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SYNTHESIS AND AVERAGE SEQUENCE LENGTH DETERMINATION OF AROMATIC-ALIPHATIC COPOLYESTERS CONTAINING POLY(ALKYLENE OXALATE)UNITS 被引量:1
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作者 赵蕴慧 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2008年第2期221-229,共9页
Two series of aromatic-aliphatic random copolyesters(PEBTOXS)with diverse diol ratios have been synthesized by direct melting polycondensation.Two kinds of diols(glycol(EG)and 1,4-butanediol(BD))are used in combinatio... Two series of aromatic-aliphatic random copolyesters(PEBTOXS)with diverse diol ratios have been synthesized by direct melting polycondensation.Two kinds of diols(glycol(EG)and 1,4-butanediol(BD))are used in combination in order to adjust crystallization and tensile properties,and three kinds of diacids(dimethyl terephthalate(DMT),diethyl oxalate(DEOX),and sebacic acid(SA))are involved.~1H-NMR spectra quantify both composition and structure,and show that the final contents in copolyesters appropriate to the ... 展开更多
关键词 Poly(alkylene oxalate) COPOLYESTER SYNTHESIS average sequence length.
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Average Run Length in TEWMA Control Charts:Analytical Solutions for AR(p)Processes and Real Data Applications
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作者 Sirawit Makaew Yupaporn Areepong Saowanit Sukparungsee 《Computer Modeling in Engineering & Sciences》 2025年第5期1617-1634,共18页
This study aims to examine the explicit solution for calculating the Average Run Length(ARL)on the triple exponentially weighted moving average(TEWMA)control chart applied to autoregressive model(AR(p)),where AR(p)is ... This study aims to examine the explicit solution for calculating the Average Run Length(ARL)on the triple exponentially weighted moving average(TEWMA)control chart applied to autoregressive model(AR(p)),where AR(p)is an autoregressive model of order p,representing a time series with dependencies on its p previous values.Additionally,the study evaluates the accuracy of both explicit and numerical integral equation(NIE)solutions for AR(p)using the TEWMA control chart,focusing on the absolute percentage relative error.The results indicate that the explicit and approximate solutions are in close agreement.Furthermore,the study investigates the performance of exponentially weighted moving average(EWMA)and TEWMA control charts in detecting changes in the process,using the relative mean index(RMI)as a measure.The findings demonstrate that the TEWMA control chart outperforms the EWMA control chart in detecting process changes,especially when the value ofλis sufficiently large.In addition,an analysis using historical data from the SET index between January 2024 and May 2024 and historical data of global annual plastic production,the results of both data sets also emphasize the superior performance of the TEWMA control chart. 展开更多
关键词 EWMA control chart TEWMA control charts average run length shift detection explicit formula Fredholm integral equation Banach’s fixed-point theorem AR(p)process
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Length matters:Scalable fast encrypted internet traffic service classification based on multiple protocol data unit length sequence with composite deep learning 被引量:4
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作者 Zihan Chen Guang Cheng +3 位作者 Ziheng Xu Shuyi Guo Yuyang Zhou Yuyu Zhao 《Digital Communications and Networks》 SCIE CSCD 2022年第3期289-302,共14页
As an essential function of encrypted Internet traffic analysis,encrypted traffic service classification can support both coarse-grained network service traffic management and security supervision.However,the traditio... As an essential function of encrypted Internet traffic analysis,encrypted traffic service classification can support both coarse-grained network service traffic management and security supervision.However,the traditional plaintext-based Deep Packet Inspection(DPI)method cannot be applied to such a classification.Moreover,machine learning-based existing methods encounter two problems during feature selection:complex feature overcost processing and Transport Layer Security(TLS)version discrepancy.In this paper,we consider differences between encryption network protocol stacks and propose a composite deep learning-based method in multiprotocol environments using a sliding multiple Protocol Data Unit(multiPDU)length sequence as features by fully utilizing the Markov property in a multiPDU length sequence and maintaining suitability with a TLS-1.3 environment.Control experiments show that both Length-Sensitive(LS)composite deep learning model using a capsule neural network and LS-long short time memory achieve satisfactory effectiveness in F1-score and performance.Owing to faster feature extraction,our method is suitable for actual network environments and superior to state-of-the-art methods. 展开更多
