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抗诉与协征之间:近代天津商人团体与所得税稽征 被引量:7
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作者 魏文享 《中国经济史研究》 CSSCI 北大核心 2017年第4期72-87,共16页
所得税在晚清民初尝试开征,至1936年成功推行。天津商会及各业公会作为工商界之团体代表,在所得税立法及征稽过程中成为抗议行动先锋。20世纪20年代,天津商会汇集本地意见,与上海、北京等地团体互为声援,表达抗议。至国民政府时期,天津... 所得税在晚清民初尝试开征,至1936年成功推行。天津商会及各业公会作为工商界之团体代表,在所得税立法及征稽过程中成为抗议行动先锋。20世纪20年代,天津商会汇集本地意见,与上海、北京等地团体互为声援,表达抗议。至国民政府时期,天津商人团体协同立场,以天津情形特殊,苛捐未除,表达暂缓诉求。未已,天津沦陷于日本铁蹄之下,市政大权为治安维持会掌控。敌伪政府并未放弃这一重要税源,对税法稍加修正即恢复。经历整顿改组的商人团体无力抗衡伪政府,但为维持经营,仍成立各业停征所得税后援会,支持商会与伪政府展开交涉。抗战光复后,国民党政府因内战财政支绌,合并征收所利得税。至1948年,甚至加重以六倍预征。天津商会一直表达反对意见,但在政府压力下仍要协助税务部门进行税额统计、核查、宣传事宜。跨越不同时期的政经格局,商人团体始终借助舆论及呈请表达税权,力求减税,履行着纳税人团体的角色。官方迫于财政需要始终保持高压态势,商人团体又不得不参与协征。然在抗诉与协征之间,商会作为纳税人团体的集体代理权及行动力受到政治空间和时局的影响,难以对官方征税形成有效制衡。 展开更多
关键词 协征 抗诉 天津 所得税 商人团体
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商会协征与机构扣缴:近代广东所得税的征稽
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作者 魏文享 苏腾飞 《江西社会科学》 CSSCI 北大核心 2020年第9期115-126,255,256,共14页
所得税在1936年开征之后,依税法规定,本应由所得税机构按申报查征制度直接征收。但在战时秩序下,为尽快征得税款,税局在效率优先的目标下,不断寻找更为实用的稽征路径。直接税署颁布的简化稽征程序,为税局采用委托代理方法征税打开政策... 所得税在1936年开征之后,依税法规定,本应由所得税机构按申报查征制度直接征收。但在战时秩序下,为尽快征得税款,税局在效率优先的目标下,不断寻找更为实用的稽征路径。直接税署颁布的简化稽征程序,为税局采用委托代理方法征税打开政策空间。在广东省之征收中,商会协征与机构扣缴,一直是税局保持征收效率的关键。这与所得税立法之时坚持直征模式已渐行渐远,然在当时却被视为常理常规,为政府和商民所接受。这在短期看来可以提升效率,但也为税务人员的权力寻租和商民逃税留下制度缝隙,长期观之有损所得税的公平与普遍原则。 展开更多
关键词 商会协征 机构扣缴 广东 所得税 内战
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矢量介子协变手征有效场理论研究 被引量:1
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作者 王彦 杨继锋 《华东师范大学学报(自然科学版)》 CAS CSCD 北大核心 2020年第1期67-75,共9页
在协变形式的手征有效场论中,分析探索了涉及自旋为1的矢量场的圈图计算中保持手征幂次规则的减除方案.着重研究了的含矢量介子内线的Goldstone标量玻色子自能一圈图计算,在矢量场的两种表示下进行了计算分析并得到了一致的结果.计算表... 在协变形式的手征有效场论中,分析探索了涉及自旋为1的矢量场的圈图计算中保持手征幂次规则的减除方案.着重研究了的含矢量介子内线的Goldstone标量玻色子自能一圈图计算,在矢量场的两种表示下进行了计算分析并得到了一致的结果.计算表明,文献中建议的EOMS[1](Extended On-Mass Shell)可以消除破坏手征幂次规则的贡献;细致分析后发现,破坏手征幂次规则的项都是定域的.由此提出了更简洁的扩展的MS(Extended MS,EMS)方案,并进一步用顶角图计算做了检验.与EOMS相比,该方案仅仅消除破坏手征幂次规则的定域项,对非定域的手征贡献不需做任何修改.这意味着该方案下手征微扰计算的收敛性会更好,更适合作为研究重强子手征有效场理论的方案. 展开更多
关键词 变手微扰理论 矢量介子 幂次规则 EOMS 扩展的MS
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核子-核子散射协变手征有效场论的两圈图研究
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作者 孙进 杨继锋 《华东师范大学学报(自然科学版)》 CAS CSCD 北大核心 2020年第2期90-97,共8页
从协变手征有效理论出发,计算了核子-核子(Nucleon-Nucleon,N-N)散射两圈图振幅.两圈图是以箱图为骨架并对π介子自能进行修正所得.在减除时,采用两种减除方案:MS和EMS(Extended MS).由MS得到的振幅严重破坏手征微扰展开的幂次规则,由EM... 从协变手征有效理论出发,计算了核子-核子(Nucleon-Nucleon,N-N)散射两圈图振幅.两圈图是以箱图为骨架并对π介子自能进行修正所得.在减除时,采用两种减除方案:MS和EMS(Extended MS).由MS得到的振幅严重破坏手征微扰展开的幂次规则,由EMS得到的振幅中仅余非定域"反常"贡献,剩下的均是满足手征幂次规则的贡献. 展开更多
关键词 变手有效场论 MS方案 EMS方案 幂次规则
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SU(3)协变手征有效理论与八重态重子质量修正
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作者 刘舟 杨继锋 《华东师范大学学报(自然科学版)》 CAS CSCD 北大核心 2022年第4期103-113,共11页
在SU(3)协变手征有效理论框架下,计算了基于奇异夸克贡献的八重态、十重态重子对八重态重子质量的一圈图修正;发现破坏手征幂律规则的都是定域项,可通过定域抵消项减除,从而指向一个更为简洁的减除方案——扩展的极小减除(Extended Mini... 在SU(3)协变手征有效理论框架下,计算了基于奇异夸克贡献的八重态、十重态重子对八重态重子质量的一圈图修正;发现破坏手征幂律规则的都是定域项,可通过定域抵消项减除,从而指向一个更为简洁的减除方案——扩展的极小减除(Extended Minimal Subtraction,EMS)方案;除了手征贡献,计算还保留了相对论修正项.这对精确计算重子质量的修正有价值,并对解析外推有重要贡献. 展开更多
关键词 变手有效场论 八重态重子 幂律规则 EMS方案
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Synergistic effect of fatty liver and smoking on metabolic syndrome 被引量:12
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作者 Po-Hsin Chiang Tsui-Yen Chang Jong-Dar Chen 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第42期5334-5339,共6页
