South America
Quantization Algorithms for Random Fourier Features
The method of random projection (RP) is the standard technique in machine learning and many other areas, for dimensionality reduction, approximate near neighbor search, compressed sensing, etc. Basically, RP provides a simple and effective scheme for approximating pairwise inner products and Euclidean distances in massive data. Closely related to RP, the method of random Fourier features (RFF) has also become popular, for approximating the Gaussian kernel. RFF applies a specific nonlinear transformation on the projected data from random projections. In practice, using the (nonlinear) Gaussian kernel often leads to better performance than the linear kernel (inner product), partly due to the tuning parameter $(\gamma)$ introduced in the Gaussian kernel. Recently, there has been a surge of interest in studying properties of RFF. After random projections, quantization is an important step for efficient data storage, computation, and transmission. Quantization for RP has also been extensive studied in the literature. In this paper, we focus on developing quantization algorithms for RFF. The task is in a sense challenging due to the tuning parameter $\gamma$ in the Gaussian kernel. For example, the quantizer and the quantized data might be tied to each specific tuning parameter $\gamma$. Our contribution begins with an interesting discovery, that the marginal distribution of RFF is actually free of the Gaussian kernel parameter $\gamma$. This small finding significantly simplifies the design of the Lloyd-Max (LM) quantization scheme for RFF in that there would be only one LM quantizer for RFF (regardless of $\gamma$). We also develop a variant named LM$^2$-RFF quantizer, which in certain cases is more accurate. Experiments confirm that the proposed quantization schemes perform well.
MaskCycleGAN-VC: Learning Non-parallel Voice Conversion with Filling in Frames
Kaneko, Takuhiro, Kameoka, Hirokazu, Tanaka, Kou, Hojo, Nobukatsu
Non-parallel voice conversion (VC) is a technique for training voice converters without a parallel corpus. Cycle-consistent adversarial network-based VCs (CycleGAN-VC and CycleGAN-VC2) are widely accepted as benchmark methods. However, owing to their insufficient ability to grasp time-frequency structures, their application is limited to mel-cepstrum conversion and not mel-spectrogram conversion despite recent advances in mel-spectrogram vocoders. To overcome this, CycleGAN-VC3, an improved variant of CycleGAN-VC2 that incorporates an additional module called time-frequency adaptive normalization (TFAN), has been proposed. However, an increase in the number of learned parameters is imposed. As an alternative, we propose MaskCycleGAN-VC, which is another extension of CycleGAN-VC2 and is trained using a novel auxiliary task called filling in frames (FIF). With FIF, we apply a temporal mask to the input mel-spectrogram and encourage the converter to fill in missing frames based on surrounding frames. This task allows the converter to learn time-frequency structures in a self-supervised manner and eliminates the need for an additional module such as TFAN. A subjective evaluation of the naturalness and speaker similarity showed that MaskCycleGAN-VC outperformed both CycleGAN-VC2 and CycleGAN-VC3 with a model size similar to that of CycleGAN-VC2. Audio samples are available at http://www.kecl.ntt.co.jp/people/kaneko.takuhiro/projects/maskcyclegan-vc/index.html.
Benchmarking and Survey of Explanation Methods for Black Box Models
Bodria, Francesco, Giannotti, Fosca, Guidotti, Riccardo, Naretto, Francesca, Pedreschi, Dino, Rinzivillo, Salvatore
The widespread adoption of black-box models in Artificial Intelligence has enhanced the need for explanation methods to reveal how these obscure models reach specific decisions. Retrieving explanations is fundamental to unveil possible biases and to resolve practical or ethical issues. Nowadays, the literature is full of methods with different explanations. We provide a categorization of explanation methods based on the type of explanation returned. We present the most recent and widely used explainers, and we show a visual comparison among explanations and a quantitative benchmarking.
QNLP in Practice: Running Compositional Models of Meaning on a Quantum Computer
Lorenz, Robin, Pearson, Anna, Meichanetzidis, Konstantinos, Kartsaklis, Dimitri, Coecke, Bob
Quantum Natural Language Processing (QNLP) deals with the design and implementation of NLP models intended to be run on quantum hardware. In this paper, we present results on the first NLP experiments conducted on Noisy Intermediate-Scale Quantum (NISQ) computers for datasets of size >= 100 sentences. Exploiting the formal similarity of the compositional model of meaning by Coecke et al. (2010) with quantum theory, we create representations for sentences that have a natural mapping to quantum circuits. We use these representations to implement and successfully train two NLP models that solve simple sentence classification tasks on quantum hardware. We describe in detail the main principles, the process and challenges of these experiments, in a way accessible to NLP researchers, thus paving the way for practical Quantum Natural Language Processing.