关键词 Encrypted internet traffic Encrypted traffic service classification Multi PDU length sequence length sensitive composite deep learning TLS-1.3
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Incidence trends and predictors for cost and average lengths of stay in colorectal cancer surgery 被引量:1
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作者 Daw-Shyong Perng I-Cheng Lu +4 位作者 Hon-Yi Shi Chih-Wen Lin Kuang-Wen Liu Ya-Fen Su King-Teh Lee 《World Journal of Gastroenterology》 SCIE CAS 2014年第2期532-538,共7页
AIM:To evaluate the changing trends and outcomes of colorectal cancer(CRC)surgery performed at a large single institution in Taiwan.METHODS:This study retrospectively analyzed 778patients who received colorectal cance... AIM:To evaluate the changing trends and outcomes of colorectal cancer(CRC)surgery performed at a large single institution in Taiwan.METHODS:This study retrospectively analyzed 778patients who received colorectal cancer surgery at E-Da Hospital in Taiwan from 2004 to 2009.These patients were from health examination,inpatient or emergency settings.The following attributes were analyzed in patients who had undergone CRC surgical procedures:gender,age,source,surgical type,tumor number,tumor size,number of lymph node metastasis,pathologic differentiation,chemotherapy,distant metastases,tumor site,tumor stage,average hospitalization cost and average lengths of stay(ALOS).The odds ratio and95%confidence intervals were calculated to assess the relative rate of change.Regression models were employed to predict average hospitalization cost and ALOS.RESULTS:The study sample included 458(58.87%)males and 320(41.13%)females with a mean age of64.53 years(standard deviation,12.33 years;range,28-86 years).The principal patient source came from inpatient and emergency room(96.02%).The principal tumor sites were noted at the sigmoid colon(35.73%)and rectum(30.46%).Most patients exhibited a tumor stage of 2(37.28%)or 3(34.19%).The number of new CRC surgeries performed per 100000 persons was12.21 in 2004 and gradually increased to 17.89 in 2009,representing a change of 46.52%.During the same period,the average hospitalization cost and ALOS decreased from$5303 to$4062 and from 19.7 to 14.4 d,respectively.The following factors were associated with considerably decreased hospital resource utilization:age,source,surgical type,tumor size,tumor site,and tumor stage.CONCLUSION:These results can be generalized to patient populations elsewhere in Taiwan and to other countries with similar patient profiles. 展开更多
关键词 Colorectal cancer average hospitalization cost average lengths of stay Incidence trend Colorectal cancer surgery
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Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan 被引量:1
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作者 Altaf Hussain Tiantian Wu +15 位作者 Hui Li Linjin Fan Kai Li Li Gao Yongqiang Wang Yulong Gao Changjun Liu Hongyu Cui Qing Pan Yanping Zhang Asim Aslam Khan Muti-Ur-Rehman Muhammad Munir Salman Latif Butt Xiaomei Wang Xiaole Qi 《Virologica Sinica》 SCIE CAS CSCD 2019年第1期102-105,共4页
Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segment... Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However. 展开更多
关键词 In PATHOGENIC CHARACTERIZATION and Full length Genome sequence of a REASSORTANT Infectious Bursal Disease Virus NEWLY ISOLATED in Pakistan
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Sequence-length variation of mtDNA HVS-I C-stretch in Chinese ethnic groups 被引量:1
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作者 Feng CHEN Yong-hui DANG +4 位作者 Chun-xia YAN Yan-ling LIU Ya-jun DENG David J. R. FULTON Teng CHEN 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2009年第10期711-720,共10页
The purpose of this study was to investigate mitochondrial DNA (mtDNA) hypervariable segment-I (HVS-I) C-stretch variations and explore the significance of these variations in forensic and population genetics studies.... The purpose of this study was to investigate mitochondrial DNA (mtDNA) hypervariable segment-I (HVS-I) C-stretch variations and explore the significance of these variations in forensic and population genetics studies. The C-stretch sequence variation was studied in 919 unrelated individuals from 8 Chinese ethnic groups using both direct and clone sequencing ap-proaches. Thirty eight C-stretch haplotypes were identified, and some novel and population specific haplotypes were also detected. The C-stretch genetic diversity (GD) values were relatively high, and probability (P) values were low. Additionally, C-stretch length heteroplasmy was observed in approximately 9% of individuals studied. There was a significant correlation (r=-0.961, P<0.01) between the expansion of the cytosine sequence length in the C-stretch of HVS-I and a reduction in the number of up-stream adenines. These results indicate that the C-stretch could be a useful genetic maker in forensic identification of Chinese populations. The results from the Fst and dA genetic distance matrix, neighbor-joining tree, and principal component map also suggest that C-stretch could be used as a reliable genetic marker in population genetics. 展开更多
