Insights from Machine-Learned Diet Success Prediction

To support people trying to lose weight and stay healthy, more and more fitness apps have sprung up including the ability to track both calories intake and expenditure. Users of such apps are part of a wider ``quantified self'' movement and many opt-in to publicly share their logged data. In this paper, we use public food diaries of more than 4,000 long-term active MyFitnessPal users to study the characteristics of a (un-)successful diet. Concretely, we train a machine learning model to predict repeatedly being over or under self-set daily calories goals and then look at which features contribute to the model's prediction. Our findings include both expected results, such as the token ``mcdonalds'' or the category ``dessert'' being indicative for being over the calories goal, but also less obvious ones such as the difference between pork and poultry concerning dieting success, or the use of the ``quick added calories'' functionality being indicative of over-shooting calorie-wise. This study also hints at the feasibility of using such data for more in-depth data mining, e.g., looking at the interaction between consumed foods such as mixing protein- and carbohydrate-rich foods. To the best of our knowledge, this is the first systematic study of public food diaries.Comment: Preprint of an article appearing at the Pacific Symposium on Biocomputing (PSB) 2016 in the Social Media Mining for Public Health Monitoring and Surveillance trac

Similarity measures and diversity rankings for query-focused sentence extraction

Query-focused sentence extraction generally refers to an extractive approach to select a set of sentences that responds to a specific information need. It is one of the major approaches employed in multi-document summarization, focused summarization, and complex question answering. The major advantage of most extractive methods over the natural language processing (NLP) intensive methods is that they are relatively simple, theoretically sound – drawing upon several supervised and unsupervised learning techniques, and often produce equally strong empirical performance. Many research areas, including information retrieval and text mining, have recently moved toward the extractive query-focused sentence generation as its outputs have great potential to support every day‟s information seeking activities. Particularly, as more information have been created and stored online, extractive-based summarization systems may quickly utilize several ubiquitous resources, such as Google search results and social medias, to extract summaries to answer users‟ queries.This thesis explores how the performance of sentence extraction tasks can be improved to create higher quality outputs. Specifically, two major areas are investigated. First, we examine the issue of natural language variation which affects the similarity judgment of sentences. As sentences are much shorter than documents, they generally contain fewer occurring words. Moreover, the similarity notions of sentences are different than those of documents as they tend to be very specific in meanings. Thus many document-level similarity measures are likely to perform well at this level. In this work, we address these issues in two application domains. First, we present a hybrid method, utilizing both unsupervised and supervised techniques, to compute the similarity of interrogative sentences for factoid question reuse. Next, we propose a novel structural similarity measure based on sentence semantics for paraphrase identification and textual entailment recognition tasks. The empirical evaluations suggest the effectiveness of the proposed methods in improving the accuracy of sentence similarity judgments.Furthermore, we examine the effects of the proposed similarity measure in two specific sentence extraction tasks, focused summarization and complex question answering. In conjunction with the proposed similarity measure, we also explore the issues of novelty, redundancy, and diversity in sentence extraction. To that end, we present a novel approach to promote diversity of extracted sets of sentences based on the negative endorsement principle. Negative-signed edges are employed to represent a redundancy relation between sentence nodes in graphs. Then, sentences are reranked according to the long-term negative endorsements from random walk. Additionally, we propose a unified centrality ranking and diversity ranking based on the aforementioned principle. The results from a comprehensive evaluation confirm that the proposed methods perform competitively, compared to many state-of-the-art methods.Ph.D., Information Science -- Drexel University, 201

Using semantic similarity to improve user modeling in web personalization systems

Personalization is a process by which the users are presented with web resources customized to their interests. Critical to the personalization process is the user model which is the system’s representation of the user characteristics and preferences. However, current web personalization systems traditionally use keywords extracted from contents of visited pages as basis of the user models. The keyword extraction technique, based on vector space model, does not consider the semantics of the content which can be used to improve the characterization of the user preferences. Terms which are semantically related, such as car and vehicle, will be treated separately in keyword-based approach. In this study, we propose a method to improve user modeling in web personalization systems by incorporating the semantics of the content. To achieve that, we map keywords extracted from web pages’ content to concepts in domain ontology. The mapping is based on semantic similarity between terms in WordNet taxonomy

Extracting Food Substitutes From Food Diary via Distributional Similarity

In this paper, we explore the problem of identifying substitute relationship between food pairs from real-world food consumption data as the first step towards the healthier food recommendation. Our method is inspired by the distributional hypothesis in linguistics. Specifically, we assume that foods that are consumed in similar contexts are more likely to be similar dietarily. For example, a turkey sandwich can be considered a suitable substitute for a chicken sandwich if both tend to be consumed with french fries and salad. To evaluate our method, we constructed a real-world food consumption dataset from MyFitnessPal's public food diary entries and obtained ground-truth human judgements of food substitutes from a crowdsourcing service. The experiment results suggest the effectiveness of the method in identifying suitable substitutes.Comment: To appear at HealthRecSys'1

Foodbot: A goal-oriented just-in-time healthy eating interventions chatbot

National Research Foundation (NRF) Singapore under International Research Centres in Singapore Funding Initiativ

Does journaling encourage healthier choices? Analyzing healthy eating behaviors of food journalers

Best paper award at DH 2018</p

Influentials, novelty, and social contagion: The viral power of average friends, close communities, and old news

Singapore Management University Office of Research (partial

A tool for teaching principles of image metadata generation

Proceedings of the 6th ACM/IEEE-CS Joint Conference on Digital Libraries, JCDL '06: p. 341.We developed a simple web-based prototype to familiarize students with digital library tools. To assist the students with the indexing task, the prototype provided basic functionalities, including metadata input form, photo search interface. The students generally expressed a positive feedback toward the use of digital library tools in their image indexing project