Semantic Relation Classification via Convolutional Neural Networks with Simple Negative Sampling

Syntactic features play an essential role in identifying relationship in a sentence. Previous neural network models often suffer from irrelevant information introduced when subjects and objects are in a long distance. In this paper, we propose to learn more robust relation representations from the shortest dependency path through a convolution neural network. We further propose a straightforward negative sampling strategy to improve the assignment of subjects and objects. Experimental results show that our method outperforms the state-of-the-art methods on the SemEval-2010 Task 8 dataset

Learning to Predict Charges for Criminal Cases with Legal Basis

The charge prediction task is to determine appropriate charges for a given case, which is helpful for legal assistant systems where the user input is fact description. We argue that relevant law articles play an important role in this task, and therefore propose an attention-based neural network method to jointly model the charge prediction task and the relevant article extraction task in a unified framework. The experimental results show that, besides providing legal basis, the relevant articles can also clearly improve the charge prediction results, and our full model can effectively predict appropriate charges for cases with different expression styles.Comment: 10 pages, accepted by EMNLP 201

Neighborhood Matching Network for Entity Alignment

Structural heterogeneity between knowledge graphs is an outstanding challenge for entity alignment. This paper presents Neighborhood Matching Network (NMN), a novel entity alignment framework for tackling the structural heterogeneity challenge. NMN estimates the similarities between entities to capture both the topological structure and the neighborhood difference. It provides two innovative components for better learning representations for entity alignment. It first uses a novel graph sampling method to distill a discriminative neighborhood for each entity. It then adopts a cross-graph neighborhood matching module to jointly encode the neighborhood difference for a given entity pair. Such strategies allow NMN to effectively construct matching-oriented entity representations while ignoring noisy neighbors that have a negative impact on the alignment task. Extensive experiments performed on three entity alignment datasets show that NMN can well estimate the neighborhood similarity in more tough cases and significantly outperforms 12 previous state-of-the-art methods.Comment: 11 pages, accepted by ACL 202

Generalized Implicit Factorization Problem

The Implicit Factorization Problem was first introduced by May and Ritzenhofen at PKC'09. This problem aims to factorize two RSA moduli $N_1=p_1q_1$ and $N_2=p_2q_2$ when their prime factors share a certain number of least significant bits (LSBs). They proposed a lattice-based algorithm to tackle this problem and extended it to cover $k>2$ RSA moduli. Since then, several variations of the Implicit Factorization Problem have been studied, including the cases where $p_1$ and $p_2$ share some most significant bits (MSBs), middle bits, or both MSBs and LSBs at the same position. In this paper, we explore a more general case of the Implicit Factorization Problem, where the shared bits are located at different and unknown positions for different primes. We propose a lattice-based algorithm and analyze its efficiency under certain conditions. We also present experimental results to support our analysis

Automatic caption generation for news images

This thesis is concerned with the task of automatically generating captions for images, which is important for many image-related applications. Automatic description generation for video frames would help security authorities manage more efficiently and utilize large volumes of monitoring data. Image search engines could potentially benefit from image description in supporting more accurate and targeted queries for end users. Importantly, generating image descriptions would aid blind or partially sighted people who cannot access visual information in the same way as sighted people can. However, previous work has relied on fine-gained resources, manually created for specific domains and applications In this thesis, we explore the feasibility of automatic caption generation for news images in a knowledge-lean way. We depart from previous work, as we learn a model of caption generation from publicly available data that has not been explicitly labelled for our task. The model consists of two components, namely extracting image content and rendering it in natural language. Specifically, we exploit data resources where images and their textual descriptions co-occur naturally. We present a new dataset consisting of news articles, images, and their captions that we required from the BBC News website. Rather than laboriously annotating images with keywords, we simply treat the captions as the labels. We show that it is possible to learn the visual and textual correspondence under such noisy conditions by extending an existing generative annotation model (Lavrenko et al., 2003). We also find that the accompanying news documents substantially complements the extraction of the image content. In order to provide a better modelling and representation of image content,We propose a probabilistic image annotation model that exploits the synergy between visual and textual modalities under the assumption that images and their textual descriptions are generated by a shared set of latent variables (topics). Using Latent Dirichlet Allocation (Blei and Jordan, 2003), we represent visual and textual modalities jointly as a probability distribution over a set of topics. Our model takes these topic distributions into account while finding the most likely keywords for an image and its associated document. The availability of news documents in our dataset allows us to perform the caption generation task in a fashion akin to text summarization; save one important difference that our model is not solely based on text but uses the image in order to select content from the document that should be present in the caption. We propose both extractive and abstractive caption generation models to render the extracted image content in natural language without relying on rich knowledge resources, sentence-templates or grammars. The backbone for both approaches is our topic-based image annotation model. Our extractive models examine how to best select sentences that overlap in content with our image annotation model. We modify an existing abstractive headline generation model to our scenario by incorporating visual information. Our own model operates over image description keywords and document phrases by taking dependency and word order constraints into account. Experimental results show that both approaches can generate human-readable captions for news images. Our phrase-based abstractive model manages to yield as informative captions as those written by the BBC journalists