Tangible Augmented Reality (AR) enhances user immersion in virtual world by providing haptic feedback through physical proxy objects. However, existing approaches primarily focus on selecting proxy objects based on their global physical properties, neglecting the utilization of local features. Besides, the prevailing strategy of mapping one virtual object to a single dedicated physical proxy creates an inherent switching cost, limiting flexibility and efficiency. Additionally, due to challenges such as real-time performance, generalization and occlusion, the vision-based hand-object tracking remains a difficult task. In this paper, we propose Ubi Grip, an universal hand-object interaction framework for creating grip-based tangible AR applications based on the local graspable feature and a comprehensive hand-object interaction attributes methodology. We employ a lightweight object tracking method to perform tracking, utilizing a hand mask filter and transformation strategy to optimize object pose based on the hand-held properties. Moreover, we design a user-defined workflow for grasping tangible objects, allowing users to switch grips and map interactions. We evaluated our system through comprehensive algorithmic benchmarks and a user study. The benchmarks demonstrate our SOTA performance in object pose estimation and generalization, while the user study validates system usability, providing deeper insights.

Shan Jiang, Christo Wilson. Proceedings of the 59th Annual Meeting of the Association for Computational Linguistics and the 11th International Joint Conference on Natural Language Processing (Volume 1: Long Papers). 2021.

Content moderation, the AI-human hybrid process of removing (toxic) content from social media to promote community health, has attracted increasing attention from lawmakers due to allegations of political bias. Hitherto, this allegation has been made based on anecdotes rather than logical reasoning and empirical evidence, which motivates us to audit its validity. In this paper, we first introduce two formal criteria to measure bias (i.e., independence and separation) and their contextual meanings in content moderation, and then use YouTube as a lens to investigate if the political leaning of a video plays a role in the moderation decision for its associated comments. Our results show that when justifiable target variables (e.g., hate speech and extremeness) are controlled with propensity scoring, the likelihood of comment moderation is equal across left- and right-leaning videos.

Fact-checking, which investigates claims made in public to arrive at a verdict supported by evidence and logical reasoning, has long been a significant form of journalism to combat misinformation in the news ecosystem. Most of the fact-checks share common structured information (called factors) such as claim, claimant, and verdict. In recent years, the emergence of ClaimReview as the standard schema for annotating those factors within fact-checking articles has led to wide adoption of fact-checking features by online platforms (e.g., Google, Bing). However, annotating fact-checks is a tedious process for fact-checkers and distracts them from their core job of investigating claims. As a result, less than half of the fact-checkers worldwide have adopted ClaimReview as of mid-2019. In this paper, we propose the task of factoring fact-checks for automatically extracting structured information from fact-checking articles. Exploring a public dataset of fact-checks, we empirically show that factoring fact-checks is a challenging task, especially for fact-checkers that are under-represented in the existing dataset. We then formulate the task as a sequence tagging problem and fine-tune the pre-trained BERT models with a modification made from our observations to approach the problem. Through extensive experiments, we demonstrate the performance of our models for well-known fact-checkers and promising initial results for under-represented fact-checkers.

The text snippets presented in web search results provide users with a slice of page content that they can quickly scan to help inform their click decisions. However, little is known about how these snippets are generated or how they relate to a user's search query. Motivated by the growing body of evidence suggesting that search engine rankings can influence undecided voters, we conducted an algorithm audit of the political partisanship of Google Search snippets relative to the webpages they are extracted from. To accomplish this, we constructed lexicon of partisan cues to measure partisanship and construct a set of left- and right-leaning search queries. Then, we collected a large dataset of Search Engine Results Pages (SERPs) by running our partisan queries and their autocomplete suggestions on Google Search. After using our lexicon to score the machine-coded partisanship of snippets and webpages, we found that Google Search's snippets generally amplify partisanship, and that this effect is robust across different types of webpages, query topics, and partisan (left- and right-leaning) queries.

Ridesharing services such as Uber and Lyft have become an important part of the Vehicle For Hire (VFH) market, which used to be dominated by taxis. Unfortunately, ridesharing services are not required to share data like taxi services, which has made it challenging to compare the competitive dynamics of these services, or assess their impact on cities. In this paper, we comprehensively compare Uber, Lyft, and taxis with respect to key market features (supply, demand, price, and wait time) in San Francisco and New York City. Based on point pattern statistics, we develop novel statistical techniques to validate our measurement methods. Using spatial lag models, we investigate the accessibility of VFH services, and find that transportation infrastructure and socio-economic features have substantial effects on VFH market features.

