Asia
Real-time Power System State Estimation and Forecasting via Deep Neural Networks
Zhang, Liang, Wang, Gang, Giannakis, Georgios B.
Contemporary smart power grids are being challenged by rapid voltage fluctuations, due to large-scale deployment of renewable generation, electric vehicles, and demand response programs. In this context, monitoring the grid's operating conditions in real time becomes increasingly critical. With the emergent large scale and nonconvexity however, past optimization based power system state estimation (PSSE) schemes are computationally expensive or yield suboptimal performance. To bypass these hurdles, this paper advocates deep neural networks (DNNs) for real-time power system monitoring. By unrolling a state-of-the-art prox-linear SE solver, a novel modelspecific DNN is developed for real-time PSSE, which entails a minimal tuning effort, and is easy to train. To further enable system awareness even ahead of the time horizon, as well as to endow the DNN-based estimator with resilience, deep recurrent neural networks (RNNs) are pursued for power system state forecasting. Deep RNNs exploit the long-term nonlinear dependencies present in the historical voltage time series to enable forecasting, and they are easy to implement. Numerical tests showcase improved performance of the proposed DNN-based estimation and forecasting approaches compared with existing alternatives. Empirically, the novel model-specific DNN-based PSSE offers nearly an order of magnitude improvement in performance over competing alternatives, including the widely adopted Gauss-Newton PSSE solver, in our tests using real load data on the IEEE 118-bus benchmark system.
Concept Learning through Deep Reinforcement Learning with Memory-Augmented Neural Networks
Shi, Jing, Xu, Jiaming, Yao, Yiqun, Xu, Bo
Deep neural networks have shown superior performance in many regimes to remember familiar patterns with large amounts of data. However, the standard supervised deep learning paradigm is still limited when facing the need to learn new concepts efficiently from scarce data. In this paper, we present a memory-augmented neural network which is motivated by the process of human concept learning. The training procedure, imitating the concept formation course of human, learns how to distinguish samples from different classes and aggregate samples of the same kind. In order to better utilize the advantages originated from the human behavior, we propose a sequential process, during which the network should decide how to remember each sample at every step. In this sequential process, a stable and interactive memory serves as an important module. We validate our model in some typical one-shot learning tasks and also an exploratory outlier detection problem. In all the experiments, our model gets highly competitive to reach or outperform those strong baselines.
CGMH: Constrained Sentence Generation by Metropolis-Hastings Sampling
Miao, Ning, Zhou, Hao, Mou, Lili, Yan, Rui, Li, Lei
In real-world applications of natural language generation, there are often constraints on the target sentences in addition to fluency and naturalness requirements. Existing language generation techniques are usually based on recurrent neural networks (RNNs). However, it is non-trivial to impose constraints on RNNs while maintaining generation quality, since RNNs generate sentences sequentially (or with beam search) from the first word to the last. In this paper, we propose CGMH, a novel approach using Metropolis-Hastings sampling for constrained sentence generation. CGMH allows complicated constraints such as the occurrence of multiple keywords in the target sentences, which cannot be handled in traditional RNN-based approaches. Moreover, CGMH works in the inference stage, and does not require parallel corpora for training. We evaluate our method on a variety of tasks, including keywords-to-sentence generation, unsupervised sentence paraphrasing, and unsupervised sentence error correction. CGMH achieves high performance compared with previous supervised methods for sentence generation. Our code is released at https://github.com/NingMiao/CGMH
A Grammar-Based Structural CNN Decoder for Code Generation
Sun, Zeyu, Zhu, Qihao, Mou, Lili, Xiong, Yingfei, Li, Ge, Zhang, Lu
Code generation maps a program description to executable source code in a programming language. Existing approaches mainly rely on a recurrent neural network (RNN) as the decoder. However, we find that a program contains significantly more tokens than a natural language sentence, and thus it may be inappropriate for RNN to capture such a long sequence. In this paper, we propose a grammar-based structural convolutional neural network (CNN) for code generation. Our model generates a program by predicting the grammar rules of the programming language; we design several CNN modules, including the tree-based convolution and pre-order convolution, whose information is further aggregated by dedicated attentive pooling layers. Experimental results on the HearthStone benchmark dataset show that our CNN code generator significantly outperforms the previous state-of-the-art method by 5 percentage points; additional experiments on several semantic parsing tasks demonstrate the robustness of our model. We also conduct in-depth ablation test to better understand each component of our model.