AIM:To investigate the association of fatty liver and smoking on metabolic syndrome and its components.METHODS:This cross-sectional study enrolled participants who attended annual health screening at Shin Kong Wu Ho-S... AIM:To investigate the association of fatty liver and smoking on metabolic syndrome and its components.METHODS:This cross-sectional study enrolled participants who attended annual health screening at Shin Kong Wu Ho-Su Memorial Hospital from January to December 2005.A total of 3455(1981 men and 1474 women) subjects were included in final analyses.Fatty liver was diagnosed using abdominal ultrasonography by trained gastroenterologists.The modified National Cholesterol Education Program Adult Treatment Panel Ⅲ was used to define metabolic syndrome.The associations between smoking,fatty liver and metabolic syndrome were analyzed using multiple logistic regression.RESULTS:Subjects with fatty liver,and who smoked tobacco,had the highest odds ratios(ORs) for high waist circumference [OR,4.5(95% CI:3.3-6.1) ,P < 0.05],hypertriglyceridemia [OR,8.1(95% CI:6.0-10.9) ,P < 0.05],low serum high-density lipoprotein cholesterol(HDL-C) [OR,8.3(95% CI:6.1-11.3) ,P < 0.05],and metabolic syndrome [OR,9.5(95% CI:6.7-13.4) ,P < 0.05] compared to subjects without fatty liver who did not smoke tobacco.We also found that the ORs for hypertriglyceridemia,low serum HDL-C,and metabolic syndrome for subjects with fatty liver who smoked tobacco had greater than the sum of the ORs for subjects with fatty liver who did not smokeplus those who did not have fatty liver and who did smoke.CONCLUSION:Fatty liver and smoking had a synergistic effect on metabolic syndrome and its components,especially for hypertriglyceridemia and low serum HDL-C. 展开更多
关键词 SMOKING Fatty liver Synergistic effect Metabolic syndrome
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A Robust Collaborative Recommendation Algorithm Based on k-distance and Tukey M-estimator 被引量:6
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作者 YI Huawei ZHANG Fuzhi LAN Jie 《China Communications》 SCIE CSCD 2014年第9期112-123,共12页
The existing collaborative recommendation algorithms have lower robustness against shilling attacks.With this problem in mind,in this paper we propose a robust collaborative recommendation algorithm based on k-distanc... The existing collaborative recommendation algorithms have lower robustness against shilling attacks.With this problem in mind,in this paper we propose a robust collaborative recommendation algorithm based on k-distance and Tukey M-estimator.Firstly,we propose a k-distancebased method to compute user suspicion degree(USD).The reliable neighbor model can be constructed through incorporating the user suspicion degree into user neighbor model.The influence of attack profiles on the recommendation results is reduced through adjusting similarities among users.Then,Tukey M-estimator is introduced to construct robust matrix factorization model,which can realize the robust estimation of user feature matrix and item feature matrix and reduce the influence of attack profiles on item feature matrix.Finally,a robust collaborative recommendation algorithm is devised by combining the reliable neighbor model and robust matrix factorization model.Experimental results show that the proposed algorithm outperforms the existing methods in terms of both recommendation accuracy and robustness. 展开更多
关键词 shilling attacks robust collaborative recommendation matrix factori-zation k-distance Tukey M-estimator
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Regional Evolution Features and Coordinated Development Strategies for Northeast China 被引量:2
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作者 MEI Lin XU Xiaopo CHEN Mingxiu 《Chinese Geographical Science》 SCIE CSCD 2006年第4期378-382,共5页
