This paper investigates the multi-beam selection algorithms for transmit correlation channels by using statistical channel state information (SCSI) and instantaneous channel state information. Unlike the conventiona...This paper investigates the multi-beam selection algorithms for transmit correlation channels by using statistical channel state information (SCSI) and instantaneous channel state information. Unlike the conventional codebook-based transmission scheme, the proposed multi-beam selection with the single channel quality indicator (CQI) feedback (MBS- SCF) algorithm determines the preferred beam vector by exploiting the SCSI and only feeds back CQI at each timeslot. The performance of the MBS-SCF algorithm is nearly the same as that of the conventional scheme. In order to further improve the average sum rate, a novel multi-beam selection with the dual CQIs feedback (MBS-DCF) algorithm is proposed, which determines dual preferred statistical eigen- directions and feeds back dual CQIs at each timeslot. The theoretical analysis and simulation results demonstrate that the MBS-DCF algorithm can increase the multiuser diversity and multiplexing gain and exhibits a higher average sum rate.展开更多
In this paper,we develop a new and effective multiple scale and strongly directional method for identifying and suppressing ground roll based on the second generation curvelet transform.Making the best use of the curv...In this paper,we develop a new and effective multiple scale and strongly directional method for identifying and suppressing ground roll based on the second generation curvelet transform.Making the best use of the curvelet transform's strong local directional characteristics,seismic frequency bands are transformed into scale data with and without noise.Since surface waves and primary reflected waves have less overlap in the curvelet domain,we can effectively identify and separate noise.Applying this method to prestack seismic data can successfully remove surface waves and,at the same time,protect the reflected events well,particularly in the low-frequency band.This indicates that the method described in this paper is an effective and amplitude-preserving method.展开更多
[Objective]The aim of this study was to understand the role of polyamine oxidative degradation in the process of lettuce seed germination. [Method]After lettuce seed soaking treatments with aminoguanidine (AG,a speci...[Objective]The aim of this study was to understand the role of polyamine oxidative degradation in the process of lettuce seed germination. [Method]After lettuce seed soaking treatments with aminoguanidine (AG,a specific inhibitor of polyamine oxidases),seed germination rate,activities of polyamine oxidase (PAO) and diamine oxidase (DAO),change of endogenous polyamine and H2O2 content were determined. [Result]Compared with the control,AG treatment strongly inhibited the seed germination,which also had an extremely significant difference in seed germination rate after incubation for 12 h. During the seed germination,activities of PAO and DAO significantly changed,while their activities firstly increased and then decreased,then DAO and PAO reached peaks at 24 h and 48 h respectively. AG treatment was strongly inhibitory for activities of DAO and PAO,whose activities even disappeared after incubation with AG for 24 h and 36 h. During the seed germination,endogenous Put reduced sharply in the first 24 h,then reduced slowly in 24-60 h,while Spd decreased slowly in the early stage of germination,and then sharply declined after 48 h. However,Spm content was low but slightly increased,and the total polyamine gradually decreased. AG treatment could significantly increase endogenous polyamines,especially Put and Spd contents. During the seed germination,H2O2 content gradually increased,and had a peak from 36 to 48 h,then kept a high level at last. AG treatment could significantly reduce H2O2 content. [Conclusion]During the seed germination,the changes of endogenous polyamine and H2O2 content correspond with the changes of PAO and DAO activities,which indicate that there is an active polyamine metabolism of oxidative degradation during the lettuce seed germination.展开更多
Based on recent research developments in multi-objective solid transportation problem (MOSTP), this paper presents a fuzzy programming approach to determine the optimal compromise solution of MOSTP. The characteristic...Based on recent research developments in multi-objective solid transportation problem (MOSTP), this paper presents a fuzzy programming approach to determine the optimal compromise solution of MOSTP. The characteristic feature of the proposed approach is that various objectives are synthetically considered with marginal evaluation for individual objectives and global evaluation for all objectives. The decision-maker's preference is taken into account by his/her assigning weights to the objectives. With global evaluation for all objectives, a compromise programming model is formulated. As a generic aggregation operator is adopted, several solution methods proposed earlier become special cases of this approach, and the solution process also becomes more flexible and realistic. An illustrative numerical example is provided to demonstrate the approach.展开更多
