Overview
Multidimensional Scaling on Multiple Input Distance Matrices
Bai, Song (Huazhong University of Science and Technology) | Bai, Xiang ( Huazhong University of Science and Technology ) | Latecki, Longin Jan ( Temple University ) | Tian, Qi ( University of Texas at San Antonio )
Multidimensional Scaling (MDS) is a classic technique that seeks vectorial representations for data points, given the pairwise distances between them. In recent years, data are usually collected from diverse sources or have multiple heterogeneous representations. However, how to do multidimensional scaling on multiple input distance matrices is still unsolved to our best knowledge. In this paper, we first define this new task formally. Then, we propose a new algorithm called Multi-View Multidimensional Scaling (MVMDS) by considering each input distance matrix as one view. The proposed algorithm can learn the weights of views (i.e., distance matrices) automatically by exploring the consensus information and complementary nature of views. Experimental results on synthetic as well as real datasets demonstrate the effectiveness of MVMDS. We hope that our work encourages a wider consideration in many domains where MDS is needed.
Expectile Matrix Factorization for Skewed Data Analysis
Zhu, Rui (University of Alberta) | Niu, Di (University of Alberta) | Kong, Linglong (University of Alberta ) | Li, Zongpeng (University of Calgary)
Matrix factorization is a popular approach to solving matrix estimation problems based on partial observations. Existing matrix factorization is based on least squares and aims to yield a low-rank matrix to interpret the conditional sample means given the observations. However, in many real applications with skewed and extreme data, least squares cannot explain their central tendency or tail distributions, yielding undesired estimates. In this paper, we propose expectile matrix factorization by introducing asymmetric least squares, a key concept in expectile regression analysis, into the matrix factorization framework. We propose an efficient algorithm to solve the new problem based on alternating minimization and quadratic programming. We prove that our algorithm converges to a global optimum and exactly recovers the true underlying low-rank matrices when noise is zero. For synthetic data with skewed noise and a real-world dataset containing web service response times, the proposed scheme achieves lower recovery errors than the existing matrix factorization method based on least squares in a wide range of settings.
Distant Domain Transfer Learning
Tan, Ben (Hong Kong University of Science and Technology) | Zhang, Yu (Hong Kong University of Science and Technology) | Pan, Sinno Jialin (Nanyang Technological University) | Yang, Qiang (Hong Kong University of Science and Technology)
In this paper, we study a novel transfer learning problem termed Distant Domain Transfer Learning (DDTL). Different from existing transfer learning problems which assume that there is a close relation between the source domain and the target domain, in the DDTL problem, the target domain can be totally different from the source domain. For example, the source domain classifies face images but the target domain distinguishes plane images. Inspired by the cognitive processof human where two seemingly unrelated concepts can be connected by learning intermediate concepts gradually, we propose a Selective Learning Algorithm (SLA) to solve the DDTL problem with supervised autoencoder or supervised convolutional autoencoder as a base model for handling different types of inputs. Intuitively, the SLA algorithm selects usefully unlabeled data gradually from intermediate domains as a bridge to break the large distribution gap for transferring knowledge between two distant domains. Empirical studies on image classification problems demonstrate the effectiveness of the proposed algorithm, and on some tasks the improvement in terms of the classification accuracy is up to 17% over “non-transfer” methods.
Top-k Hierarchical Classification
This paper studies a top-k hierarchical classification problem. In top-k classification, one is allowed to make k predictions and no penalty is incurred if at least one of k predictions is correct. In hierarchical classification, classes form a structured hierarchy, and misclassification costs depend on the relation between the correct class and the incorrect class in the hierarchy. Despite that the fact that both top-k classification and hierarchical classification have gained increasing interests, the two problems have always been studied separately. In this paper, we define a top-k hierarchical loss function using a real world application. We provide the Bayes-optimal solution that minimizes the expected top-k hierarchical misclassification cost. Via numerical experiments, we show that our solution outperforms two baseline methods that address only one of the two issues.
SAT Competition 2016: Recent Developments
Balyo, Tomas ( Karlsruhe Institute of Technology Karlsruhe, Germany ) | Heule, Marijn J. H. (The University of Texas at Austin) | Jarvisalo, Matti (HIIT, Department of Computer Science University of Helsinki, Finland)
We give an overview of SAT Competition 2016, the 2016 edition of thefamous competition for Boolean satisfiability (SAT) solvers with over 20 years of history. A key aim is to point out ``what's hot'' in SAT competitions in 2016, i.e., new developments in thecompetition series, including new competition tracks and new solver techniquesimplemented in some of the award-winning solvers.
