured
as a test. Double modulation with polarization modulation 100 Hz and
magnetic-field modulation 0.05 Hz gives 10^{-7} rad phase noise for a 44-minute
integration.Comment: This draft has been presented in the 5th Edoardo Amaldi Conference on
Gravitational Wave
Towards Fast Computation of Certified Robustness for ReLU Networks
Verifying the robustness property of a general Rectified Linear Unit (ReLU)
network is an NP-complete problem [Katz, Barrett, Dill, Julian and Kochenderfer
CAV17]. Although finding the exact minimum adversarial distortion is hard,
giving a certified lower bound of the minimum distortion is possible. Current
available methods of computing such a bound are either time-consuming or
delivering low quality bounds that are too loose to be useful. In this paper,
we exploit the special structure of ReLU networks and provide two
computationally efficient algorithms Fast-Lin and Fast-Lip that are able to
certify non-trivial lower bounds of minimum distortions, by bounding the ReLU
units with appropriate linear functions Fast-Lin, or by bounding the local
Lipschitz constant Fast-Lip. Experiments show that (1) our proposed methods
deliver bounds close to (the gap is 2-3X) exact minimum distortion found by
Reluplex in small MNIST networks while our algorithms are more than 10,000
times faster; (2) our methods deliver similar quality of bounds (the gap is
within 35% and usually around 10%; sometimes our bounds are even better) for
larger networks compared to the methods based on solving linear programming
problems but our algorithms are 33-14,000 times faster; (3) our method is
capable of solving large MNIST and CIFAR networks up to 7 layers with more than
10,000 neurons within tens of seconds on a single CPU core.
In addition, we show that, in fact, there is no polynomial time algorithm
that can approximately find the minimum adversarial distortion of a
ReLU network with a approximation ratio unless
=, where is the number of neurons in the network.Comment: Tsui-Wei Weng and Huan Zhang contributed equall
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