The selection of the truncation level (TL) and the control of boundary effect (BE) are critical in regional geomagnetic field models that are based on data fitting. We combine Taylor and Legendre polynomials to mo...The selection of the truncation level (TL) and the control of boundary effect (BE) are critical in regional geomagnetic field models that are based on data fitting. We combine Taylor and Legendre polynomials to model geomagnetic data over China's Mainland for years 1960, 1970, 1990, and 2000. To tackle the TL and BE problems, we first determine the range of TL by calculating the root-mean-square error (RMSE) of the models. Next, we determine the optimum TL using the Akaike information criterion (AIC) and the normalized root- mean-square error (NRMSE). We use the regional anomaly addition (RAA) and the uniform addition (UA) method to add supplementary point outside the national boundary, and find that the intensities of extreme points gradually decrease and stabilize. The UA method better controls BEs over China, whereas the RAA method does a better job at smaller scales. In summary, we rely on a three-step method to determine the optimum TL and propose criteria to determine the optimum number of supplementary points.展开更多
240 14-day-old healthy and non-immune Roman chicken were randomly divided into 8 groups, including blank control group (BC group), immune control group (IC group), and immunity groups of each Chinese medicine. On ...240 14-day-old healthy and non-immune Roman chicken were randomly divided into 8 groups, including blank control group (BC group), immune control group (IC group), and immunity groups of each Chinese medicine. On the day of the first immunity, 3 d before the second immunity, the day of the second immunity and 3 d after the second immunity, high-dose concentration and low-dose concen- tration of Astragalus polysaccharide (ASP), Epimedium polysaccharide (EPP) and Isatis roots polysaccharide (IRPS) were used for the immunity groups of each Chi- nese medicine using the gavage, and 0.5 ml for each chick, and the equivalent normal saline was used for the blank control group and vaccine control group. On the 7^th, 14^th, 21^st and 28^th day after the first immunity, 10 chicken of each group were randomly got and weighed, and the antibody titer and the changes of the pro- liferation of T lymphocyte were measured. The results showed that 3 kinds of Chi- nese medicine polysaccharides all can increase the weight of chicken, improve HI antibody titer of Newcastle disease, and promote the proliferation of peripheral T lymphocyte, in which the effect of IRPS at low dosage is the best.展开更多
[Objective] This study aimed to optimize the extraction process parameters of Pu-erh tea polysaccharide. [Method] Single-factor experiment was carried out to analyze the influences of three main factors, including ext...[Objective] This study aimed to optimize the extraction process parameters of Pu-erh tea polysaccharide. [Method] Single-factor experiment was carried out to analyze the influences of three main factors, including extraction temperature, ex- traction duration and solid-liquid ratio, on the extraction yield of tea polysaccharide. Box-Behnken central composite design and response surface methodology were adopted to determine the optimal extraction process of Pu-erh tea polysaccharide. [Result] The results of response surface analysis showed that the optimal extraction process was solid-liquid ratio of 1:17, extraction temperature of 80 ℃ and extraction duration of 78.5 min, and the Pu-erh tea polysaccharide yield was 12.72%. [Conclu- sion] Using response surface methodology (RSM) is feasible for the optimization of Pu-erh tea polysaccharide extraction process, and the tea polysaccharide yield increased significantly.展开更多
The current portfolio model for property-liability insurance company is only single period that can not meet the practical demands of portfolio management, and the purpose of this paper is to develop a multiperiod mod...The current portfolio model for property-liability insurance company is only single period that can not meet the practical demands of portfolio management, and the purpose of this paper is to develop a multiperiod model for its portfolio problem. The model is a multistage stochastic programming which considers transaction costs, cash flow between time periods, and the matching of asset and liability; it does not depend on the assumption for normality of return distribution. Additionally, an investment constraint is added. The numerical example manifests that the multiperiod model can more effectively assist the property-liability insurer to determine the optimal composition of insurance and investment portfolio and outperforms the single period one.展开更多
There is another way for new species to invade former settlers' habitats and successfully settle there; it is demonstrated that the su- per-population, which plays a key role in changing the world-wide environment, c...There is another way for new species to invade former settlers' habitats and successfully settle there; it is demonstrated that the su- per-population, which plays a key role in changing the world-wide environment, can create many new microhabitats in the old habitat, it is these new microhabitats that make new species easily come into the old habitat and settle there without fierce competition with former settlers. In other words, the super-population lead to the differentiation of the worldwide environment, lead to the environmental diversity in the biosphere. Through the differentiation of the environment the super-population produces many new microhabitats for new species, the appearance of many new microhabitats make it possible for new species to coexist with former settlers in the biosphere. The cqexistence of new species with former settlers or with new species' "ancestors" results in the increaseing in the biodiversity of the biosphere. The super-population is the founder of many new environments on the earth, it bridges the habitat diversity and the biodiversity. Now It is easy to explain the phenomenon that new species sometimes coexist with former settlers and even depend on former settlers in the biosphere rather than fierce competition between them.展开更多