What's Hot in Case-Based Reasoning
Goel, Ashok (Georgia Institute of Technology) | Diaz-Agudo, Belen (Complutense University )
Case-based reasoning addresses new problems by remembering and adapting solutions previously used to solve similar problems. Pulled by the increasing number of applications and pushed by a growing interest in memory intensive techniques, research on case-based reasoning appears to be gaining momentum. In this article, we briefly summarize recent developments in research on case-based reasoning based partly on the recent Twenty Fourth International Conference on Case-Based Reasoning.
Strategic Signaling and Free Information Disclosure in Auctions
Alkoby, Shani (Bar-Ilan University) | Sarne, David (Bar-Ilan University) | Milchtaich, Igal (Bar-Ilan University)
With the increasing interest in the role information providers play in multi-agent systems, much effort has been dedicated to analyzing strategic information disclosure and signaling by such agents. This paper analyzes the problem in the context of auctions (specifically for second-price auctions). It provides an equilibrium analysis to the case where the information provider can use signaling according to some pre-committed scheme before introducing its regular (costly) information selling offering. The signal provided, publicly discloses (for free) some of the information held by the information provider. Providing the signaling is thus somehow counter intuitive as the information provider ultimately attempts to maximize her gain from selling the information she holds. Still, we show that such signaling capability can be highly beneficial for the information provider and even improve social welfare. Furthermore, the examples provided demonstrate various possible other beneficial behaviors available to the different players as well as to a market designer, such as paying the information provider to leave the system or commit to a specific signaling scheme. Finally, the paper provides an extension of the underlying model, related to the use of mixed signaling strategies.
Active Video Summarization: Customized Summaries via On-line Interaction with the User
Molino, Ana Garcia del (Institute for Infocomm Research, A*STAR) | Boix, Xavier (Massachusetts Institute of Technology) | Lim, Joo-Hwee (Institute for Infocomm Research, A*STAR) | Tan, Ah-Hwee (Nanyang Technological University)
To facilitate the browsing of long videos, automatic video summarization provides an excerpt that represents its content. In the case of egocentric and consumer videos, due to their personal nature, adapting the summary to specific user's preferences is desirable. Current approaches to customizable video summarization obtain the user's preferences prior to the summarization process. As a result, the user needs to manually modify the summary to further meet the preferences. In this paper, we introduce Active Video Summarization (AVS), an interactive approach to gather the user's preferences while creating the summary. AVS asks questions about the summary to update it on-line until the user is satisfied. To minimize the interaction, the best segment to inquire next is inferred from the previous feedback. We evaluate AVS in the commonly used UTEgo dataset. We also introduce a new dataset for customized video summarization (CSumm) recorded with a Google Glass. The results show that AVS achieves an excellent compromise between usability and quality. In 41% of the videos, AVS is considered the best over all tested baselines, including summaries manually generated. Also, when looking for specific events in the video, AVS provides an average level of satisfaction higher than those of all other baselines after only six questions to the user.
A Summer Research Experience in Robotics
Grimm, Cindy M. (Oregon State University) | Lyman-Holt, Alicia (Oregon State University) | Smart, William D. (Oregon State University)
The Robotics Program at Oregon State University has beenrunning an NSF-funded summer Research Experiences forUndergraduates (REU) site since 2014. Over twenty studentsper year (on average) have participated in the site, spendingten weeks embedded in the OSU Robotics Program. Our mainfocus with this REU Site is to give the participants a com-plete research experience, from problem definition to the fi-nal presentation of results, "in miniature". Our secondary ed-ucational objectives are: 1) Teach basic non-technical skillsneeded for graduate work, such as time management and lit-erature review, 2) Provide details on how to apply to gradu-ate school and for funding, 3) Clarify what we look for in agraduate student, and 4) Detail what to expect from the grad-uate student experience. In this paper, we describe the over-all structure of the participants’ summer experience, outlinesome of the training materials that we use, describe the moti-vations for our approach, and discuss the lessons that we havelearned after running the program for a number of years.
Matrix Factorisation for Scalable Energy Breakdown
Batra, Nipun (IIIT Delhi) | Wang, Hongning (University of Virginia) | Singh, Amarjeet (IIIT Delhi) | Whitehouse, Kamin (University of Virginia)
Homes constitute more than one-thirds of the total energy consumption. Producing an energy breakdown for a home has been shown to reduce household energy consumption by up to 15%, among other benefits. However, existing approaches to produce an energy breakdown require hardware to be installed in each home and are thus prohibitively expensive. In this paper, we propose a novel application of feature-based matrix factorisation that does not require any additional hard- ware installation. The basic premise of our approach is that common design and construction patterns for homes create a repeating structure in their energy data. Thus, a sparse basis can be used to represent energy data from a broad range of homes. We evaluate our approach on 516 homes from a publicly available data set and find it to be more effective than five baseline approaches that either require sensing in each home, or a very rigorous survey across a large number of homes coupled with complex modelling. We also present a deployment of our system as a live web application that can potentially provide energy breakdown to millions of homes.