365,655 research outputs found
New Liu Estimators for the Poisson Regression Model: Method and Application
Full text linkA new shrinkage estimator for the Poisson model is introduced in this paper. This method is a generalization of the Liu (1993) estimator originally developed for the linear regression model and will be generalised here to be used instead of the classical maximum likelihood (ML) method in the presence of multicollinearity since the mean squared error (MSE) of ML becomes inflated in that situation. Furthermore, this paper derives the optimal value of the shrinkage parameter and based on this value some methods of how the shrinkage parameter should be estimated are suggested. Using Monte Carlo simulation where the MSE and mean absolute error (MAE) are calculated it is shown that when the Liu estimator is applied with these proposed estimators of the shrinkage parameter it always outperforms the ML. Finally, an empirical application has been considered to illustrate the usefulness of the new Liu estimators.Estimation; MSE; MAE; Multicollinearity; Poisson; Liu; Simulation
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Ruidocollaris obscura Liu 1999
No full text<i>Ruidocollaris obscura</i> (Liu, 1999) <p>(Figs. 7, 16, 27, 37, 54, 63, 73, 81, 92)</p> <p> <i>Rudicollaris obscura</i> Liu, 1999: 131. (sphalm.) <i>Ruidocollaris obscura</i> Liu, 1999. <b>syn. nov.</b></p> <p> <b>Examined material.</b> 1 male (holotype), 1 male (paratype), 2 females (paratype), China: Guangxi Prov.: Xinan, Maoershan Nature Reserve, 450–650m, Coll. Liu Xianwei, Yin Haisheng (MSIE); 1 male, China: Guangxi Prov.: Zhongfeng, Coll. Huang jinsun, 1980. VIII.21 (IZAS, No. 360945); 1 male, China: Guangxi Prov.: Guilin, Maoershan Mt. nature reserve, Gaoping Spot, Coll. Liu Chunxiang, 2007. VII.3 (IZAS); 5 males, 4 females, China: Guangxi Prov.: Longsheng, Huaping Nature Reserve, Cujiang Spot, 700m, 2007. VII.15–X.5, Coll. Liu Chunxiang (IZAS).</p> <p> <b>Additional description.</b> Male stridulatory teeth gradually becoming smaller from middle to both ends, including about 80 distinct stridulatory teeth and 20 indistinct apical stridulatory teeth (Fig. 27).</p> <p>Measurements (mm). Length of body: male 27.0, female 27.0; of pronotum: male 7.0, female 7.0; height of paranota: male 5.8; length of paranota: male 4.6; of tegmen: male 39.0, female 40.0; largest width of tegmen: male 9.9, female 11.2; length of hind wing: male 42.3, female 42.3; of posterior femur: male 23.0, female 24.0; of apical style of male: 1.12; length of ovipositor 7.0; largest width of ovipositor 3.4.</p> <p> <b>Discussion.</b> Liu (1999) erroneously spelt the genus <i>Ruidocollaris</i> as “ <i>Rudicollaris</i> ”. At the same time, the generic name of all mentioned species in the genus were spelt by mistake, and this species was also erroneously spelt as “ <i>Rudicollaris obscura</i> Liu, <b>sp. nov.</b> ”, when published. Here we just correct the generic name of the species.</p> <p> <b>Distribution</b> (Fig. 98). China (Fujian Prov., Guangdong Prov., Guangxi Prov., Sichuan Prov.).</p>Published as part of <i>Liu, Chun-Xiang & Kang, Le, 2010, A review of the genus Ruidocollaris Liu (Orthoptera: Tettigoniidae), with description of six new species from China, pp. 36-60 in Zootaxa 2664</i> on page 54, DOI: <a href="http://zenodo.org/record/276329">10.5281/zenodo.276329</a>
Wang Jieru, Liu Fang, Wang Qiugui
No full textSide A. 王節如, 刘枋 (Both sides) -- Side B. 刘枋, 王節如, 王秋桂.Live recording."7/13/79"--Spine.Electronic reproduction from Rulan Chao Pian Audio Cassette Collection.Spoken in Chinese.Side A. Wang Jieru, Liu Fang (Both sides) -- Side B. Liu Fang, Wang Jieru, Wang Qiugui
WT LP01 from Liu lab, Yale
No full textType four secretion system, T4SS<strong>Tilt Series Date:</strong> 2016-11-28</p>
<strong>Data Taken By:</strong> Yuxi Liu</p>
<strong>Species / Specimen:</strong> Legionella pneumophila</p>
<strong>Strain:</strong> Philadelphia-1_Lp02</p>
<strong>Tilt Series Settings:</strong> Single Axis, tilt range: (-51.0°, 51.0°), step: 3°, constant angular increment, dosage: 50.0 eV/Ų, defocus: -5.0 μm, magnification: 15500x. </p>
<strong>Microscope:</strong> Caltech Polara</p>
<strong>Acquisition Software:</strong> Serial EM</p>
<strong>Upload Method:</strong> pipeline</p>
<strong>Processing Software Used:</strong> None</p>
<strong>Collaborators and Roles:</strong> Data collected by Bo Hu in Jun Liu lab at Yale from their Polara. Partial WT strain data set. Primary literature: doi: 10.1038/s41564-018-0165-z</p>Files available via S3 at https://renc.osn.xsede.org/ini210004tommorrell/tomography_archive/ylx2016-11-28-101</p>LP02Jan30A030_driftcorr.mrc, Tilt Series (Pixel Size 0.25 nm), 280.0 B
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Neochauliodes parasparsus Liu & Yang
No full text<i>Neochauliodes parasparsus</i> Liu & Yang <p>(Fig. 43)</p> <p> <i>Neochauliodes parasparsus</i> Liu & Yang, 2005a. Entomol. Sci. 8: 298. Type locality: Henan (Neixiang, Xishan, Songxian, Luanchuan), Shannxi (Xunyangba, Zhenba, Zhen–an, Foping, Xunyang, Ningshan, Zhouzhi), Shanxi (Yuanqu), Hubei (Zigui, Xingshan, Shennongjia), Gansu (Kangxian).</p> <p> <b>Distribution.</b> China (Gansu, Henan, Hubei, Shannxi, Shanxi).</p> <p> <b> <i>Neochauliodes parcus</i> Liu & Yang</b> </p> <p>(Fig. 45)</p> <p> <i>Neochauliodes parcus</i> Liu & Yang, 2006a. Ann. Zool. 56: 192. Type locality: Yunnan (Sanchahe, Mangshi).</p> <p> <b>Distribution.</b> China (Yunnan).</p>Published as part of <i>Liu, Xingyue, Hayashi, Fumio & Yang, Ding, 2007, Revision of the Neochauliodes sinensis species-group (Megaloptera: Corydalidae: Chauliodinae), pp. 29-54 in Zootaxa 1511 (1)</i> on pages 42-43, DOI: 10.11646/zootaxa.1511.1.3, <a href="http://zenodo.org/record/5087291">http://zenodo.org/record/5087291</a>
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