Asia
Architecting Dependable Learning-enabled Autonomous Systems: A Survey
Cheng, Chih-Hong, Gulati, Dhiraj, Yan, Rongjie
We provide a summary over architectural approaches that can be used to construct dependable learning-enabled autonomous systems, with a focus on automated driving. We consider three technology pillars for architecting dependable autonomy, namely diverse redundancy, information fusion, and runtime monitoring. For learning-enabled components, we additionally summarize recent architectural approaches to increase the dependability beyond standard convolutional neural networks. We conclude the study with a list of promising research directions addressing the challenges of existing approaches.
EL Embeddings: Geometric construction of models for the Description Logic EL ++
Kulmanov, Maxat, Liu-Wei, Wang, Yan, Yuan, Hoehndorf, Robert
An embedding is a function that maps entities from one algebraic structure into another while preserving certain characteristics. Embeddings are being used successfully for mapping relational data or text into vector spaces where they can be used for machine learning, similarity search, or similar tasks. We address the problem of finding vector space embeddings for theories in the Description Logic $\mathcal{EL}^{++}$ that are also models of the TBox. To find such embeddings, we define an optimization problem that characterizes the model-theoretic semantics of the operators in $\mathcal{EL}^{++}$ within $\Re^n$, thereby solving the problem of finding an interpretation function for an $\mathcal{EL}^{++}$ theory given a particular domain $\Delta$. Our approach is mainly relevant to large $\mathcal{EL}^{++}$ theories and knowledge bases such as the ontologies and knowledge graphs used in the life sciences. We demonstrate that our method can be used for improved prediction of protein--protein interactions when compared to semantic similarity measures or knowledge graph embedding
Learning Factored Markov Decision Processes with Unawareness
Innes, Craig, Lascarides, Alex
Methods for learning and planning in sequential decision problems often assume the learner is aware of all possible states and actions in advance. This assumption is sometimes untenable. In this paper, we give a method to learn factored markov decision problems from both domain exploration and expert assistance, which guarantees convergence to near-optimal behaviour, even when the agent begins unaware of factors critical to success. Our experiments show our agent learns optimal behaviour on small and large problems, and that conserving information on discovering new possibilities results in faster convergence.
Provable Guarantees for Gradient-Based Meta-Learning
Khodak, Mikhail, Balcan, Maria-Florina, Talwalkar, Ameet
We study the problem of meta-learning through the lens of online convex optimization, developing a meta-algorithm bridging the gap between popular gradient-based meta-learning and classical regularization-based multi-task transfer methods. Our method is the first to simultaneously satisfy good sample efficiency guarantees in the convex setting, with generalization bounds that improve with task-similarity, while also being computationally scalable to modern deep learning architectures and the many-task setting. Despite its simplicity, the algorithm matches, up to a constant factor, a lower bound on the performance of any such parameter-transfer method under natural task similarity assumptions. We use experiments in both convex and deep learning settings to verify and demonstrate the applicability of our theory.
Real-time tree search with pessimistic scenarios
Osogami, Takayuki, Takahashi, Toshihiro
Autonomous agents, such as self-driving cars and drones, need to make decisions in real time, which is particularly important but difficult in critical situations for example to avoid collisions. Such decisions often need to be made in a sequential manner to achieve the eventual goal (e.g., avoiding collisions and recovering to safe conditions), under partially observable environment, and by taking into account how other agents behave. Towards this far-reaching goal of realizing such autonomous agents, we propose practical techniques of sequential decision making in real time and demonstrate their effectiveness in Pommerman, a multi-agent environment that has been used in one of the competitions held at the Thirty-second Conference on Neural Information Processing Systems (NeurIPS 2018) on Dec. 8, 2018 Resnick et al. [2018a]. The techniques that we propose in this paper have been used in the Pommerman agents (HakozakiJunctions and dypm-final) who have won the first and third places in the competition. In Pommerman, a team of two agents competes against another team of two agents on a board of 11 11 grids (see Figure 1 (a) for an initial configuration of the board). Each agent can observe only a limited area of the board, and the agents cannot communicate with each other. The goal of a team is to knock down all of the opponents. Towards this goal, the agents place bombs to destroy wooden walls and collect power-up items that might appear from those wooden walls, while avoiding flames and attacking opponents. See Figure 1 (b) for an example of the board in the middle of the game.
