Rain attenuation statistics for an average year in Nonthaburi, Thailand, in 2013-2014, are presented. Particularly, two statistics were calculated from the raw and preprocessed power-level data of the Ku-band beacon s...
详细信息
Rain attenuation statistics for an average year in Nonthaburi, Thailand, in 2013-2014, are presented. Particularly, two statistics were calculated from the raw and preprocessed power-level data of the Ku-band beacon signal received at the Thaicom earth station. These statistics were compared with the ITU-R prediction models in 1999 and 2007-2013. The results show that preprocessing is necessary to generate the statistics and the ITU-R prediction models are not very accurate; the ITU-R models generally tend to underestimate the rain attenuation statistics. Specifically, these models underestimate by more than 4 dB when the availability is more than 99.9%.
Supervised machine learning methods have been widely used in rela- tion extraction that finds the relation between two named entities in a sentence. However, their disadvantages are that constructing training data is ...
详细信息
Supervised machine learning methods have been widely used in rela- tion extraction that finds the relation between two named entities in a sentence. However, their disadvantages are that constructing training data is a cost and time consuming job, and the machine learning system is dependent on the do- main of the training data. To overcome these disadvantages, we construct a weakly labeled data set using distant supervision and propose a relation extrac- tion system using a transformation-based learning (TBL) method. This model showed a high F1-measure (86.57%) for the test data collected using distant su- pervision but a low F1-measure (81.93%) for gold label, due to errors in the training data collected by the distant supervision method.
In spoken information retrieval, users' spoken queries are converted into text queries by using ASR engines. If top-1 results of the ASR engines are incorrect, the errors are propagated to information retrieval sy...
详细信息
In spoken information retrieval, users' spoken queries are converted into text queries by using ASR engines. If top-1 results of the ASR engines are incorrect, the errors are propagated to information retrieval systems. If a docu- ment collection is a small set of short texts, the errors will more affect the per- formances of information retrieval systems. To improve the top-1 accuracies of the ASR engines, we propose a post-processing model to rearrange top-n out- puts of ASR engines by using Ranking SVM. To improve the re-ranking per- formances, the proposed model uses various features such as ASR ranking in- formation, morphological information, and domain-specific lexical information. In the experiments, the proposed model showed the higher precision of 4.4% and the higher recall rate of 6.4% than the baseline model without any post- processing. Based on this experimental result, the proposed model showed that it can be used as a post-processor for improving the performance of a spoken information retrieval system if a document collection is a restricted amount of sentences.
In morpheme-based languages such as Korean and Japanese, spacing and spelling errors that frequently occur in online documents make it difficult to reliably extract informative lexical clues for sentiment analysis. To...
详细信息
Math-aware search engines are required to effectively retrieve mathematical documents including various equations. In this paper, we propose a mathematical document retrieval system by which users can retrieve documen...
详细信息
This work aims to analyze the variation of some parameters in the design of microwave absorbers using FSS. The methodology consists of a combination of two techniques: the equivalent circuit method, which provides the...
详细信息
ISBN:
(纸本)9781467394932
This work aims to analyze the variation of some parameters in the design of microwave absorbers using FSS. The methodology consists of a combination of two techniques: the equivalent circuit method, which provides the transmission and reflection characteristics of the individual structures for a plane wave with normal incidence, and the scattering matrix technique, which provides the result of two FSS cascaded, a conductive FSS and a resistive FSS, getting absorption properties in the projected range. Simulated results are presented and comparison with results obtained with commercial software are made.
Today, human detection and tracking is important challenge for many aims. In this study, we are used Ultra Wide Band (UWB) radar for human respiratory detection behind a wall. The modulated system to get the breathing...
详细信息
暂无评论