Turbo code has drawn more and more attractions for high data rate transmission these years especially in W CDMA and CDMA2000 of the third generation mobile communications systems. In this paper, the simulation perfor...Turbo code has drawn more and more attractions for high data rate transmission these years especially in W CDMA and CDMA2000 of the third generation mobile communications systems. In this paper, the simulation performance of turbo code under Rayleigh fading channel and additive white Gaussian channels are depicted. Comparison with the performance of convolutional code are made respect to different parameters, such as pilot length, interleaver size, frame length, mobile velocity and data rate, etc. Faithful results are drawn out.展开更多
Timing and carrier frequency offset estimation are critical issue for OFDM cooperative communications. In view of the complexity and high accuracy requirement, 1/2 and 1/4 pilot symbol cycle CAZAC sequence structures ...Timing and carrier frequency offset estimation are critical issue for OFDM cooperative communications. In view of the complexity and high accuracy requirement, 1/2 and 1/4 pilot symbol cycle CAZAC sequence structures are defined as the pilot frequency sequence. Estimation within one symbol cycle is carried out through averaging samples of two neighboring symbol cycles, after which the operation is expanded to all the symbol cycles in one band group. Taking multipath effect into account, the concept of phase rotation is proposed for a further step. Adjust the phase difference of estimated symbols by phase rotation, and cross estimation could be done. Meanwhile, timing scheme works within one cycle training sequence. Theoretical and simulation analysis indicate that CRLB does not only relate to estimation symbol length, but also be influenced by phase difference of estimation symbols seriously. In the condition that the length of estimation is fixed, the bigger the phase rotation angle is, the smaller the CRLB is. The complexity of proposed algorithm is less than full cycle average estimation method for almost 50%. Meanwhile, the estimation accuracy is approximate with the full cycle average estimation method as well. Timing scheme with the defined preamble structure is also proposed. Simulation proves its efficiency.展开更多
Based on the driver surveillance video data and controller area network(CAN)data,the methods of studying commercial vehicles’driving behavior is relatively advanced.However,these methods have difficulty in covering p...Based on the driver surveillance video data and controller area network(CAN)data,the methods of studying commercial vehicles’driving behavior is relatively advanced.However,these methods have difficulty in covering private vehicles.Naturalistic driving studies have disadvantages of small sample size and high cost,one new driving behavior evaluation method using massive vehicle trajectory data is put forward.An automatic encoding machine is used to reduce the noise of raw data,and then driving dynamics and self-organizing mapping(SOM)classification are used to give thresholds or the judgement method of overspeed,rapid speed change,rapid turning and rapid lane changing.The proportion of different driving behaviors and typical dangerous driving behaviors is calculated,then the temporal and spatial distribution of drivers’driving behavior and the driving behavior characteristics on typical roads are analyzed.Driving behaviors on accident-prone road sections and normal road sections are compared.Results show that in Shenzhen,frequent lane changing and overspeed are the most common unsafe driving behaviors;16.1%drivers have relatively aggressive driving behavior;the proportion of dangerous driving behavior is higher outside the original economic special zone;dangerous driving behavior is highly correlated with traffic accident frequency.展开更多
The paper reports on a study of young L2 （second language） English learners＇ dual code use as activated through a series of specially designed guided fantasies. The original concept of guided fantasies as a monolin...The paper reports on a study of young L2 （second language） English learners＇ dual code use as activated through a series of specially designed guided fantasies. The original concept of guided fantasies as a monolingually organised relaxation technique was extended to the area of bilingual reception and production. The goal was to examine the relationship between child imaginative faculty and a tendency to transfer understandings across the L1 （first language） and L2. The research consisted in exposing a class of I 0 nine-year-old children to eight guided fantasies expected to playfully attract their conscious attention to language properties and enable them to profit from L1 knowledge in L2 learning. The data were collected through the heuristically oriented qualitative study drawing on participant observation accompanied by field notes and recordings of student behaviours. The findings highlighted guided fantasies in their redefined form as a useful tool for encouraging young learners to rely on L 1 competence in making sense of L2 underlying principles.展开更多
The development of mobile internet and internet of things brings the vigorous developing data service, which increases need of bandwidth sharply. Operators strive to develop the data service oriented LTE(long term evo...The development of mobile internet and internet of things brings the vigorous developing data service, which increases need of bandwidth sharply. Operators strive to develop the data service oriented LTE(long term evolution)technology, especially TD-LTE (time division-LTE) technology adopting the spectral asymmetric. This paper analyzed details of TD-LTE system networking, and studied the feasibility of TD-LTE and TD-SCDMA(TD-synchronous code division multiple access) system with the same spectrum. At last, the paper provided suggestions on networking of TD-LTE system.展开更多
