Improving Term Frequency Normalization for Multi-topical Documents, and Application to Language Modeling Approaches

Term frequency normalization is a serious issue since lengths of documents are various. Generally, documents become long due to two different reasons - verbosity and multi-topicality. First, verbosity means that the same topic is repeatedly mentioned by terms related to the topic, so that term frequency is more increased than the well-summarized one. Second, multi-topicality indicates that a document has a broad discussion of multi-topics, rather than single topic. Although these document characteristics should be differently handled, all previous methods of term frequency normalization have ignored these differences and have used a simplified length-driven approach which decreases the term frequency by only the length of a document, causing an unreasonable penalization. To attack this problem, we propose a novel TF normalization method which is a type of partially-axiomatic approach. We first formulate two formal constraints that the retrieval model should satisfy for documents having verbose and multi-topicality characteristic, respectively. Then, we modify language modeling approaches to better satisfy these two constraints, and derive novel smoothing methods. Experimental results show that the proposed method increases significantly the precision for keyword queries, and substantially improves MAP (Mean Average Precision) for verbose queries.Comment: 8 pages, conference paper, published in ECIR '0

Skill performance in Cardiopulmonary Resuscitation among Laypersons and health care professionals

Cardiopulmonary resuscitation (CPR) is the key determinant for survival from out-of-hospital cardiac arrest. The skill and ability of the rescuer to perform quality CPR are important to assure the success or failure of survival. This study aims to explore the differences and factors that affect performance of CPR skills, by taking into account demographic variations between the Health Care Professionals (HCP) and laypersons. A total of 144 responders were interviewed using a self-administered questionnaire and a skill evaluation checklist by two qualified instructors. HCP and laypersons groups report comparable skill retention in CPR but HCP shows better basic life support (BLS) knowledge. Results suggest female HCP has better BLS knowledge compared to male HCP and time length after first BLS course contributes to significant difference in BLS knowledge among laypersons. Laypersons who had attended refresher course have better CPR skill rentention compared to those who had not

Three-dimensional Magnetic Restructuring in Two Homologous Solar Flares in the Seismically Active NOAA AR 11283

We carry out a comprehensive investigation comparing the three-dimensional magnetic field restructuring, flare energy release, and the helioseismic response, of two homologous flares, the 2011 September 6 X2.1 (FL1) and September 7 X1.8 (FL2) flares in NOAA AR 11283. In our analysis, (1) a twisted flux rope (FR) collapses onto the surface at a speed of 1.5 km/s after a partial eruption in FL1. The FR then gradually grows to reach a higher altitude and collapses again at 3 km/s after a fuller eruption in FL2. Also, FL2 shows a larger decrease of the flux-weighted centroid separation of opposite magnetic polarities and a greater change of the horizontal field on the surface. These imply a more violent coronal implosion with corresponding more intense surface signatures in FL2. (2) The FR is inclined northward, and together with the ambient fields, it undergoes a southward turning after both events. This agrees with the asymmetric decay of the penumbra observed in the peripheral regions. (3) The amounts of free magnetic energy and nonthermal electron energy released during FL1 are comparable to those of FL2 within the uncertainties of the measurements. (4) No sunquake was detected in FL1; in contrast, FL2 produced two seismic emission sources S1 and S2 both lying in the penumbral regions. Interestingly, S1 and S2 are connected by magnetic loops, and the stronger source S2 has weaker vertical magnetic field. We discuss these results in relation to the implosion process in the low corona and the sunquake generation.Comment: 12 pages, 9 figures, accepted to the Astrophysical Journa

Use staged reading to improve sentences reading skill in Chinese language teaching: qualitative research management

This study was to examine the effectiveness in improving the skills of reading sentences. Skills in reading sentences focus on teaching and learning Chinese. In the study, the samples were identified as non-Chinese students. They are among those who use or learn Chinese as a second language. The method used in this study is reading stages. The methodology of this study is qualitative. The study was conducted in one of Sekolah Jenis Kebangsaan Cina (SJKC) or Chinese National Type School in Lawas, Sarawak, Malaysia. The samples selected were 4 students who are studying in year one based on their results in the summative evaluation on the Chinese Language subject at this point. The research data will be collected and analyzed through observation, interviews, record reflections of researcher and also the supporting documents. Through the data obtained from the 3 cycles of studies, students can recognize available samples and pronounce of 5 simple words, 5 average difficult words and 5 difficult words with correct pronunciation. Samples students can also read at least two simple sentences, 1 average difficult sentence and 1 difficult sentence correctly, fluently and with the correct intonation