Northeast China, as the most important production base of agriculture, forestry, and livestock-breeding as well as the old industrial base in the whole country, has been playin a key role in the construction and deve... Northeast China, as the most important production base of agriculture, forestry, and livestock-breeding as well as the old industrial base in the whole country, has been playin a key role in the construction and development of China's economy. However, after the policy of reform and open-up was taken in China. the economic development speed and efficiency ofthis area have turned to be evidently lower than those of coastal area and the national average level as well, which is so-called 'Northeast Phenomenon' and 'Neo-Northeast Phenomenon'. In terms of those phenomena, this paper firstly reviews the spatial and temporal features of the regional evolution of this area so as to unveil the profound forming causes of 'Northeast Phenomena' and 'Neo-Northeast Phenomena'. And then the paper makes a further exploration into the status quo of this region and its forming causes by analyzing its economy gross, industrial structure, product structure, regional eco-categories, etc. At the end of the paper, the authors put forward the basic coordinated development strategies for Northeast China. namely we can revitalize this area by means of adjustment of economic structure, regional coordination, planning urban and rural areas as a whole, institutional innovation, etc. 展开更多
关键词 regional evolution spatial-temporal feature coordinated development strategy Northeast China
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Coordinated optimization setting of reagent dosages in roughing-scavenging process of antimony flotation 被引量:3
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作者 CAO Bin-fang XIE Yong-fang +2 位作者 GUI Wei-hua YANG Chun-hua LI Jian-qi 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第1期95-106,共12页
Considering the influence of reagent adjustment in different flotation bank on the final production index and the difficulty of establishing an effective mathematical model,a coordinated optimization method for dosage... Considering the influence of reagent adjustment in different flotation bank on the final production index and the difficulty of establishing an effective mathematical model,a coordinated optimization method for dosage reagent based on key characteristics variation tendency and case-based reasoning is proposed.On the basis of the expert reagent regulation method in antimony flotation process,the reagent dosage pre-setting model of the roughing–scavenging bank is constructed based on case-based reasoning.Then,the sensitivity index is used to calculate the key features of reagent dosage.The reagent dosage compensation model is constructed based on the variation tendency of the key features in the roughing and scavenging process.At last,the prediction model is used to finish the classification and discriminant analysis.The simulation results and industrial experiment in antimony flotation process show that the proposed method reduces fluctuation of the tailings indicators and the cost of reagent dosage.It can lay a foundation for optimizing the whole process of flotation. 展开更多
关键词 froth flotation image features optimization setting coordinated optimization
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Covariant Helicity Amplitude Analysis for J/ψ→γPP
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作者 WuNing RUANTu-Nan 《Communications in Theoretical Physics》 SCIE CAS CSCD 2001年第5期547-552,共6页
Covariant helicity amplitude analysis for the process of J/ψ →γPP is discussed.Starting from the S- matrix elements of decay process,we deduce the formulae of helicity coupling amplitudes for two-body decay process... Covariant helicity amplitude analysis for the process of J/ψ →γPP is discussed.Starting from the S- matrix elements of decay process,we deduce the formulae of helicity coupling amplitudes for two-body decay process. These formulae are used to analyze intermediate resonance states in the process of J/ψ decay to γππ,γKK,γηη' etc. 展开更多
关键词 QCD J/ψ→γPP反应 变手振幅
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Ion Pairing Kinetics Does not Necessarily Follow the Eigen-Tamm Mechanism 被引量:2