The chronic infection of hepatitis B virus(HBV) is closely related to the occurrence and development of hepatocellular carcinoma(HCC). Accumulated evidence has shown that HBV X protein(HBx protein) is a multifunctiona...The chronic infection of hepatitis B virus(HBV) is closely related to the occurrence and development of hepatocellular carcinoma(HCC). Accumulated evidence has shown that HBV X protein(HBx protein) is a multifunctional regulator with a crucial role in hepatocarcinogenesis. However, information on the mechanism by which HBV induces HCC is lacking. This review focuses on the pathological functions of HBx in HBV-induced hepatocarcinogenesis. As a transactivator, HBx can modulate nuclear factor kappa-light-chain-enhancer of activated B cells(NF-κB) and transcription factor AP-2. Moreover, HBx can affect regulatory non-coding RNAs(ncRNAs) including microRNAs and long ncRNAs(lncRNAs), such as miRNA-205 and highly upregulated in liver cancer(HULC), respectively. HBx is also involved in epigenetic modification, including methylation and acetylation. HBx interacts with various signal-transduction pathways, such as protein kinase B/Akt, Wnt/β-catenin, signal transducer and activator of transcription, and NF-κB pathways. Moreover, HBx affects cellular fate by shifting the balance toward cell survival. HBx may lead to the loss of apoptotic functions or directly contributes to oncogenesis by achieving transforming functions, which induce hepatocarcinogenesis. Additionally, HBx can modulate apoptosis and immune response by direct or indirect interaction with host factors. We conclude that HBx hastens the development of hepatoma.展开更多
Complex conditional statement is one of the bad code smells, which affects the quality of the code and design of software. In the proposed approach, two commonly-used design patterns for handling complex conditional s...Complex conditional statement is one of the bad code smells, which affects the quality of the code and design of software. In the proposed approach, two commonly-used design patterns for handling complex conditional statements are selected, and they are the factory method pattern and the strategy pattem. Two pattern-directed refactoring approaches based on the two design patterns are proposed. Each approach contains a refactoring opportunities identification algorithm and an automated refactoring algorithm. After parsing the abstract syntax tree generated from source code, the refactoring opportunities are identified effectively and automatically. Then, for candidate code, refactoring algorithms are executed automatically, which are used to simplify or remove complex conditional statements. By empirical analysis and quality assessment, the code after refactoring has better maintainability and extensibility, and the proposed approach for automated pattern-directed refactoring succeeds to reduce code size and complexity of classes.展开更多
Sixteen polymorphic microsatellite markers suitable for population genetic structure analysis and signal transduction coding genes variation measurement were developed for rice blast fungus, Magnaporthe grisea. Polymo...Sixteen polymorphic microsatellite markers suitable for population genetic structure analysis and signal transduction coding genes variation measurement were developed for rice blast fungus, Magnaporthe grisea. Polymorphism was evaluated by using forty-six isolates collected from diverse geographical locations （including japonica grown zone, indica grown zone） and rice varieties. Preliminary results indicated that each locus resolved multiple alleles ranging from three to fourteen. The results showed that these SSR-containing genes are also polymorphic in the nature population.展开更多
A single mammalian transcript normally encodes one protein, but the transcript of GNAS （G-protein u-subunit） contains two reading frames and produces two structurally unrelated proteins, XLas and ALEX. No other conf...A single mammalian transcript normally encodes one protein, but the transcript of GNAS （G-protein u-subunit） contains two reading frames and produces two structurally unrelated proteins, XLas and ALEX. No other confirmed GNAS-Iike dual-coding transcripts have been reported to date, even though many such candidate genes have been predicted by bioinformatics analysis. In this study, we constructed a series of vectors to test how two protein products were translated from a single transcript in vitro. The length of the ORF （open reading frame）, position of the first AUG and the Kozak motif were found to be important factors. These factors, as well as 55-bp NMD （nonsense-mediated mRNA decay） rule, were used in a bioinformatics search for candidate dual-coding transcripts. A total of 1307, 750 and 474 two-ORF-containing transcripts were found in human, mouse and rat, respectively, of which 170, 89 and 70, respectively, were found to be potential dual-coding transcripts. Most transcripts showed low conservation among species. Interestingly, dual-coding transcripts were significantly enriched for transcripts from the zinc-finger protein family, which are usually DNA-binding proteins involved in regulation of the transcription process.展开更多
In this paper, firstly, the characteristics of sheet-piled wharf construction are introduced. And then, six aspects of sheet-piled wharf construction are discussed： sheet pile, anchorage structure, guiding girder, an...In this paper, firstly, the characteristics of sheet-piled wharf construction are introduced. And then, six aspects of sheet-piled wharf construction are discussed： sheet pile, anchorage structure, guiding girder, anchor rod, backfilling behind sheet pile wall, superstructure of sheet-piled wharf etc. The construction of sheet pile involves piling on the land or piling？on？the sea, piling methods, piling patterns, guide frame, embedding sheet piles etc.展开更多
In this paper, the operation principle of laser rotary encoders is expounded and the optical quadruple frequency technology used in laser rotary encoders is explained, and the design idea of optical system in φ66 mm ...In this paper, the operation principle of laser rotary encoders is expounded and the optical quadruple frequency technology used in laser rotary encoders is explained, and the design idea of optical system in φ66 mm laser rotary encoder is mainly introduced, as well as the choice of principal devices.展开更多
文摘Turbo code has drawn more and more attractions for high data rate transmission these years especially in W CDMA and CDMA2000 of the third generation mobile communications systems. In this paper, the simulation performance of turbo code under Rayleigh fading channel and additive white Gaussian channels are depicted. Comparison with the performance of convolutional code are made respect to different parameters, such as pilot length, interleaver size, frame length, mobile velocity and data rate, etc. Faithful results are drawn out.
