Goto

Collaborating Authors

 ddcrp


Reviews: Beyond Exchangeability: The Chinese Voting Process

Neural Information Processing Systems

The exchangeability under a probabilistic model gives a great flexibility in building and inferencing, while preventing the representation power of a model. Although the problem is interesting, the presentation of this paper makes hard to understand the proposed approach. Especially, the structure and notations hinder readers from understanding some key ideas. Below I listed some suggestions and comments to improve the paper: * a short description of the reinforcing mechanism between the CRP and ddCRP: ddCRP is an important concept of the proposed approach, which breaks the general exchangeability assumption. But It is quite hard to get an intuition about how this model works to compare with the CRP.


Spatial distance dependent Chinese restaurant processes for image segmentation

Neural Information Processing Systems

The distance dependent Chinese restaurant process (ddCRP) was recently introduced to accommodate random partitions of non-exchangeable data [1]. The dd-CRP clusters data in a biased way: each data point is more likely to be clustered with other data that are near it in an external sense. This paper examines the dd-CRP in a spatial setting with the goal of natural image segmentation. We explore the biases of the spatial ddCRP model and propose a novel hierarchical extension better suited for producing "human-like" segmentations. We then study the sensitivity of the models to various distance and appearance hyperparameters, and provide the first rigorous comparison of nonparametric Bayesian models in the image segmentation domain. On unsupervised image segmentation, we demonstrate that similar performance to existing nonparametric Bayesian models is possible with substantially simpler models and algorithms.


Spatial distance dependent Chinese restaurant processes for image segmentation

Neural Information Processing Systems

The distance dependent Chinese restaurant process (ddCRP) was recently introduced to accommodate random partitions of non-exchangeable data. The ddCRP clusters data in a biased way: each data point is more likely to be clustered with other data that are near it in an external sense. This paper examines the ddCRP in a spatial setting with the goal of natural image segmentation. We explore the biases of the spatial ddCRP model and propose a novel hierarchical extension better suited for producing "human-like" segmentations. We then study the sensitivity of the models to various distance and appearance hyperparameters, and provide the first rigorous comparison of nonparametric Bayesian models in the image segmentation domain.


Spatial distance dependent Chinese restaurant processes for image segmentation

Ghosh, Soumya, Ungureanu, Andrei B., Sudderth, Erik B., Blei, David M.

Neural Information Processing Systems

The distance dependent Chinese restaurant process (ddCRP) was recently introduced to accommodate random partitions of non-exchangeable data. The ddCRP clusters data in a biased way: each data point is more likely to be clustered with other data that are near it in an external sense. This paper examines the ddCRP in a spatial setting with the goal of natural image segmentation. We explore the biases of the spatial ddCRP model and propose a novel hierarchical extension better suited for producing "human-like" segmentations. We then study the sensitivity of the models to various distance and appearance hyperparameters, and provide the first rigorous comparison of nonparametric Bayesian models in the image segmentation domain.


A Nonparametric Bayesian Model for Sparse Temporal Multigraphs

Ghalebi, Elahe, Mahyar, Hamidreza, Grosu, Radu, Taylor, Graham W., Williamson, Sinead A.

arXiv.org Machine Learning

As the availability and importance of temporal interaction data--such as email communication--increases, it becomes increasingly important to understand the underlying structure that underpins these interactions. Often these interactions form a multigraph, where we might have multiple interactions between two entities. Such multigraphs tend to be sparse yet structured, and their distribution often evolves over time. Existing statistical models with interpretable parameters can capture some, but not all, of these properties. We propose a dynamic nonparametric model for interaction multigraphs that combines the sparsity of edge-exchangeable multigraphs with dynamic clustering patterns that tend to reinforce recent behavioral patterns. We show that our method yields improved held-out likelihood over stationary variants, and impressive predictive performance against a range of state-of-the-art dynamic graph models.


Interaction Point Processes via Infinite Branching Model

Lin, Peng (NICTA and the University of New South Wales) | Zhang, Bang (NICTA ) | Guo, Ting (NICTA) | Wang, Yang (NICTA) | Chen, Fang (NICTA)

AAAI Conferences

Many natural and social phenomena can be modeled by interaction point processes (IPPs) (Diggle et al. 1994), stochastic point processes considering the interaction between points. In this paper, we propose the infinite branching model (IBM), a Bayesian statistical model that can generalize and extend some popular IPPs, e.g., Hawkes process (Hawkes 1971; Hawkes and Oakes 1974). It treats IPP as a mixture of basis point processes with the aid of a distance dependent prior over branching structure that describes the relationship between points. The IBM can estimate point event intensity, interaction mechanism and branching structure simultaneously. A generic Metropolis-within-Gibbs sampling method is also developed for model parameter inference. The experiments on synthetic and real-world data demonstrate the superiority of the IBM.