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作者 Qiang Zhang Bing-bing Zhang +1 位作者 Ling Jiang Wei Zhuang 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2013年第6期694-700,I0004,共8页
The most recognized and employed model of the solvation equilibration in the ionic solutions was proposed by Eigen and Tamm, in which there are four major states for an ion pair in the solution: the completely solvat... The most recognized and employed model of the solvation equilibration in the ionic solutions was proposed by Eigen and Tamm, in which there are four major states for an ion pair in the solution: the completely solvated state, 2SIP (double solvent separate ion pair), SIP (single solvent separate ion pair), and CIP (contact ion pair). Eigen and Tamm suggested that the transition from SIP to CIP is always the slowest step during the whole pairing process, due to a high free energy barrier between these two states. We carried out a series of potential of mean force calculations to study the pairing free energy profiles of two sets of model mono- atomic 1:1 ion pairs 2.0:x and x:2.0. For 2.0:x pairs the free energy barrier between the SIP and CIP states is largely reduced due to the salvation shell water structure. For these pairs the SIP to CIP transition is thus not the slowest step in the ion pair formation course. This is a deviation from the Eigen-Tamm model. 展开更多
关键词 Ion pairing Eigen-Tamm model Potential of mean force
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Multi-Domain Collaborative Recommendation with Feature Selection 被引量:3
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作者 Lizhen Liu Junjun Cui +1 位作者 Wei Song Hanshi Wang 《China Communications》 SCIE CSCD 2017年第8期137-148,共12页
Collaborative f iltering, as one of the most popular techniques, plays an important role in recommendation systems. However,when the user-item rating matrix is sparse,its performance will be degenerate. Recently,domai... Collaborative f iltering, as one of the most popular techniques, plays an important role in recommendation systems. However,when the user-item rating matrix is sparse,its performance will be degenerate. Recently,domain-specific recommendation approaches have been developed to address this problem.The basic idea is to partition the users and items into overlapping domains, and then perform recommendation in each domain independently. Here, a domain means a group of users having similar preference to a group of products. However, these domain-specific methods consisting of two sequential steps ignore the mutual benefi t of domain segmentation and recommendation. Hence, a unified framework is presented to simultaneously realize recommendation and make use of the domain information underlying the rating matrix in this paper. Based on matrix factorization,the proposed model learns both user preferences of multiple domains and preference selection vectors to select relevant features for each group of products. Besides, local context information is utilized from the user-item rating matrix to enhance the new framework.Experimental results on two widely used datasets, e.g., Ciao and Epinions, demonstrate the effectiveness of our proposed model. 展开更多
关键词 collaborative recommendation multi-domain matrix factorization feature selection
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A better parameter in predicting insulin resistance:Obesity plus elevated alanine aminotransferase 被引量:2
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作者 Ping-Hao then Jong-Dar Chen Yu-Cheng Lin 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第44期5598-5603,共6页