A novel nonlinear multi-input multi-output MIMO detection algorithm is proposed which is referred to as an ordered successive noise projection cancellation OSNPC algorithm. It is capable of improving the computation p...A novel nonlinear multi-input multi-output MIMO detection algorithm is proposed which is referred to as an ordered successive noise projection cancellation OSNPC algorithm. It is capable of improving the computation performance of the MIMO detector with the conventional ordered successive interference cancellation OSIC algorithm. In contrast to the OSIC in which the known interferences in the input signal vector are successively cancelled the OSNPC successively cancels the known noise projections from the decision statistic vector. Analysis indicates that the OSNPC is equivalent to the OSIC in error performance but it has significantly less complexity in computation.Furthermore when the OSNPC is applied to the MIMO detection with the preprocessing of dual lattice reduction DLR the computational complexity of the proposed OSNPC-based DLR-aided detector is further reduced due to the avoidance of the inverse of the reduced basis of the dual lattice in computation compared to that of the OSIC-based one. Simulation results validate the theoretical conclusions with regard to both the performance and complexity of the proposed MIMO detection scheme.展开更多
An algorithm for partitioning arbitrary simple polygons into a number of convex parts was presented. The concave vertices were determined first, and then they were moved by using the method connecting the concave vert...An algorithm for partitioning arbitrary simple polygons into a number of convex parts was presented. The concave vertices were determined first, and then they were moved by using the method connecting the concave vertices with the vertices of falling into its region B,so that the primary polygon could be partitioned into two subpolygons. Finally, this method was applied recursively to the subpolygons until all the concave vertices were removed. This algorithm partitions the polygon into O(l) convex parts, its time complexity is max(O(n),O(l 2)) multiplications, where n is the number of vertices of the polygon and l is the number of the concave vertices.展开更多
A method for the multi target locating and tracking with the multi sensor in a field artillery system is studied. A general modeling structure of the system is established. Based on concepts of cluster and closed ba...A method for the multi target locating and tracking with the multi sensor in a field artillery system is studied. A general modeling structure of the system is established. Based on concepts of cluster and closed ball, an algorithm is put forward for multi sensor multi target data fusion and an optimal solution for state estimation is presented. The simulation results prove the algorithm works well for the multi stationary target locating and the multi moving target tracking under the condition of the sparse target environment. Therefore, this method can be directly applied to the field artillery C 3I system.展开更多
Due to not requiring channel state information (CSI) at both the transmitter and the receiver, noncoherent ultra-wideband (UWB) incurs a performance penalty of approximately 3 dB in the required signal to noise ra...Due to not requiring channel state information (CSI) at both the transmitter and the receiver, noncoherent ultra-wideband (UWB) incurs a performance penalty of approximately 3 dB in the required signal to noise ratio (SNR) compared to the coherent case. To overcome the gap, an effective differential encoding and decoding scheme for multiband UWB systems is proposed. The proposed scheme employs the parallel concatenation of two recursive differential unitary space-frequency encoders at the transmitter. At the receiver, two component decoders iteratively decode information bits by interchanging soft metric values between each other. To reduce the computation complexity, a decoding algorithm which only uses transition probability to calculate the log likelihood ratios (LLRs) for the decoded bits is given. Simulation results show that the proposed scheme can dramatically outperform the conventional differential and even coherent detection at high SNR with a few iterations.展开更多
The performance of multi-user code to direct spreading bi-phase shift keying (DS-BPSK) direct impulse ultra wideband (UWB) systems under indoor multi-user and multi-path environment is analyzed and simulated. The ...The performance of multi-user code to direct spreading bi-phase shift keying (DS-BPSK) direct impulse ultra wideband (UWB) systems under indoor multi-user and multi-path environment is analyzed and simulated. The system output signals with Rake receiver are derived, then a simple and practical code selection scheme is given; i. e., with a large occupation to empty ratio of the repeating pulses, directly choosing those random or pseudo-random user codes with enough length and good co-relative orthogonal features will make the performance of DS-BPSK approximate the optimum and, so there is no need to carefully design the code or its type. The system multi-access performances are simulated using Gold sequence and PN codes as multi-user codes under CMI-CM4 multi-path channels. Simulation results prove that the proposed scheme is feasible.展开更多
