Browsing by Author Zhang, Xin

Jump to: 0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
or enter first few letters:  
Showing results [1 - 2] / 2
  • Authors: Zhang, Xin (2006)

    Events occur in every aspect of our lives. An unexpectedly large number of events occurring within some certain measurement (e.g. within some time du-ration or a spatial region) is called a burst, suggesting unusual behaviors or activities. Bursts come up in many natural and social processes. It is a challenging task to monitor the occurrence of bursts whose lasting duration is unknown in a fast data stream environment. This work describes efficient data structures and algorithms for high performance burst detection under different settings. Our view is that bursts, as unusual phenomena, constitute a useful preliminary primitive in a knowledge discovery hierarchy. Our intent is to bu...
  • Authors: Zhang, Xin (2006)

    Advances in chromatography have led to two recent active areas of study: the reduction of particle size for column packing and development of monolithic materials. Reducing the size of the packing material leads to an increase in chromatographic efficiency and a decrease in the analysis time. The monolithic column is composed of one single piece of material with through-pores that offers very high permeability, thereby, allowing the column can offer a variable external porosity and operation at high linear velocity with low pressure requirements. The performance of commercially available columns, a monolith and a sub-2 gm particle packed column was examined. Higher efficiencies were o...