AIM:To investigate the association of obesity and elevated alanine aminotransferase with insulin resistance and compare these factors with metabolic syndrome. METHODS:We enrolled a total of 1308 male workers aged from... AIM:To investigate the association of obesity and elevated alanine aminotransferase with insulin resistance and compare these factors with metabolic syndrome. METHODS:We enrolled a total of 1308 male workers aged from 22 to 63 years.Data was extracted from the workers'periodic health check-ups in hospitals.All cases were from the community of northern Taiwan. This was a cross-sectional observational study from July to September in 2004.We grouped all cases into four groups,based on the quartile of homeostasis model assessment.The top fourth quartile group was defined as the group with insulin resistance.We performed multivariate logistic regression analysis for the odds ratio of the risk factors for insulin resistance. RESULTS:Compared with metabolic syndrome,the coexistence of both factors had a 4.3-fold(95%CI: 2.7-6.8)increased risk,which was more than metabolic syndrome with a 3.6-fold(95%CI:2.6-5.0)increased risk.The two factors had a synergistic effect.The synergistic index of obesity and elevated alanine aminotransferase(ALT)was 2.1(95%CI:1.01-4.3).CONCLUSION:Obesity and elevated ALT are associatedwith insulin resistance.The effects are synergistic. Coexistence of them is better than metabolic syndrome in predicting insulin resistance. 展开更多
关键词 Alanine aminotransferase TRANSAMINASE OVERWEIGHT OBESITY Insulin resistance
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Altimeter significant wave height data assimilation in the South China Sea using Ensemble Optimal Interpolation
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作者 曹蕾 侯一筠 齐鹏 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第5期1309-1319,共11页
The application of ensemble optimal interpolation in wave data assimilation in the South China Sea is presented. A sampling strategy for a stationary ensemble is first discussed. The stationary ensemble is constructed... The application of ensemble optimal interpolation in wave data assimilation in the South China Sea is presented. A sampling strategy for a stationary ensemble is first discussed. The stationary ensemble is constructed by sampling from 24-h-interval significant wave height differences of model outputs over a long period,and is validated with altimeter significant wave height data,indicating that the ensemble errors have nearly the same probability distribution function. The background error covariance fields expressed by the ensemble sampled are anisotropic. Updating the static samples by season,the seasonal characteristics of the correlation coefficient distribution are reflected. Hindcast experiments including assimilation and control runs are conducted for the summer of 2010 in the South China Sea. The effect of ensemble optimal interpolation assimilation on wave hindcasts is validated using different satellite altimeter data(Jason-1 and 2 and ENVISAT) and buoy observations. It is found that the ensemble-optimal-interpolation-based wave assimilation scheme for the South China Sea achieves improvements similar to those of the previous optimal-interpolation-based scheme,indicating that the practical application of this computationally cheap ensemble method is feasible. 展开更多
关键词 ensemble optimal interpolation wave assimilation stationary ensemble
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An infrared human face recognition method based on 2DPCA
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作者 刘侠 李廷军 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第2期265-268,共4页
