Localizing News by Vladimir Ermakov

Mapping News Vladimir Ermakov, RI Abstract Naïve Bayes and Fisher Method Classifiers Experiment Results: Test Error 18 The amount of informa:on available in electronic •  Work with classes given by Placemaker 16 format is rapidly increasing. It is possible to find out •  Mul:class One-‐vs.-‐One classifica:on. 14 real-‐:me about the current events in a par:cular part •  Naïve Bayes uses feature probabili:es to 12 Random of the world based on electronic data such as news construct whole document probability. 10 Naïve Bayes Fisher ar:cles, blog entries, twièr feeds and SMS messages. Axis Title •  Fisher Method calculates the probability of a 8 SVM Not only is the data available, there is an overwhelming category for each feature and compares against 6 Lemma:zed SVM Op:mal amount of it and it is hard to stay on top of events that random chance of category. are of relevance. Gebng informed about recent 4 •  Fisher Method provides easier selec:on of developments is par:cularly important in the :mes of decision boundaries. 2 crisis, when lives could depend on :mely response. In 0 this project I am exploring ways to pinpoint the loca:on discussed in text documents. I am able to SoluCon: SVM on First PosiCon and Count Mapping News: Reuters 2010 achieve good results by combining loca:on keywords Chinas push for new talks with North Korea is extracted by Yahoo! Placemaker service with state of no subsCtute for acCon aJer Pyongyangs deadly aLack on a South Korean island… the art machine learning and natural language processing techniques. Chinas push for new talks with North Korea is no subsCtute for acCon aJer Pyongyangs deadly Overview of Document ClassificaCon aLack on a South Korean island… • Feature Extrac:on: Bag of Words,String Kernels CN – First Index: 0, Count: 1 • Higher Level Features: Topic Modeling KP – First Index: 32, Count: 2 KR – First Index:121, Count: 1 • Linguis:c pre-‐processing: lemma:za:on, stemming • Natural Language Processing • Named En:ty Recogni:on SVM KP: NORTH KOREA United States:36297 Great Britain:6841 • Mul:-‐class classifica:on: One-‐vs.-‐One, One-‐vs.-‐All Russia:545 Hai::203 Experiment Setup Watching for Important Events • Reuters-‐21578 Dataset: News Ar:cles with Hand-‐labeled Jan 12 – Hai: Earthquake Loca:ons. • Yahoo Placemaker: Extract Loca:ons • Convert loca:ons to Country Codes: Over 160 Codes. • Run Classifica:on Mar 29 – Moscow Subway Bombing • Check Against Human Labels • Best Achievable Error Rate – 4.5%* • Random Error Rate – 17.1%

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Localizing News by Vladimir Ermakov

by Ushahidi on Jan 23, 2011

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Localizing News by Vladimir Ermakov — Presentation Transcript