Ranking in Genealogy: Search Results Fusion at Ancestry
Jiang, Peng, Yang, Yingrui, Bierner, Gann, Li, Fengjie Alex, Wang, Ruhan, Moghtaderi, Azadeh
Genealogy research is the study of family history using available resources such as historical records. Ancestry provides its customers with one of the world's largest online genealogical index with billions of records from a wide range of sources, including vital records such as birth and death certificates, census records, court and probate records among many others. Search at Ancestry aims to return relevant records from various record types, allowing our subscribers to build their family trees, research their family history, and make meaningful discoveries about their ancestors from diverse perspectives. In a modern search engine designed for genealogical study, the appropriate ranking of search results to provide highly relevant information represents a daunting challenge. In particular, the disparity in historical records makes it inherently difficult to score records in an equitable fashion. Herein, we provide an overview of our solutions to overcome such record disparity problems in the Ancestry search engine. Specifically, we introduce customized coordinate ascent (customized CA) to speed up ranking within a specific record type. We then propose stochastic search (SS) that linearly combines ranked results federated across contents from various record types. Furthermore, we propose a novel information retrieval metric, normalized cumulative entropy (NCE), to measure the diversity of results. We demonstrate the effectiveness of these two algorithms in terms of relevance (by NDCG) and diversity (by NCE) if applicable in the offline experiments using real customer data at Ancestry.
Financial series prediction using Attention LSTM
Financial time series prediction, especially with machine learning techniques, is an extensive field of study. In recent times, deep learning methods (especially time series analysis) have performed outstandingly for various industrial problems, with better prediction than machine learning methods. Moreover, many researchers have used deep learning methods to predict financial time series with various models in recent years. In this paper, we will compare various deep learning models, such as multilayer perceptron (MLP), one-dimensional convolutional neural networks (1D CNN), stacked long short-term memory (stacked LSTM), attention networks, and weighted attention networks for financial time series prediction. In particular, attention LSTM is not only used for prediction, but also for visualizing intermediate outputs to analyze the reason of prediction; therefore, we will show an example for understanding the model prediction intuitively with attention vectors. In addition, we focus on time and factors, which lead to an easy understanding of why certain trends are predicted when accessing a given time series table. We also modify the loss functions of the attention models with weighted categorical cross entropy; our proposed model produces a 0.76 hit ratio, which is superior to those of other methods for predicting the trends of the KOSPI 200.
Distributed Edge Caching via Reinforcement Learning in Fog Radio Access Networks
Lu, Liuyang, Jiang, Yanxiang, Bennis, Mehdi, Ding, Zhiguo, Zheng, Fu-Chun, You, Xiaohu
In this paper, the distributed edge caching problem in fog radio access networks (F-RANs) is investigated. By considering the unknown spatio-temporal content popularity and user preference, a user request model based on hidden Markov process is proposed to characterize the fluctuant spatio-temporal traffic demands in F-RANs. Then, the Q-learning method based on the reinforcement learning (RL) framework is put forth to seek the optimal caching policy in a distributed manner, which enables fog access points (F-APs) to learn and track the potential dynamic process without extra communications cost. Furthermore, we propose a more efficient Q-learning method with value function approximation (Q-VFA-learning) to reduce complexity and accelerate convergence. Simulation results show that the performance of our proposed method is superior to those of the traditional methods.
Momo 'challenge': Police warn over horrifying picture that is adding people on WhatsApp in chilling attack
Police have warned over a chilling "Momo" behaviour on messaging apps that appears to be targeting children. The attack sees malicious people use a horrifying photo – of what appears to be a woman's face attached to a bird's body – which has been given the name Momo. Someone using the horrifying message will add affected children or even adults on messaging apps like WhatsApp, and once they accept use that contact to send a variety of horrifying messages. Police have drawn attention to instances where the contact appeared to encourage children to hold a knife to their throat and threatened their family. The Momo messages are a long-running trend online, having been around at least since summer. But they appear to have flared up once again, leading police in Northern Ireland to watch out for the safety of anyone that might be added by people using the "Momo" image.
Momo 'challenge': What actually is the horrifying trend said to be terrorising children?
The horrifying image known as "Momo", now apparently being used to torment and horrify children on messaging apps such as WhatsApp, has once again been the subject of chilling warnings. Police have this week expressed concern once again about the image, which they say is being used by cyber criminals and other malicious actors to add people on messaging services apparently in an attempt to steal from them. But it is a long-running trend that has spread across the internet in a variety of different forms, with a true story that is almost as strange as the often horrifying false stories that are told about it. Where did Momo really come from? Relatively little is known about where the Momo image, name, or story came from. But it is far from supernatural and mostly explicable.