基金supported by the National Natural Science Foundation of China (No. 61371092 , No. 61401175)the Doctoral Fund of Ministry of Education of China (No. 20130061120062)the China Postdoctoral Science Foundation (No. 2014M551184)
文摘Timing and carrier frequency offset estimation are critical issue for OFDM cooperative communications. In view of the complexity and high accuracy requirement, 1/2 and 1/4 pilot symbol cycle CAZAC sequence structures are defined as the pilot frequency sequence. Estimation within one symbol cycle is carried out through averaging samples of two neighboring symbol cycles, after which the operation is expanded to all the symbol cycles in one band group. Taking multipath effect into account, the concept of phase rotation is proposed for a further step. Adjust the phase difference of estimated symbols by phase rotation, and cross estimation could be done. Meanwhile, timing scheme works within one cycle training sequence. Theoretical and simulation analysis indicate that CRLB does not only relate to estimation symbol length, but also be influenced by phase difference of estimation symbols seriously. In the condition that the length of estimation is fixed, the bigger the phase rotation angle is, the smaller the CRLB is. The complexity of proposed algorithm is less than full cycle average estimation method for almost 50%. Meanwhile, the estimation accuracy is approximate with the full cycle average estimation method as well. Timing scheme with the defined preamble structure is also proposed. Simulation proves its efficiency.
基金The National Natural Science Foundation of China(No.71641005)the National Key Research and Development Program of China(No.2018YFB1601105)
文摘Based on the driver surveillance video data and controller area network(CAN)data,the methods of studying commercial vehicles’driving behavior is relatively advanced.However,these methods have difficulty in covering private vehicles.Naturalistic driving studies have disadvantages of small sample size and high cost,one new driving behavior evaluation method using massive vehicle trajectory data is put forward.An automatic encoding machine is used to reduce the noise of raw data,and then driving dynamics and self-organizing mapping(SOM)classification are used to give thresholds or the judgement method of overspeed,rapid speed change,rapid turning and rapid lane changing.The proportion of different driving behaviors and typical dangerous driving behaviors is calculated,then the temporal and spatial distribution of drivers’driving behavior and the driving behavior characteristics on typical roads are analyzed.Driving behaviors on accident-prone road sections and normal road sections are compared.Results show that in Shenzhen,frequent lane changing and overspeed are the most common unsafe driving behaviors;16.1%drivers have relatively aggressive driving behavior;the proportion of dangerous driving behavior is higher outside the original economic special zone;dangerous driving behavior is highly correlated with traffic accident frequency.
文摘The paper reports on a study of young L2 （second language） English learners＇ dual code use as activated through a series of specially designed guided fantasies. The original concept of guided fantasies as a monolingually organised relaxation technique was extended to the area of bilingual reception and production. The goal was to examine the relationship between child imaginative faculty and a tendency to transfer understandings across the L1 （first language） and L2. The research consisted in exposing a class of I 0 nine-year-old children to eight guided fantasies expected to playfully attract their conscious attention to language properties and enable them to profit from L1 knowledge in L2 learning. The data were collected through the heuristically oriented qualitative study drawing on participant observation accompanied by field notes and recordings of student behaviours. The findings highlighted guided fantasies in their redefined form as a useful tool for encouraging young learners to rely on L 1 competence in making sense of L2 underlying principles.