There were quite abundant prototypical ethnic cultures and plant diversity in Qiandongnan ( Southeast of Guizhou) ,where the primitive natural ecology was also perfectly conserved. It was honored by World Native Cul...There were quite abundant prototypical ethnic cultures and plant diversity in Qiandongnan ( Southeast of Guizhou) ,where the primitive natural ecology was also perfectly conserved. It was honored by World Native Culture Fund as One of the Eighteen Ecological and Cultural Conservations in the World. The prototypical ethnic culture of Southeast of Guizhou, as a stable life-style and economic culture type of the local people, came into being in the process of the local minorities' communicating, blending and struggling against the natural environment in the long course of history. It could be seen from this research that there were our preliminary research that there are quite abundant resources in Southeast of Guizhou in terms of prototypical ethnic cultures and genetic diversity of glutinous rice. A full reflection of the culture of Glutinous Rice could be seen in the local minority people's daily life, production, custom, religious belief, etc. These showed that the formation and great vitality of the genetic diversity of glutinous rice was not only determined by the diversity of local prototypical ethnic cultures but also to its own biotic condition and its adaptation to natural ecology. It was showed that prototypical ethnic cultures had positive impact on the conservation and utilization of Glutinous Rice diversity.展开更多
基金The National Natural Science Foundation of China( No. 60925004, 60902009, 61001103)the National Science and Technology Major Project of China ( No. 2009ZX03003-005-02, 2009ZX03003-011-04,2011ZX03003-003-03) +1 种基金the Natural Science Foundation of Jiangsu Province of China ( No. BK2011019)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China ( No. 10KJB510021)
文摘This paper investigates the multi-beam selection algorithms for transmit correlation channels by using statistical channel state information (SCSI) and instantaneous channel state information. Unlike the conventional codebook-based transmission scheme, the proposed multi-beam selection with the single channel quality indicator (CQI) feedback (MBS- SCF) algorithm determines the preferred beam vector by exploiting the SCSI and only feeds back CQI at each timeslot. The performance of the MBS-SCF algorithm is nearly the same as that of the conventional scheme. In order to further improve the average sum rate, a novel multi-beam selection with the dual CQIs feedback (MBS-DCF) algorithm is proposed, which determines dual preferred statistical eigen- directions and feeds back dual CQIs at each timeslot. The theoretical analysis and simulation results demonstrate that the MBS-DCF algorithm can increase the multiuser diversity and multiplexing gain and exhibits a higher average sum rate.
基金the Natural Science Foundation(Grant No.40739908)National Basic Research Program of China(973 Program)(Grant No.2007CB209605).
文摘In this paper,we develop a new and effective multiple scale and strongly directional method for identifying and suppressing ground roll based on the second generation curvelet transform.Making the best use of the curvelet transform's strong local directional characteristics,seismic frequency bands are transformed into scale data with and without noise.Since surface waves and primary reflected waves have less overlap in the curvelet domain,we can effectively identify and separate noise.Applying this method to prestack seismic data can successfully remove surface waves and,at the same time,protect the reflected events well,particularly in the low-frequency band.This indicates that the method described in this paper is an effective and amplitude-preserving method.
基金Supported by Doctorate Fund of Suzhou University (13120740)~~
文摘[Objective]The aim of this study was to understand the role of polyamine oxidative degradation in the process of lettuce seed germination. [Method]After lettuce seed soaking treatments with aminoguanidine (AG,a specific inhibitor of polyamine oxidases),seed germination rate,activities of polyamine oxidase (PAO) and diamine oxidase (DAO),change of endogenous polyamine and H2O2 content were determined. [Result]Compared with the control,AG treatment strongly inhibited the seed germination,which also had an extremely significant difference in seed germination rate after incubation for 12 h. During the seed germination,activities of PAO and DAO significantly changed,while their activities firstly increased and then decreased,then DAO and PAO reached peaks at 24 h and 48 h respectively. AG treatment was strongly inhibitory for activities of DAO and PAO,whose activities even disappeared after incubation with AG for 24 h and 36 h. During the seed germination,endogenous Put reduced sharply in the first 24 h,then reduced slowly in 24-60 h,while Spd decreased slowly in the early stage of germination,and then sharply declined after 48 h. However,Spm content was low but slightly increased,and the total polyamine gradually decreased. AG treatment could significantly increase endogenous polyamines,especially Put and Spd contents. During the seed germination,H2O2 content gradually increased,and had a peak from 36 to 48 h,then kept a high level at last. AG treatment could significantly reduce H2O2 content. [Conclusion]During the seed germination,the changes of endogenous polyamine and H2O2 content correspond with the changes of PAO and DAO activities,which indicate that there is an active polyamine metabolism of oxidative degradation during the lettuce seed germination.