Misinformation and fact-checking are opposite forces in the news environment: the former creates inaccuracies to mislead people, while the latter provides evidence to rebut the former. These news articles are often posted on social media and attract user engagement in the form of comments. In this paper, we investigate linguistic (especially emotional and topical) signals expressed in user comments in the presence of misinformation and fact-checking. We collect and analyze a dataset of 5,303 social media posts with 2,614,374 user comments from Facebook, Twitter, and YouTube, and associate these posts to fact-check articles from Snopes and PolitiFact for veracity rulings (i.e., from true to false). We find that linguistic signals in user comments vary significantly with the veracity of posts, e.g., we observe more misinformation-awareness signals and extensive emoji and swear word usage with falser posts. We further show that these signals can help to detect misinformation. In addition, we find that while there are signals indicating positive effects after fact-checking, there are also signals indicating potential "backfire" effects.

There is a growing consensus that online platforms have a systematic influence on the democratic process. However, research beyond social media is limited. In this paper, we report the results of a mixed-methods algorithm audit of partisan audience bias and personalization within Google Search. Following Donald Trump's inauguration, we recruited 187 participants to complete a survey and install a browser extension that enabled us to collect Search Engine Results Pages (SERPs) from their computers. To quantify partisan audience bias, we developed a domain-level score by leveraging the sharing propensities of registered voters on a large Twitter panel. We found little evidence for the "filter bubble'' hypothesis. Instead, we found that results positioned toward the bottom of Google SERPs were more left-leaning than results positioned toward the top, and that the direction and magnitude of overall lean varied by search query, component type (e.g. "answer boxes"), and other factors. Utilizing rank-weighted metrics that we adapted from prior work, we also found that Google's rankings shifted the average lean of SERPs to the right of their unweighted average.

Emerging overlay technologies have enabled to distribute content efficiently over the Internet that in some sense improves the user quality of experience. However, due to inconsistent or even conflicting objectives from the perspectives of multiple co-existing overlay networks and traffic engineering (TE), the interaction among them impacts the performance of each other and results in sub- optimum, which also has not yet been investigated in detail. In this paper, we model this interaction as an n+1-person non-cooperative game, prove the existence of Nash equilibrium point (NEP) and propose an algorithm to compute NEP. In order to overcome the inefficiency of NEP, we define a non-transferable utility (NTU) game based on Shapley NTU game theory, in which overlays and TE share cost efficiently and fairly without side payment, and we propose an algorithm to calculate the Shapley NTU value (SNTUV).

Overlay networks have been widely deployed upon the Internet to provide improved network services. However, the interaction between overlay and traffic engineering (TE) as well as among co-existing overlays may occur. In this paper, we adopt game theoretic approaches to analyze this hybrid interaction. Firstly, we model a situation of the hybrid interaction as an n+1-player non-cooperative game, where overlays and TE are of equal status, and prove the existence of Nash equilibrium (NE). Secondly, we model another situation of the hybrid interaction as a 1-leadern-follower Stackelberg-Nash game, where TE is the leader and coexisting overlays are followers, and prove that the cost at Stackelberg-Nash equilibrium (SNE) is at least as good as that at NE for TE. Thirdly, we propose a cooperative coalition mechanism based on Shapley value to overcome the inherent inefficiency of NE and SNE, where players can improve their performance and form stable coalitions.

Since the emergence of cloud datacenters provides an enormous amount of resources easily accessible to people, it is challenging to provide an efficient search framework in such a distributed environment. However, traditional search techniques only allow users to search images over exact-match keywords through a centralized index. These methods are insufficient to meet requirements of content based image retrieval (CBIR) and more powerful search frameworks are needed. In this paper, we present LCFIR, an effective image retrieval framework for fast content location in the distributed situation. It adopts the peer-to-peer paradigm and combines color and edge features. The basic idea is to construct multiple replicas of an image's index through exploiting the property of Locality Sensitive Hashing (LSH). Thus, the indexes of similar images are probabilistically gathered into the same node without the knowledge of any global information. The empirical results show that the system is able to yield high accuracy with load balancing, and only contacts a few number of the participating nodes.