Aimed at the problems of infrared image recognition under varying illumination,face disguise,etc.,we bring out an infrared human face recognition algorithm based on 2DPCA.The proposed algorithm can work out the covari... Aimed at the problems of infrared image recognition under varying illumination,face disguise,etc.,we bring out an infrared human face recognition algorithm based on 2DPCA.The proposed algorithm can work out the covariance matrix of the training sample easily and directly;at the same time,it costs less time to work out the eigenvector.Relevant experiments are carried out,and the result indicates that compared with the traditional recognition algorithm,the proposed recognition method is swift and has a good adaptability to the changes of human face posture. 展开更多
关键词 infrared image face recognition feature sub-space K-L transformation
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基于手征微扰理论构建相对论重子-重子相互作用(英文)
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作者 任修磊 李凯文 耿立升 《原子核物理评论》 CSCD 北大核心 2017年第3期392-402,共11页
介绍了两个近期基于协变手征微扰理论构建领头阶核子-核子和超子-核子相互作用的工作。理论中未知的低能常数通过拟合核子-核子和超子-核子散射实验数据确定。分析发现,在对散射数据的描述上,领头阶相对论手征力可以媲美次领头阶非相对... 介绍了两个近期基于协变手征微扰理论构建领头阶核子-核子和超子-核子相互作用的工作。理论中未知的低能常数通过拟合核子-核子和超子-核子散射实验数据确定。分析发现,在对散射数据的描述上,领头阶相对论手征力可以媲美次领头阶非相对论手征核力。研究表明,构建相对论手征重子-重子相互作用技术上是可行的。得到的相互作用不仅可以为相对论核结构及反应研究提供重要的理论输入,而且可以进一步加深对低能强相互作用的认识。 展开更多
关键词 核子-核子相互作用 超子-核子相互作用 变手微扰理论
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mRNA enrichment protocols determine the quantification characteristics of external RNA spike-in controls in RNA-Seq studies 被引量:4
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作者 QING Tao YU Ying +1 位作者 DU TingTing SHI LeMing 《Science China(Life Sciences)》 SCIE CAS 2013年第2期134-142,共9页
RNA-Seq promises to be used in clinical settings as a gene-expression profiling tool;however,questions about its variability and biases remain and need to be addressed.Thus,RNA controls with known concentrations and s... RNA-Seq promises to be used in clinical settings as a gene-expression profiling tool;however,questions about its variability and biases remain and need to be addressed.Thus,RNA controls with known concentrations and sequence identities originally developed by the External RNA Control Consortium(ERCC) for microarray and qPCR platforms have recently been proposed for RNA-Seq platforms,but only with a limited number of samples.In this study,we report our analysis of RNA-Seq data from 92 ERCC controls spiked in a diverse collection of 447 RNA samples from eight ongoing studies involving five species(human,rat,mouse,chicken,and Schistosoma japonicum) and two mRNA enrichment protocols,i.e.,poly(A) and RiboZero.The entire collection of datasets consisted of 15650143175 short sequence reads,131603796(i.e.,0.84%) of which were mapped to the 92 ERCC references.The overall ERCC mapping ratio of 0.84% is close to the expected value of 1.0% when assuming a 2.0% mRNA fraction in total RNA,but showed a difference of 2.8-fold across studies and 4.3-fold among samples from the same study with one tissue type.This level of fluctuation may prevent the ERCC controls from being used for cross-sample normalization in RNA-Seq.Furthermore,we observed striking biases of quantification between poly(A) and RiboZero which are transcript-specific.For example,ERCC-00116 showed a 7.3-fold under-enrichment in poly(A) compared to RiboZero.Extra care is needed in integrative analysis of multiple datasets and technical artifacts of protocol differences should not be taken as true biological findings. 展开更多
关键词 RNA-SEQ External RNA Control Consortium (ERCC) MAQC/SEQC mRNA enrichment protocol quality control reproducibility quantification bias poly(A) versus RiboZero
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Covert voice over internet protocol communications based on spatial model 被引量:3
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作者 HUANG YongFeng TANG ShanYu 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2016年第1期117-127,共11页