关键词 Mitochondrial DNA (mtDNA) Clone sequencing length heteroplasmy Population genetics
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Exact Run Length Evaluation on a Two-Sided Modified ExponentiallyWeighted Moving Average Chart for Monitoring 被引量:1
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作者 Piyatida Phanthuna Yupaporn Areepong Saowanit Sukparungsee 《Computer Modeling in Engineering & Sciences》 SCIE EI 2021年第4期23-41,共19页
A modified exponentially weighted moving average (EWMA) scheme is one of the quality control charts suchthat this control chart can quickly detect a small shift. The average run length (ARL) is frequently used for the... A modified exponentially weighted moving average (EWMA) scheme is one of the quality control charts suchthat this control chart can quickly detect a small shift. The average run length (ARL) is frequently used for theperformance evaluation on control charts. This paper proposes the explicit formula for evaluating the average runlength on a two-sided modified exponentially weighted moving average chart under the observations of a first-orderautoregressive process, referred to as AR(1) process, with an exponential white noise. The performance comparisonof the explicit formula and the numerical integral technique is carried out using the absolute relative change forchecking the correct formula and the CPU time for testing speed of calculation. The results show that the ARL ofthe explicit formula and the numerical integral equation method are hardly different, but this explicit formula ismuch faster for calculating the ARL and offered accurate values. Furthermore, the cumulative sum, the classicalEWMA and the modified EWMA control charts are compared and the results show that the latter is better for smalland intermediate shift sizes. In addition, the explicit formula is successfully applied to real-world data in the healthfield as COVID-19 data in Thailand and Singapore. 展开更多
关键词 Explicit formula average run length modified EWMA chart AR(1)process exponential white noise
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The Correlation of Hospital Operational Efficiency and Average Length of Stay in China: A Study Based on Provincial Level Data 被引量:1
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作者 Qian Liu Xinyu Zhang +4 位作者 Yanan Guo Yao Zhang Yaxuan Wang Bo Li Yaogang Wang 《Journal of Biosciences and Medicines》 2016年第12期49-55,共7页
Objective: To measure the hospital operation efficiency, study the correlation between average length of stay and hospital operation efficiency, analyze the importance of shortening average length of stay to the impro... Objective: To measure the hospital operation efficiency, study the correlation between average length of stay and hospital operation efficiency, analyze the importance of shortening average length of stay to the improvement of the hospital operation efficiency and put forward relevant policy suggestion. Methods: Based on China provincial panel data from 2003 to 2012, the hospital operation efficiencies are calculated using Super Efficiency Data Envelopment Analysis model, and the correlation between average length of stay and hospital operation efficiency is tested using Spearman rank correlation coefficient test. Results: From 2003 to 2012, the average of national hospital operation efficiency was increasing slowly and the hospital operations were inefficient in most of the areas. The national hospital operation efficiency is negatively correlated to the average length of stay. Conclusion: Measures should be taken to set average length of stay in a scientific and reasonable way, improve social and economic benefits based on the improvement of efficiency. 展开更多
关键词 average length of Stay Hospital Operation Efficiency CORRELATION Super Efficiency Data Envelopment Analysis
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Generation and Analysis of Expressed Sequence Tags(ESTs) from Muscle Full-Length cDNA Library of Wujin Pig 被引量:2
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作者 ZHAO Su-mei LIU Yong-gang +4 位作者 PAN Hong-bing ZHANG Xi GE Chang-rong JIA Jun-jing GAO Shi-zheng 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2014年第2期378-386,共9页