Session-based Recommendation with Graph Neural Networks
Wu, Shu, Tang, Yuyuan, Zhu, Yanqiao, Wang, Liang, Xie, Xing, Tan, Tieniu
The problem of session-based recommendation aims to predict user actions based on anonymous sessions. Previous methods model a session as a sequence and estimate user representations besides item representations to make recommendations. Though achieved promising results, they are insufficient to obtain accurate user vectors in sessions and neglect complex transitions of items. To obtain accurate item embedding and take complex transitions of items into account, we propose a novel method, i.e. Session-based Recommendation with Graph Neural Networks, SR-GNN for brevity. In the proposed method, session sequences are modeled as graph-structured data. Based on the session graph, GNN can capture complex transitions of items, which are difficult to be revealed by previous conventional sequential methods. Each session is then represented as the composition of the global preference and the current interest of that session using an attention network. Extensive experiments conducted on two real datasets show that SR-GNN evidently outperforms the state-of-the-art session-based recommendation methods consistently.
Exploiting Sentence Embedding for Medical Question Answering
Hao, Yu, Liu, Xien, Wu, Ji, Lv, Ping
Despite the great success of word embedding, sentence embedding remains a not-well-solved problem. In this paper, we present a supervised learning framework to exploit sentence embedding for the medical question answering task. The learning framework consists of two main parts: 1) a sentence embedding producing module, and 2) a scoring module. The former is developed with contextual self-attention and multi-scale techniques to encode a sentence into an embedding tensor. This module is shortly called Contextual self-Attention Multi-scale Sentence Embedding (CAMSE). The latter employs two scoring strategies: Semantic Matching Scoring (SMS) and Semantic Association Scoring (SAS). SMS measures similarity while SAS captures association between sentence pairs: a medical question concatenated with a candidate choice, and a piece of corresponding supportive evidence. The proposed framework is examined by two Medical Question Answering(MedicalQA) datasets which are collected from real-world applications: medical exam and clinical diagnosis based on electronic medical records (EMR). The comparison results show that our proposed framework achieved significant improvements compared to competitive baseline approaches. Additionally, a series of controlled experiments are also conducted to illustrate that the multi-scale strategy and the contextual self-attention layer play important roles for producing effective sentence embedding, and the two kinds of scoring strategies are highly complementary to each other for question answering problems.
An Introduction to Fuzzy & Annotated Semantic Web Languages
We present the state of the art in representing and reasoning with fuzzy knowledge in Semantic Web Languages such as triple languages RDF/RDFS, conceptual languages of the OWL 2 family and rule languages. We further show how one may generalise them to so-called annotation domains, that cover also e.g.
Over 80% of Japanese positive about robotic nursing care
Over 80 percent of people in Japan are positive about receiving nursing care from robots, according to a survey by Orix Living Corp., a nursing care service provider. The result suggested that people feel a psychological burden from being taken care of by humans, Orix Living said. The online survey, conducted in September, covered 1,238 people in their 40s or older across the country. The proportion of respondents who said they are ready to or want to receive nursing care from robots stood at 84.3 percent, hitting the highest level since a related question was introduced in 2011. Of the respondents who prefer not to use robotic nursing care, 46.9 percent, the largest group, said they want to be taken care of by humans.
Internet 'hijack' sees Google traffic misdirected through China and Russia in possible war-game experiment
Large parts of the internet went down for more than an hour on Monday after a strange incident meant web traffic intended to reach Google was rerouted through China and Russia. The web giant said its search engine, as well as apps like Spotify that rely on its services, stopped working as a result. Google did not reveal how many users were affected, though researchers from the network-intelligence company ThousandEyes reported instances of web traffic being redirected from the UK, France and the US. The researchers said the misdirected traffic was of particular concern given the list of countries through which large amounts of sensitive data was passing. The incident "put valuable Google traffic in the hands of ISPs in countries with a long history of internet surveillance," ThousandEyes researcher Ameet Naik wrote in a blog post.
Alibaba Pulls In Record Singles Day Sales
A natural showman, Mr. Ma is usually an outsize presence at the gala--but not this year. In September, he said he plans to retire next year as executive chairman and hand the reins to Chief Executive Daniel Zhang. Mr. Ma was present at the event, but didn't take his usual star turn on stage. Instead, he appeared in a prerecorded video that showed him competing against Alibaba employees at tasks including delivering meals, taping packages and tieing up crabs. An Alibaba representative said the founder's participation in the annual gala is "different every year."