A Hierarchical Distance-dependent Bayesian Model for Event Coreference Resolution

Yang, Bishan, Cardie, Claire, Frazier, Peter

arXiv.org Machine Learning

We present a novel hierarchical distance-dependent Bayesian model for event coreference resolution. While existing generative models for event coreference resolution are completely unsupervised, our model allows for the incorporation of pairwise distances between event mentions -- information that is widely used in supervised coreference models to guide the generative clustering processing for better event clustering both within and across documents. We model the distances between event mentions using a feature-rich learnable distance function and encode them as Bayesian priors for nonparametric clustering. Experiments on the ECB+ corpus show that our model outperforms state-of-the-art methods for both within- and cross-document event coreference resolution.


Sketch the Storyline with CHARCOAL: A Non-Parametric Approach

Tang, Siliang (Zhejiang University) | Wu, Fei (Zhejiang University) | Li, Si (Zhejiang University) | Lu, Weiming (Zhejiang University) | Zhang, Zhongfei (Zhejiang University) | Zhuang, Yueting (Zhejiang University)

AAAI Conferences

Generating a coherent synopsis and revealing the development threads for news stories from the increasing amounts of news content remains aformidable challenge. In this paper, we proposed a hddCRP (hybird distant-dependent ChineseRestaurant Process) based HierARChical tOpic model for news Article cLustering, abbreviated as CHARCOAL. Given a bunch of news articles, the outcome of CHARCOAL is threefold: 1) it aggregates relevant new articles into clusters (i.e., stories); 2) it disentangles the chain links (i.e., storyline) between articles in their describing story; 3) it discerns the topics that each story is assigned (e.g., Malaysia Airlines Flight 370 story belongs to the aircraft accident topic and U.S presidential election stories belong to the politics topic). CHARCOAL completes this task by utilizing a hddCRP as prior, and the entities (e.g., names of persons, organizations, or locations) that appear in news articles as clues. Moveover, the adaptation of nonparametric nature in CHARCOAL makes our model can adaptively learn the appropriate number of stories and topics from news corpus. The experimental analysis and results demonstrate both interpretability and superiority of the proposed approach.


From Deformations to Parts: Motion-based Segmentation of 3D Objects

Ghosh, Soumya, Loper, Matthew, Sudderth, Erik B., Black, Michael J.

Neural Information Processing Systems

We develop a method for discovering the parts of an articulated object from aligned meshes of the object in various three-dimensional poses. We adapt the distance dependentChinese restaurant process (ddCRP) to allow nonparametric discovery ofa potentially unbounded number of parts, while simultaneously guaranteeing a spatially connected segmentation. To allow analysis of datasets in which object instances have varying 3D shapes, we model part variability across poses via affine transformations. By placing a matrix normal-inverse-Wishart prior on these affine transformations, we develop a ddCRP Gibbs sampler which tractably marginalizes over transformation uncertainty. Analyzing a dataset of humans captured indozens of poses, we infer parts which provide quantitatively better deformation predictionsthan conventional clustering methods.


Spatial distance dependent Chinese restaurant processes for image segmentation

Ghosh, Soumya, Ungureanu, Andrei B., Sudderth, Erik B., Blei, David M.

Neural Information Processing Systems

The distance dependent Chinese restaurant process (ddCRP) was recently introduced toaccommodate random partitions of non-exchangeable data [1]. The dd-CRP clusters data in a biased way: each data point is more likely to be clustered with other data that are near it in an external sense. This paper examines the dd-CRP in a spatial setting with the goal of natural image segmentation. We explore the biases of the spatial ddCRP model and propose a novel hierarchical extension bettersuited for producing "humanlike" segmentations. We then study the sensitivity of the models to various distance and appearance hyperparameters, and provide the first rigorous comparison of nonparametric Bayesian models in the image segmentationdomain. On unsupervised image segmentation, we demonstrate that similar performance to existing nonparametric Bayesian models is possible with substantially simpler models and algorithms.