Porcine skeletal muscle genes play a major role in determining muscle growth and meat quality. Construction of a full-length cDNA library is an effective way to understand the expression of functional genes in muscle ... Porcine skeletal muscle genes play a major role in determining muscle growth and meat quality. Construction of a full-length cDNA library is an effective way to understand the expression of functional genes in muscle tissues. In addition, novel genes for further research could be identified in the library. In this study, we constructed a full-length cDNA library from porcine muscle tissue. The estimated average size of the cDNA inserts was 1 076 bp, and the cDNA fullness ratio was 86.2%. A total of 1 058 unique sequences with 342 contigs (32.3%) and 716 singleton (67.7%) expressed sequence tags (EST) were obtained by clustering and assembling. Meanwhile, 826 (78.1%) ESTs were categorized as known genes, and 232 (21.9%) ESTs were categorized as unknown genes. 65 novel porcine genes that exhibit no identity in the TIGR gene index of Sus scrofa and 124 full-length sequences with unknown functions were deposited in the dbEST division of GenBank (accession numbers: EU650784-EU650788, GE843306, GH228978-GH229100). The abundantly expressed genes in porcine muscle tissue were related to muscle fiber development, energy metabolism and protein synthesis. Gene ontology analysis showed that sequences expressed in porcine muscle tissue contained a high percentage of binding activity, catalytic activity, structural molecule activity and motor activity, which involved mainly in metabolic, cellular and developmental process, distributed mainly in intracellular region. The sequence data generated in this study would provide valuable information for identifying porcine genes expressed in muscle tissue and help to advance the study on the structure and function of genes in pigs. 展开更多
关键词 muscle tissue full-length cDNA library expressed sequence tag PIG
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Sequence Length Limits for Controlling False Positives in Discovering Nucleotide Sequence Motifs
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作者 陈蕾 钱自亮 《Journal of Shanghai Jiaotong university(Science)》 EI 2008年第5期635-640,共6页
In the study of motif discovery, especially the transcription factor DNA binding sites discovery, a too long input sequence would return non-informative motifs rather than those biological functional motifs. This pape... In the study of motif discovery, especially the transcription factor DNA binding sites discovery, a too long input sequence would return non-informative motifs rather than those biological functional motifs. This paper gave theoretical analyses and computational experiments to suggest the length limits of the input sequence. When the sequence length exceeds a certain critical point, the probability of discovering the motif decreases sharply. The work not only gave an explanation on the unsatisfying results of the existed motif discovery problems that the input sequence length might be too long and exceed the point, but also provided an estimation of input sequence length we should accept to get more meaningful and reliable results in motif discovery. 展开更多
关键词 sequence motifs noise sequence sequence length S-CURVE
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Integral Sequences of Infinite Length Whose Terms Are Relatively Prime
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作者 Kazuyuki Hatada 《Advances in Pure Mathematics》 2013年第1期24-28,共5页
It is given in Weil and Rosenlicht ([1], p. 15) that (resp. 2) for all non-negative integers m and n with m≠n if c is any even (resp. odd) integer. In the present paper we generalize this. Our purpose is to give othe... It is given in Weil and Rosenlicht ([1], p. 15) that (resp. 2) for all non-negative integers m and n with m≠n if c is any even (resp. odd) integer. In the present paper we generalize this. Our purpose is to give other integral sequences such that G.C.D.(ym,yn)=1 for all positive integers m and n with m≠n. Roughly speaking we show the following 1) and 2). 1) There are infinitely many polynomial sequences such that G.C.D.(fm(a),fn(a))=1 for all positive integers m and n with with m≠n and infinitely many rational?integers a. 2) There are polynomial sequences such that G.C.D.(gm(a,b),gn(a,b))=1 for all positive integers m and n with m≠n and arbitrary (rational or odd) integers a and b with G.C.D.(a,b)=1. Main results of the present paper are Theorems 1 and 2, and Corollaries 3, 4 and 5. 展开更多
关键词 Relatively PRIME INTEGRAL sequenceS of INFINITE length Sets of INFINITELY Many PRIME Numbers
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A Formula of Average Path Length for Unweighted Networks
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作者 LIU Chun-Ping LIU Yu-Rong +1 位作者 HE Da-Ren ZHU Lu-Jin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第10期1017-1020,共4页