基金Important National Science & Technology Specific Projects"New Generation Broadband Wireless Mobile Communication"2010 project"TD-LTE Large-Scale Technical Trial "( No. 2010ZX03002-009)
文摘The development of mobile internet and internet of things brings the vigorous developing data service, which increases need of bandwidth sharply. Operators strive to develop the data service oriented LTE(long term evolution)technology, especially TD-LTE (time division-LTE) technology adopting the spectral asymmetric. This paper analyzed details of TD-LTE system networking, and studied the feasibility of TD-LTE and TD-SCDMA(TD-synchronous code division multiple access) system with the same spectrum. At last, the paper provided suggestions on networking of TD-LTE system.
文摘The chronic infection of hepatitis B virus(HBV) is closely related to the occurrence and development of hepatocellular carcinoma(HCC). Accumulated evidence has shown that HBV X protein(HBx protein) is a multifunctional regulator with a crucial role in hepatocarcinogenesis. However, information on the mechanism by which HBV induces HCC is lacking. This review focuses on the pathological functions of HBx in HBV-induced hepatocarcinogenesis. As a transactivator, HBx can modulate nuclear factor kappa-light-chain-enhancer of activated B cells(NF-κB) and transcription factor AP-2. Moreover, HBx can affect regulatory non-coding RNAs(ncRNAs) including microRNAs and long ncRNAs(lncRNAs), such as miRNA-205 and highly upregulated in liver cancer(HULC), respectively. HBx is also involved in epigenetic modification, including methylation and acetylation. HBx interacts with various signal-transduction pathways, such as protein kinase B/Akt, Wnt/β-catenin, signal transducer and activator of transcription, and NF-κB pathways. Moreover, HBx affects cellular fate by shifting the balance toward cell survival. HBx may lead to the loss of apoptotic functions or directly contributes to oncogenesis by achieving transforming functions, which induce hepatocarcinogenesis. Additionally, HBx can modulate apoptosis and immune response by direct or indirect interaction with host factors. We conclude that HBx hastens the development of hepatoma.
文摘Complex conditional statement is one of the bad code smells, which affects the quality of the code and design of software. In the proposed approach, two commonly-used design patterns for handling complex conditional statements are selected, and they are the factory method pattern and the strategy pattem. Two pattern-directed refactoring approaches based on the two design patterns are proposed. Each approach contains a refactoring opportunities identification algorithm and an automated refactoring algorithm. After parsing the abstract syntax tree generated from source code, the refactoring opportunities are identified effectively and automatically. Then, for candidate code, refactoring algorithms are executed automatically, which are used to simplify or remove complex conditional statements. By empirical analysis and quality assessment, the code after refactoring has better maintainability and extensibility, and the proposed approach for automated pattern-directed refactoring succeeds to reduce code size and complexity of classes.
文摘Sixteen polymorphic microsatellite markers suitable for population genetic structure analysis and signal transduction coding genes variation measurement were developed for rice blast fungus, Magnaporthe grisea. Polymorphism was evaluated by using forty-six isolates collected from diverse geographical locations （including japonica grown zone, indica grown zone） and rice varieties. Preliminary results indicated that each locus resolved multiple alleles ranging from three to fourteen. The results showed that these SSR-containing genes are also polymorphic in the nature population.
文摘A single mammalian transcript normally encodes one protein, but the transcript of GNAS （G-protein u-subunit） contains two reading frames and produces two structurally unrelated proteins, XLas and ALEX. No other confirmed GNAS-Iike dual-coding transcripts have been reported to date, even though many such candidate genes have been predicted by bioinformatics analysis. In this study, we constructed a series of vectors to test how two protein products were translated from a single transcript in vitro. The length of the ORF （open reading frame）, position of the first AUG and the Kozak motif were found to be important factors. These factors, as well as 55-bp NMD （nonsense-mediated mRNA decay） rule, were used in a bioinformatics search for candidate dual-coding transcripts. A total of 1307, 750 and 474 two-ORF-containing transcripts were found in human, mouse and rat, respectively, of which 170, 89 and 70, respectively, were found to be potential dual-coding transcripts. Most transcripts showed low conservation among species. Interestingly, dual-coding transcripts were significantly enriched for transcripts from the zinc-finger protein family, which are usually DNA-binding proteins involved in regulation of the transcription process.
文摘In this paper, firstly, the characteristics of sheet-piled wharf construction are introduced. And then, six aspects of sheet-piled wharf construction are discussed： sheet pile, anchorage structure, guiding girder, anchor rod, backfilling behind sheet pile wall, superstructure of sheet-piled wharf etc. The construction of sheet pile involves piling on the land or piling？on？the sea, piling methods, piling patterns, guide frame, embedding sheet piles etc.
文摘In this paper, the operation principle of laser rotary encoders is expounded and the optical quadruple frequency technology used in laser rotary encoders is explained, and the design idea of optical system in φ66 mm laser rotary encoder is mainly introduced, as well as the choice of principal devices.
