CRL at Ntcir2

We have developed systems of two types for NTCIR2. One is an enhenced version of the system we developed for NTCIR1 and IREX. It submitted retrieval results for JJ and CC tasks. A variety of parameters were tried with the system. It used such characteristics of newspapers as locational information in the CC tasks. The system got good results for both of the tasks. The other system is a portable system which avoids free parameters as much as possible. The system submitted retrieval results for JJ, JE, EE, EJ, and CC tasks. The system automatically determined the number of top documents and the weight of the original query used in automatic-feedback retrieval. It also determined relevant terms quite robustly. For EJ and JE tasks, it used document expansion to augment the initial queries. It achieved good results, except on the CC tasks.Comment: 11 pages. Computation and Language. This paper describes our results of information retrieval in the NTCIR2 contes

Topic Search for Intelligent Network News Reader HISHO

We have developed an experimental system for retrieving information from network news. It is called the "Intelligent Network News Reader HISHO" and HISHO not only stands for Helpful Information Selection by Hunting On-line but also means "secretary" in Japanese. This system can extract network news articles of interest to a user without requiring the use of keyword-like queries. In contrast to ordinary information-retrieval and abstractgeneration systems, this system uses an "information context " to select articles from news groups on the Internet, and it displays the context visually. This function is called "Topic Search" and helps users grasp the thread of discussions. A salient feature of the HISHO is that it retrieves articles dynamically by adapting itself to the user's interests rather than by classifying them beforehand. Since this system utilizes cross-posted information and conventional expressions, it can refer to information in multiple news groups. We completed a protot..

A Method for Identifying Topic-changing Articles in Discussion-type Newsgroups within the Intelligent Network News Reader HISHO

We are developing an Intelligent Network News Reader for discussion-type newsgroups. It can automatically extract and present articles related to the focus article, which is the article selected by the user. we can automatically retrieve the stream of the discussion as a series of articles by referring to the "References " information that is collected to facilitate the gathering of related articles. To present a suitable number of articles to the user, however, a news reader must be able to gather more related articles when the number of articles is too small and must be able to prune articles which are only weakly related, namely, articles whose central topic is different from previous one when the number of articles is too large. In this paper, therefore, we present a new method for identifying articles which change the topic, a method that uses only clue words and the frequency of strings and does not use dictionaries. An evaluation of our method on real network newsgroups has show..

Japanese probabilistic information retrieval using location and category information

Robertson's 2-poisson information retrieve model does not use location and category information. We constructed a framework using location and category information in a 2-poisson model. We submitted two systems based on this framework to the IREX contest, Japanese language information retrieval contest held in Japan in 1999. For precision in the A-judgement measure they scored 0.4926 and 0.4827, the highest values among the 15 teams and 22 systems that participated in the IREX contest. We describe our systems and the comparative experiments done when various parameters were changed. These experiments confirmed the effectiveness of using location and category information.Comment: 7,8 pages. Computation and Language. IRAL'2000, Hong Kong, September 30, 200

SCENARIO VIOLATION AS GAPS BETWEEN ACTIVITY PATTERNS

In this paper, we propose interactive and visual discovery method of hidden factors for accidents or incidents. Accidents or incidents tend to occur because of very small differences from an ideal situation. From the above viewpoint, we introduce scenario violation model and regard scenario violation as a gap from the proper scenario. Previously, we proposed abduction-based scenario violation determination strategy, but in this paper, we adopt the Kamishibai-KeyGraph to analyze multiple patterns at the same time. Then, we show a gap discovery procedure by using the Kamishibai-KeyGraph.Scenario violation, incident and accident, Kamishibai KeyGraph