In this paper,based on the adjacency matrix of the network and its powers,the formulas are derived for theshortest path and the average path length,and an effective algorithm is presented.Furthermore,an example is pro... In this paper,based on the adjacency matrix of the network and its powers,the formulas are derived for theshortest path and the average path length,and an effective algorithm is presented.Furthermore,an example is providedto demonstrate the proposed method. 展开更多
关键词 complex network average path length adjacency matrix
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DISCUSSION ON AVERAGE GENERATION OF TWODIMENSIONAL DATA SEQUENCE IN GREY SYSTEM THEORY
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作者 PINGXue-liang ZHOURu-rong LIUSheng-lan 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2004年第4期298-303,共6页
An unequal time interval sequence or a sequence with blanks is usually completed with average generation in grey system theory. This paper discovers that there exists obvious errors when using average generation to ge... An unequal time interval sequence or a sequence with blanks is usually completed with average generation in grey system theory. This paper discovers that there exists obvious errors when using average generation to generate internal points of non-consecutive neighbours. The average generation and the preference generation of the sequence are discussed, the concave and convex properties show the status of local sequence and propose a new idea for using the status to build up the criteria of choosing generation coefficient. Compared with the general average method of the one-dimensional data sequence, the two-dimensional data sequence is defined and its average generation is discussed, and the coefficient decision method for the preference generation is presented. 展开更多
关键词 average generation grey system theory data sequence non-consecutive neighbors
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AN ALGORITHM OF LOCAL PREDICTION FOR CHAOTIC SEQUENCES WITH VARIABLE FRAME LENGTH
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作者 Li Jinlong Lin Jiayu 《Journal of Electronics(China)》 2012年第3期345-352,共8页
According to the issues that the predict errors of chaotic sequences rapidly accumulated in multi-step forecasting which affects the predict accuracy, we proposed a new predict algorithm based on local modeling with v... According to the issues that the predict errors of chaotic sequences rapidly accumulated in multi-step forecasting which affects the predict accuracy, we proposed a new predict algorithm based on local modeling with variable frame length and interpolation points. The core idea is that, using interpolation method to increase the available sample data, then modeling the chaos dynamics system with least square algorithm which based on the Bernstein polynomial to realize the forecasting. We use the local modeling method, looking for the optimum frame length and interpolation points in every frame to improve the predict peformance. The experimental results show that the proposed algorithm can improve the predictive ability effectively, decreasing the accumulation of iterative errors in multi-step prediction. 展开更多
关键词 Chaotic sequences forecasting Local modeling Variable frame length Bernstein polynomial Linear interpolation
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Cloning and Sequence Analysis of the Full-Length Genome of Japanese encephalitis virus Strain SXBJ07 Isolated from Swine
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作者 WANG Wei-hua,ZHANG Yan-ming,XU Xin-gang,XING Fu-shan and TANG Qing-hai College of Veterinary Medicine,Northwest A&F University,Yangling 712000,P.R.China 《Agricultural Sciences in China》 CSCD 2009年第11期1392-1402,共11页
A virus strain, showing cytopathic effect in BHK-21 cell, was isolated from swine brains in Shaanxi Province, China, in 2007. The isolate was confirmed as Japanese encephalitis virus (JEV) by immunofluorescence ass... A virus strain, showing cytopathic effect in BHK-21 cell, was isolated from swine brains in Shaanxi Province, China, in 2007. The isolate was confirmed as Japanese encephalitis virus (JEV) by immunofluorescence assay (IFA) and reverse transcription polymerase chain reaction (RT-PCR), and named SXBJ07. The complete nueleotide and deduced amino acid sequences of the JEV strain SXBJ07 were determined. Its single open reading frame has a total of 3 432 amino acid residues. An extensive E gene based phylogenetic analysis was performed, the result showed that SXBJ07 strain belongs to genotype I. Comparison of the SXBJ07 genomic sequence with those of the 24 fully sequenced JEV strains in published databases showed nucleotide homology ranging from 99.0 to 83.7%; amino acid homology ranged from 99.8 to 94.8%. Compared SXBJ07 with SA14-14-2 strain, the current live vaccine strain in China, the homology of amino acid in envelope gene was 97.0%; and there were amino acid substitutions in 13 sites of the active domains of E protein (E1-E411). 展开更多
关键词 Japanese encephalitis virus (JEV) full-length genome sequence analysis