Spanish Biomedical and Clinical Language Embeddings
Gutiérrez-Fandiño, Asier, Armengol-Estapé, Jordi, Carrino, Casimiro Pio, De Gibert, Ona, Gonzalez-Agirre, Aitor, Villegas, Marta
We have developed two types of embeddings using We evaluated the Biomedical Word Embeddings two different corpora: the Spanish Biomedical Corpora obtaining better results than previous versions showing and the Spanish Clinical Corpora. Since the the implication that with more data, we obtain Spanish Biomedical Corpora is of a much larger magnitude better representations.
ZJUKLAB at SemEval-2021 Task 4: Negative Augmentation with Language Model for Reading Comprehension of Abstract Meaning
Xie, Xin, Chen, Xiangnan, Chen, Xiang, Wang, Yong, Zhang, Ningyu, Deng, Shumin, Chen, Huajun
This paper presents our systems for the three Subtasks of SemEval Task4: Reading Comprehension of Abstract Meaning (ReCAM). We explain the algorithms used to learn our models and the process of tuning the algorithms and selecting the best model. Inspired by the similarity of the ReCAM task and the language pre-training, we propose a simple yet effective technology, namely, negative augmentation with language model. Evaluation results demonstrate the effectiveness of our proposed approach. Our models achieve the 4th rank on both official test sets of Subtask 1 and Subtask 2 with an accuracy of 87.9% and an accuracy of 92.8%, respectively. We further conduct comprehensive model analysis and observe interesting error cases, which may promote future researches.
LazyFormer: Self Attention with Lazy Update
Ying, Chengxuan, Ke, Guolin, He, Di, Liu, Tie-Yan
Improving the efficiency of Transformer-based language pre-training is an important task in NLP, especially for the self-attention module, which is computationally expensive. In this paper, we propose a simple but effective solution, called \emph{LazyFormer}, which computes the self-attention distribution infrequently. LazyFormer composes of multiple lazy blocks, each of which contains multiple Transformer layers. In each lazy block, the self-attention distribution is only computed once in the first layer and then is reused in all upper layers. In this way, the cost of computation could be largely saved. We also provide several training tricks for LazyFormer. Extensive experiments demonstrate the effectiveness of the proposed method.
Biden Faces a Steep Challenge to Unite Democracies on Tech
In a February 19 speech at the Munich Security Conference, delivered virtually from the White House, President Joe Biden declared, "We must shape the rules that will govern the advance of technologies and the norms of behavior in cyberspace, artificial intelligence, biotechnology, so they are used to lift people up, not used to pin them down." A few weeks earlier, during an address at the State Department's Truman Building, the president said, "Diplomacy is back at the center of our foreign policy." The Trump administration's undermining of years of work on internet diplomacy makes technology an ever more vital (and challenging) element of renewed US engagement abroad. Digital issues are no longer extricable from "traditional" foreign policy issues across trade, human rights, and security. And as the new White House starts to navigate these waters, one idea in particular has become a sort of bumper sticker for an overarching strategy: Unite democracies on technology. As the Chinese and Russian governments become more technologically assertive and undermine human rights, and as democracies grapple with how to appropriately implement rules and regulations for the likes of artificial intelligence systems, this work is essential.
US Navy tests orbiting solar panel that could one day beam power anywhere on Earth
A pizza box sized solar panel in orbit is producing enough electricity to power an iPad, according to a succesful test of the technology by the US Navy. The Photovoltaic Radiofrequency Antenna Module (PRAM) was launched in May 2020 attached to a drone that loops around the Earth every 90 minutes and is designed to harness light from the sun to convert to electricity. The 12x12 inch panel is an early experiment for a technology that could one day harness solar radiation from the sun and beam it to anywhere on the Earth. It is designed to make the best use of light in space, which doesn't have to pass through the atmosphere where it loses energy before reaching the ground. The Pentagon one day envisages an array of panels in space that could send power to even the most remote parts of the planet and create a new global power grid.
How Google's hot air balloon surprised its creators
They had spent many months honing an algorithm designed to steer an unmanned hot air balloon all the way from Puerto Rico to Peru. The balloon, controlled by its machine mind, kept veering off course. Salvatore Candido of Google's now-defunct Project Loon venture, which aimed to bring internet access to remote areas via the balloons, couldn't explain the craft's trajectory. His colleagues manually took control of the system and put it back on track. It was only later that they realised what was happening.