FP-tree Based Spatial Co-location Pattern Mining

FP-tree Based Spatial Co-location Pattern Mining

Date: May 2005
Creator: Yu, Ping
Description: A co-location pattern is a set of spatial features frequently located together in space. A frequent pattern is a set of items that frequently appears in a transaction database. Since its introduction, the paradigm of frequent pattern mining has undergone a shift from candidate generation-and-test based approaches to projection based approaches. Co-location patterns resemble frequent patterns in many aspects. However, the lack of transaction concept, which is crucial in frequent pattern mining, makes the similar shift of paradigm in co-location pattern mining very difficult. This thesis investigates a projection based co-location pattern mining paradigm. In particular, a FP-tree based co-location mining framework and an algorithm called FP-CM, for FP-tree based co-location miner, are proposed. It is proved that FP-CM is complete, correct, and only requires a small constant number of database scans. The experimental results show that FP-CM outperforms candidate generation-and-test based co-location miner by an order of magnitude.
Contributing Partner: UNT Libraries
Direct Online/Offline Digital Signature Schemes.

Direct Online/Offline Digital Signature Schemes.

Date: December 2008
Creator: Yu, Ping
Description: Online/offline signature schemes are useful in many situations, and two such scenarios are considered in this dissertation: bursty server authentication and embedded device authentication. In this dissertation, new techniques for online/offline signing are introduced, those are applied in a variety of ways for creating online/offline signature schemes, and five different online/offline signature schemes that are proved secure under a variety of models and assumptions are proposed. Two of the proposed five schemes have the best offline or best online performance of any currently known technique, and are particularly well-suited for the scenarios that are considered in this dissertation. To determine if the proposed schemes provide the expected practical improvements, a series of experiments were conducted comparing the proposed schemes with each other and with other state-of-the-art schemes in this area, both on a desktop class computer, and under AVR Studio, a simulation platform for an 8-bit processor that is popular for embedded systems. Under AVR Studio, the proposed SGE scheme using a typical key size for the embedded device authentication scenario, can complete the offline phase in about 24 seconds and then produce a signature (the online phase) in 15 milliseconds, which is the best offline performance of any known ...
Contributing Partner: UNT Libraries
UNT 2005 TREC QA Participation: Using Lemur as IR Search Engine

UNT 2005 TREC QA Participation: Using Lemur as IR Search Engine

Date: 2005
Creator: Chen, Jiangping; Yu, Ping & Ge, He
Description: This paper reports the authors' TREC 2005 QA participation. The authors' QA system Eagle QA developed last year was expanded and modified for this year's QA experiments. Particularly, the authors used Lemur 4.1 as the Information Retrieval (IR) Engine this year to find documents that may contain answers for the test questions from the document collection. The authors' result shows Lemur did a reasonable job on finding relevant documents. But certainly there is room for further improvement.
Contributing Partner: UNT College of Information
Chinese QA and CLQA: NTCIR-5 QA Experiments at UNT

Chinese QA and CLQA: NTCIR-5 QA Experiments at UNT

Date: December 2005
Creator: Chen, Jiangping; Li, Rowena; Yu, Ping; Ge, He; Chin, Pok; Li, Fei et al.
Description: This paper describes our participation in the NTCIR-5 CLQA task.
Contributing Partner: UNT College of Information