1. Mining Dynamics of Data Streams in Multi-Dimensional Space
11/9/2018
Mining Dynamics of Data Streams in Multi-Dimensional Space
Jiawei Han
Department of Computer Science
University of Illinois at Urbana-Champaign

2. Challenges of Stream Data Mining
11/9/2018
Challenges of Stream Data Mining
Mining query mode: continuous, ad-hoc, progressive?
Mining mode: batched vs. interactive vs. lazy mining?
Time constraints: real-time?
What patterns to be mined?
Finding patterns, anomaly, differences, …in multiple streams
Mining dynamics (changes, trends and evolutions) of data streams
Multi-level/multi-dimensional processing and data mining
Most stream data are at pretty low-level or multi-dimensional in nature
November 9, 2018
Mining Dynamics of Data Streams

3. Why Mining Dynamics of Data Streams in Multi-Dimensional Space?
11/9/2018
Why Mining Dynamics of Data Streams in Multi-Dimensional Space?
Dynamics (changes, trends and evolutions) of data streams
Perhaps the most interesting thing in streams
Cannot just look at the current data? Save something!
Multi-dimensional stream mining
Most real stream data are at low-level or multi-dimensional in nature
How to examine dynamically at multi-dimensions?
Finding dynamics: patterns and outliers in certain dimensional space
November 9, 2018
Mining Dynamics of Data Streams

4. Stream Data Mining Tasks
Multi-dimensional (on-line) analysis of streams
Clustering data streams
Classification of data streams
Mining frequent patterns in data streams
Mining sequential patterns in data streams
Mining partial periodicity in data streams
Mining notable gradients in data streams
Mining outliers and unusual patterns in data streams
……, more?
November 9, 2018
Mining Dynamics of Data Streams

5. Example 1: Multi-Dimensional (OLAP) Analysis
Analysis of Web click streams
Raw data at low levels: seconds, web page addresses, user IP addresses, …
Analysts want: changes, trends, unusual patterns, at reasonable levels of details
E.g., Average clicking traffic in North America on sports in the last 15 minutes is 40% higher than that in the last 24 hours.”
Analysis of power consumption streams
Raw data: power consumption flow for every household, every minute
Patterns one may find: average hourly power consumption surges up 30% for manufacturing companies in Chicago in the last 2 hours today than that of the same day a week ago
November 9, 2018
Mining Dynamics of Data Streams

6. Example 2: Multi-Dimensional Classification
Dynamic model update for loan or investment
Huge amount of incoming flow of changing information with multiple dimensional space (factors)
E.g., Should we invest this company based on the situation of the current market?
Classification in dynamic (volatile) stock market
Classification of stocks based on their current streams
E.g., Is Lucent going to be up in the next little while?
November 9, 2018
Mining Dynamics of Data Streams

7. Example 3: Hi-Dimensional Clustering
Network intrusion detection
Huge amount of incoming flow of network traffic information, multiple dimensional features in nature
Find burst of activities/traffic in real time
On-line clustering to detect abrupt changes
What are the changes of or text information
Clustering based on frequent terms
Can we perform such clustering in real-time?
November 9, 2018
Mining Dynamics of Data Streams

8. Methodology in Stream Data Mining
Multi-dimensional (on-line) analysis
Mining dynamics of data streams
Time is a special dimension
Tilted time frame (multiple time granularity)
Stream data reduction and pre-computation
What kind of multi-dimensional data to be pre-computed and stored for OLAP analysis?
What kind of data to be pre-computed/stored for classification?
For clustering?
For mining frequent patterns?
For mining sequential patterns? partial periodic patterns? ……
How to do incremental updates? How to find changes?
November 9, 2018
Mining Dynamics of Data Streams

9. ?- Questions in Stream Data Mining
Will stream data mining be real in practice?
Should we develop general stream data mining principles, or ad-doc application-oriented methods?
How are stream data mining methods different from incremental mining?
How are stream data mining linked with stream data management system? With continuous query processing?
Can we do privacy-preserving mining with stream data?
November 9, 2018
Mining Dynamics of Data Streams

10. Mining Dynamics of Data Streams
Thank you !!!
November 9, 2018
Mining Dynamics of Data Streams