Showing papers by "Patrick Haffner published in 2013"

Understanding the complexity of 3G UMTS network performance

Abstract: With rapid growth in smart phones and mobile data, effectively managing cellular data networks is important in meeting user performance expectations. However, the scale, complexity and dynamics of a large 3G cellular network make it a challenging task to understand the diverse factors that affect its performance. In this paper we study the RNC (Radio Network Controller)-level performance in one of the largest cellular network carriers in US. Using large amount of datasets collected from various sources across the network and over time, we investigate the key factors that influence the network performance in terms of the round-trip times and loss rates (averaged over an hourly time scale). We start by performing the “first-order” property analysis to analyze the correlation and impact of each factor on the network performance. We then apply RuleFit - a powerful supervised machine learning tool that combines linear regression and decision trees - to develop models and analyze the relative importance of various factors in estimating and predicting the network performance. Our analysis culminates with the detection and diagnosis of both “transient” and “persistent” performance anomalies, with discussion on the complex interactions and differing effects of the various factors that may influence the 3G UMTS (Universal Mobile Telecommunications System) network performance.

System and method for training a classifier for natural language understanding

Abstract: Disclosed herein are systems, methods, and computer-readable storage devices for building classifiers in a semi-supervised or unsupervised way. An example system implementing the method can receive a human-generated map which identifies categories of transcriptions. Then the system can receive a set of machine transcriptions. The system can process each machine transcription in the set of machine transcriptions via a set of natural language understanding classifiers, to yield a machine map, the machine map including a set of classifications and a classification score for each machine transcription in the set of machine transcriptions. Then the system can generate silver annotated data by combining the human-generated map and the machine map. The algorithm can include different branches for when the machine transcription is available, when partial results are available, when no results are found for the machine transcription, and so forth.