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Nonlinear Relationship and Its Evolutionary Trace between Average Degree and Average Path Length of Edge Vertices of China Aviation Network Based on Complex Network
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作者 Cheng Xiangjun Chen Xumei Guo Jianyuan 《Journal of Traffic and Transportation Engineering》 2024年第5期224-237,共14页
In order to reveal the complex network characteristics and evolution principle of China aviation network,the relationship between the average degree and the average path length of edge vertices of China aviation netwo... In order to reveal the complex network characteristics and evolution principle of China aviation network,the relationship between the average degree and the average path length of edge vertices of China aviation network in 1988,1994,2001,2008 and 2015 was studied.According to the theory and method of complex network,the network system was constructed with the city where the airport was located as the network node and the airline as the edge of the network.On the basis of the statistical data,the average degree and average path length of edge vertices of China aviation network in 1988,1994,2001,2008 and 2015 were calculated.Through regression analysis,it was found that the average degree had a logarithmic relationship with the average path length of edge vertices and the two parameters of the logarithmic relationship had linear evolutionary trace. 展开更多
关键词 China aviation network complex network average degree of edge vertices average path length of edge vertices logarithmic relationship evolutionary trace
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Probability Distribution of Average Length of Node Path and Its Evolution Trace of Aviation Network of China Based on Complex Network
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作者 Cheng Xiangjun Yang Fang Li Tao 《Journal of Traffic and Transportation Engineering》 2021年第2期41-52,共12页
In order to reveal the complex network feature and its evolution principle of aviation network of China,probability distribution and its evolution trace of average length of node path of aviation network of China were... In order to reveal the complex network feature and its evolution principle of aviation network of China,probability distribution and its evolution trace of average length of node path of aviation network of China were researched according to statistics data in years 1988,1994,2001,2008 and 2015 of civil aviation of China.Floyd algorithm to calculate the path length between any two nodes of network was applied and average length of node path of aviation network was obtained according to this algorithm.It was discovered that average length of node path to other nodes had normal distribution function in each year.At meantime,the location parameter and scale parameter of normal distribution function had linear evolution trace.Airline rate was an index to describe the density of airline.It was found that average length of node path of aviation network of China evolved synchronously with airline rate and they had linear relationship. 展开更多
关键词 Aviation network of China average length of node path probability distribution evolution trace airline rate
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Nonlinear Relationship and Its Evolutionary Trace between Node Degree and Average Path Length of China Aviation Network Based on Complex Network
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作者 Cheng Xiangjun Zhang Xiaoxuan Li Yangqi 《Journal of Traffic and Transportation Engineering》 2024年第1期11-22,共12页
In order to reveal the complex network characteristics and evolution principle of China aviation network,the relationship between the node degree and the average path length of China aviation network in 1988,1994,2001... In order to reveal the complex network characteristics and evolution principle of China aviation network,the relationship between the node degree and the average path length of China aviation network in 1988,1994,2001,2008 and 2015 was studied.According to the theory and method of complex network,the network system was constructed with the city where the airport was located as the network node and the airline as the edge of the network.On the basis of the statistical data,the node average path length of China aviation network in 1988,1994,2001,2008 and 2015 was calculated.Through regression analysis,it was found that the node degree had a logarithmic relationship with the average length of node path,and the two parameters of the logarithmic relationship had linear evolutionary trace.Key word:China aviation network,complex network,node degree,average length of node path,logarithmic relationship,evolutionary trace. 展开更多
关键词 China aviation network complex network node degree average length of node path logarithmic relationship evolutionary trace.
