UDF stands for:

Pragma facility and SQL3 extension for optimal parallel UDF execution
Role of reduced \udf-cell mass versus impaired \udf-cell function in the pathogenesis of Type 2 Diabetes
Aggregate user defined function (UDF) processing for multi-regression
UDF glucuronyltransferase activity in various rat tissues
Study on gas-solid two-phase flow of steel tube type scraper conveyor based on UDF dynamic mesh
Toward standards for posture. Postural characteristics of the lower back system in normal and pathologic conditions.
Kinematics, Ages, and Metallicities of Star Clusters in NGC 1316 (Fornax A):\ A 3 Gyr Old Merger Remnant
Extragalactic Globular Clusters in the Near-Infrared
Warm IRAS sources. II - Optical spectroscopy of objects from the point source catalog
Extragalactic Globular Clusters in the Near-Infrared