ESA is an unsupervised approach to word segmentation previously proposed by Wang, which is an iterative process consisting of three phases: Evaluation, Selection and Adjustment. In this article, we propose Ex ESA, the...ESA is an unsupervised approach to word segmentation previously proposed by Wang, which is an iterative process consisting of three phases: Evaluation, Selection and Adjustment. In this article, we propose Ex ESA, the extension of ESA. In Ex ESA, the original approach is extended to a 2-pass process and the ratio of different word lengths is introduced as the third type of information combined with cohesion and separation. A maximum strategy is adopted to determine the best segmentation of a character sequence in the phrase of Selection. Besides, in Adjustment, Ex ESA re-evaluates separation information and individual information to overcome the overestimation frequencies. Additionally, a smoothing algorithm is applied to alleviate sparseness. The experiment results show that Ex ESA can further improve the performance and is time-saving by properly utilizing more information from un-annotated corpora. Moreover, the parameters of Ex ESA can be predicted by a set of empirical formulae or combined with the minimum description length principle.展开更多
Dark matter has been in the discussion of important theories for long time. As technology developed, more and more particles have been suggested to be the candidate of dark matter. This review will first discuss the o...Dark matter has been in the discussion of important theories for long time. As technology developed, more and more particles have been suggested to be the candidate of dark matter. This review will first discuss the observation evidence of the existence of dark matter in the aspect of cosmic microwave background, galaxy rotation curves, velocity dispersions and gravitational lensing. We then focus on some important collider researches, such as HL-LHC and CEPC about dark matter candidates: WIMPs. Finally, we extend the topic considering dark energy and inflation.展开更多
基金supported in part by National Science Foundation of China under Grants No. 61303105 and 61402304the Humanity & Social Science general project of Ministry of Education under Grants No.14YJAZH046+2 种基金the Beijing Natural Science Foundation under Grants No. 4154065the Beijing Educational Committee Science and Technology Development Planned under Grants No.KM201410028017Beijing Key Disciplines of Computer Application Technology
文摘ESA is an unsupervised approach to word segmentation previously proposed by Wang, which is an iterative process consisting of three phases: Evaluation, Selection and Adjustment. In this article, we propose Ex ESA, the extension of ESA. In Ex ESA, the original approach is extended to a 2-pass process and the ratio of different word lengths is introduced as the third type of information combined with cohesion and separation. A maximum strategy is adopted to determine the best segmentation of a character sequence in the phrase of Selection. Besides, in Adjustment, Ex ESA re-evaluates separation information and individual information to overcome the overestimation frequencies. Additionally, a smoothing algorithm is applied to alleviate sparseness. The experiment results show that Ex ESA can further improve the performance and is time-saving by properly utilizing more information from un-annotated corpora. Moreover, the parameters of Ex ESA can be predicted by a set of empirical formulae or combined with the minimum description length principle.
文摘Dark matter has been in the discussion of important theories for long time. As technology developed, more and more particles have been suggested to be the candidate of dark matter. This review will first discuss the observation evidence of the existence of dark matter in the aspect of cosmic microwave background, galaxy rotation curves, velocity dispersions and gravitational lensing. We then focus on some important collider researches, such as HL-LHC and CEPC about dark matter candidates: WIMPs. Finally, we extend the topic considering dark energy and inflation.