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Analysis and identification of SCAR molecular markers associated with birch fiber length trait 被引量:1
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作者 王丹 魏志刚 +1 位作者 杨传平 刘关君 《Journal of Forestry Research》 SCIE CAS CSCD 2008年第4期288-292,共5页
The fiber length trait (FLT) of 538 individuals from nature birch population in Maorshan region, Heilongjang, China were measured, of which 100 individuals were selected as representative variety of correlated fragm... The fiber length trait (FLT) of 538 individuals from nature birch population in Maorshan region, Heilongjang, China were measured, of which 100 individuals were selected as representative variety of correlated fragments screening with random amplified polymorphism DNA (RAPD) technique. In total of 20 RAPD primers were tested through multiple regression analysis between amplified strip and the character behaviors, and a correlative segment BFLR-16 was obtained. The correlation coefficient between BFLI-16 and FLT was 0.6144, with the significant level of 1%. BFLI-16 was then cloned, sequenced and transformed into SCAR marker. The percentage of identifying long fiber birches by this SCAR was more than 92. The result indicates that the SCAR markers has high specificity for the long fiber individuals and is highly linked with the gene controlling the character of fiber length, and its existence is significantly correlative with the increase in the fiber length. 展开更多
关键词 Betula platyphylla fiber length trait random amplified polymorphism DNA sequence characterized amplified region
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星地场景下基于RM编码的OTFS系统峰均比抑制方法
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作者 宋强健 张馨月 朱立东 《中国空间科学技术(中英文)》 北大核心 2026年第1期24-35,共12页
正交时频空(Orthogonal Time Frequency Space,OTFS)调制因其在高多普勒频偏环境下的可靠传输能力,已成为低轨卫星等高动态通信场景的关键技术。然而,作为多载波调制技术,OTFS信号的高峰均功率比(Peak-to-Average Power Ratio,PAPR)易... 正交时频空(Orthogonal Time Frequency Space,OTFS)调制因其在高多普勒频偏环境下的可靠传输能力,已成为低轨卫星等高动态通信场景的关键技术。然而,作为多载波调制技术,OTFS信号的高峰均功率比(Peak-to-Average Power Ratio,PAPR)易导致功放进入非线性工作状态,产生信号失真,影响通信可靠性和稳定性。格雷互补序列因其特殊的定义,使得该序列的最大峰均比不超过3 dB。基于里德-穆勒(Reed-Muller,RM)编码与格雷互补序列之间的特殊联系,提出了一种基于RM编码的OTFS系统的峰均功率比抑制方法。在发射端,首先利用RM编码将原始比特流序列编码转换为格雷互补序列形式,再进行星座映射与OTFS调制,得到低峰均功率比的发射信号。在接收端,为了实现对这种特殊编码信号的准确译码,设计了一种两步级联译码算法,通过陪集选择译码与单项式系数译码的级联实现了对具有格雷互补序列的RM编码的纠错译码,保证了通信传输的可靠性。仿真结果表明,在低轨卫星通信场景下,该编码方法可以将OTFS系统发射信号的峰均功率比抑制在3 dB以内;相较于OFDM系统,OTFS系统具有更强的鲁棒性;两步级联译码算法实现了较高信噪比(>6 dB)下更高的传输可靠性。上述方案的提出不仅为OTFS调制技术在星地高动态通信场景中的应用提供了有力的技术支持,也为未来多载波调制信号的峰均比抑制提供了新的参考。 展开更多
关键词 峰均功率比 星地通信 里德-穆勒编码 格雷互补序列 正交时频空 级联译码
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