We propose to study adaptive information retrieval (IR) techniques for two applications in this thesis. The proposed IR techniques include research issues related to data collecting, pre-processing, and processing, graph-based clustering, and input-to-cluster matching.

This thesis focuses on the work of Towards a Query-less News Search Framework as the basic study case to present the usages of the proposed information retrieval techniques. Then we use the work of Diagnosis of the Tropical Moisture Exports to the Mid-Latitudes the Role of Atmospheric Steering in the Extreme Precipitation as another study case to show that the proposed information retrieval techniques can be adaptively applied in other research domain. In both studies, the proposed information retrieval techniques perform...[ Read more ]

We propose to study adaptive information retrieval (IR) techniques for two applications in this thesis. The proposed IR techniques include research issues related to data collecting, pre-processing, and processing, graph-based clustering, and input-to-cluster matching.

This thesis focuses on the work of Towards a Query-less News Search Framework as the basic study case to present the usages of the proposed information retrieval techniques. Then we use the work of Diagnosis of the Tropical Moisture Exports to the Mid-Latitudes the Role of Atmospheric Steering in the Extreme Precipitation as another study case to show that the proposed information retrieval techniques can be adaptively applied in other research domain. In both studies, the proposed information retrieval techniques performed high efficiency and effectively on solving the corresponding research problems.

In Tweets related IR work, we find that given user's interest in a particular news-related tweet, searching for related content may be a tedious process. Formulating an effective search query is not a trivial task and may require query reformulations. And due to the often-small size of smart phone screens, instead of typing, users always prefer click-based operations to retrieve related content.

To address the above issues, we introduce a new paradigm for news-related Twitter search called Search by Tweet(SbT). In this paradigm, a user submits a particular tweet which triggers a search task to retrieve further related tweets. We formalize the SbT problem and propose an effective and efficient framework implementing such a functionality.

At the core, we model the public Twitter stream novelly as a dynamic graph-of-words, reflecting the importance of both words and word correlations. We further develop a streaming clustering algorithm to discover dense word clusters in the graph, corresponding to trending topics. Given an input tweet, our framework utilizes the graph model and word clusters to generate an implicit query.

In Tropical Moisture related IR work, three river basins, i.e., the Yangtze river, the Mississippi river, and the Loire river, were presented as case studies to explore the association among atmospheric circulations, moisture exports and extreme precipitations in the mid-latitudes. The major moisture source regions in the tropics for the three river basins are first identified using the Tropical Moisture Exports (TMEs) dataset

We first retrieve the space-time characteristics of their respective moisture sources. Then, the trajectory curve clustering analysis is applied to the TMEs tracks originating from the identified source regions during each basin's peak TMEs activity and flood seasons. Our results show that the moisture tracks for each basin can be categorized into 3 or 4 clusters with distinct spatial trajectory features. Our further analysis on these clustered trajectories reveals that the contributions of moisture release from different clusters are associated with their trajectory features and travel speeds.

In order to understand the role of associated atmospheric steering, daily composites of the geopotential heights anomalies data and the vertical integral of moisture flux anomalies data from 7 days ahead to the extreme precipitation days (top 5%) are retrieved and examined. The evolutions of the atmospheric circulation patterns and the moisture fluxes are both consistent with the TMEs tracks that contribute more moisture releases to the study regions. The findings imply that atmospheric steering plays an important role in the moisture transport and release, especially for the extreme precipitations.