This paper presents a new spatial steganography model for covert communications over voice over internet protocol(Vo IP), providing a solution to the issue of increasing the capacity of covert Vo IP channels without c... This paper presents a new spatial steganography model for covert communications over voice over internet protocol(Vo IP), providing a solution to the issue of increasing the capacity of covert Vo IP channels without compromising the imperceptibility of the channels. Drawing from Orthogonal Modulation Theory in communications, the model introduced two concepts, orthogonal data hiding features and data hiding vectors, to covert Vo IP communications. By taking into account the variation characteristics of Vo IP audio streams in the time domain, a hiding vector negotiation mechanism was suggested to achieve dynamic self-adaptive steganography in media streams. Experimental results on Vo IP steganography show that the proposed steganographic method effectively depicted the spatial and temporal characteristics of Vo IP audio streams, and enhanced robustness against detection of steganalysis tools, thereby improving the security of covert Vo IP communications. 展开更多
关键词 covert communication multimedia networking Vo IP data security
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ON ASYMPTOTIC JOINT DISTRIBUTIONS OF EIGENVALUES OF RANDOM MATRICES WHICH ARISE FROM COMPONENTS OF COVARIANCE MODEL
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作者 CUIWenquan ZHAOLincheng BAIZhidong 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2005年第1期126-135,共10页
In this paper, the authors derive the asymptotic joint distributions of theeigenvalues of some random matrices which arise from components of covariance model.
关键词 Component of covariance model eigenstructure analysis limiting distribution random matrix.
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Coordination control strategy based on characteristic model for 3-bearing swivel duct nozzles 被引量:4
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作者 WANG Xiang Yang ZHU Ji Hong +1 位作者 YANG Jia Li LIU Kai 《Science China(Technological Sciences)》 SCIE EI CAS 2014年第12期2347-2356,共10页
A coordination control strategy is developed for 3-bearing swivel duct (3BSD) nozzles. A 3BSD nozzle's deflection angle and direction are changed through rotations of three revolute pairs. There is a nonlinear rela... A coordination control strategy is developed for 3-bearing swivel duct (3BSD) nozzles. A 3BSD nozzle's deflection angle and direction are changed through rotations of three revolute pairs. There is a nonlinear relationship between the deflection an- gle/direction and the rotation angles. The rotation speed of a revolute pair is limited by the power of the actuator. The moment of inertia and the aerodynamic load for each revolute pair are different and time-varying. A high-precision control system of 3BSD nozzles is required for applications on vertical and/or short take-off and landing (V/STOL) aircrafts. Difficulties of co- ordination control of 3BSD nozzles are distinct travel ranges, speed constraints, time^xarying dynamic models, and disturb- ances. The proposed control strategy is a combination of the characteristic model and tlF e dynamic control allocation method. A dynamic control allocation module is used as the coordination supervisor, which is aware of the kinematic model, the con- straints, and the dynamic models of the revolute pairs. Second-order characteristic models are used to represent the dynamic behavior of the revolute pairs. The gradient projection algorithm is modified for parameter estimation. A modified all-coefficient adaptive controller is developed to reject the disturbances. Experimental results of a scaled 3BSD nozzle indi- cate that the coordination control strategy is effective. 展开更多
关键词 3-bearing swivel duct nozzle thrust vector coordination control characteristic model adaptive control dynamic con-trol allocation
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