文摘Based on recent research developments in multi-objective solid transportation problem (MOSTP), this paper presents a fuzzy programming approach to determine the optimal compromise solution of MOSTP. The characteristic feature of the proposed approach is that various objectives are synthetically considered with marginal evaluation for individual objectives and global evaluation for all objectives. The decision-maker's preference is taken into account by his/her assigning weights to the objectives. With global evaluation for all objectives, a compromise programming model is formulated. As a generic aggregation operator is adopted, several solution methods proposed earlier become special cases of this approach, and the solution process also becomes more flexible and realistic. An illustrative numerical example is provided to demonstrate the approach.
基金supported by the National Natural Science Foundation of China(Grant Nos.41404053 and 41174165)Special Project for Meteo-Scientific Research in the Public Interest(Grant No.GYHY201306073)Natural Science Foundation of Higher Education Institutions of Jiangsu Province,China(Grant No.14KJB170012)
文摘The selection of the truncation level (TL) and the control of boundary effect (BE) are critical in regional geomagnetic field models that are based on data fitting. We combine Taylor and Legendre polynomials to model geomagnetic data over China's Mainland for years 1960, 1970, 1990, and 2000. To tackle the TL and BE problems, we first determine the range of TL by calculating the root-mean-square error (RMSE) of the models. Next, we determine the optimum TL using the Akaike information criterion (AIC) and the normalized root- mean-square error (NRMSE). We use the regional anomaly addition (RAA) and the uniform addition (UA) method to add supplementary point outside the national boundary, and find that the intensities of extreme points gradually decrease and stabilize. The UA method better controls BEs over China, whereas the RAA method does a better job at smaller scales. In summary, we rely on a three-step method to determine the optimum TL and propose criteria to determine the optimum number of supplementary points.
基金Supported by Tibet Natural Science Fund(No.ZJ2013018)"Phoenix Talent Project"of Jiangsu Agri-husbandry Vocational College~~
文摘240 14-day-old healthy and non-immune Roman chicken were randomly divided into 8 groups, including blank control group (BC group), immune control group (IC group), and immunity groups of each Chinese medicine. On the day of the first immunity, 3 d before the second immunity, the day of the second immunity and 3 d after the second immunity, high-dose concentration and low-dose concen- tration of Astragalus polysaccharide (ASP), Epimedium polysaccharide (EPP) and Isatis roots polysaccharide (IRPS) were used for the immunity groups of each Chi- nese medicine using the gavage, and 0.5 ml for each chick, and the equivalent normal saline was used for the blank control group and vaccine control group. On the 7^th, 14^th, 21^st and 28^th day after the first immunity, 10 chicken of each group were randomly got and weighed, and the antibody titer and the changes of the pro- liferation of T lymphocyte were measured. The results showed that 3 kinds of Chi- nese medicine polysaccharides all can increase the weight of chicken, improve HI antibody titer of Newcastle disease, and promote the proliferation of peripheral T lymphocyte, in which the effect of IRPS at low dosage is the best.
基金Supported by National Science and Technology Support Program of China (2007BAD58B03)~~
文摘[Objective] This study aimed to optimize the extraction process parameters of Pu-erh tea polysaccharide. [Method] Single-factor experiment was carried out to analyze the influences of three main factors, including extraction temperature, ex- traction duration and solid-liquid ratio, on the extraction yield of tea polysaccharide. Box-Behnken central composite design and response surface methodology were adopted to determine the optimal extraction process of Pu-erh tea polysaccharide. [Result] The results of response surface analysis showed that the optimal extraction process was solid-liquid ratio of 1:17, extraction temperature of 80 ℃ and extraction duration of 78.5 min, and the Pu-erh tea polysaccharide yield was 12.72%. [Conclu- sion] Using response surface methodology (RSM) is feasible for the optimization of Pu-erh tea polysaccharide extraction process, and the tea polysaccharide yield increased significantly.
文摘The current portfolio model for property-liability insurance company is only single period that can not meet the practical demands of portfolio management, and the purpose of this paper is to develop a multiperiod model for its portfolio problem. The model is a multistage stochastic programming which considers transaction costs, cash flow between time periods, and the matching of asset and liability; it does not depend on the assumption for normality of return distribution. Additionally, an investment constraint is added. The numerical example manifests that the multiperiod model can more effectively assist the property-liability insurer to determine the optimal composition of insurance and investment portfolio and outperforms the single period one.
基金Supported by Science Foundation of Chuxiong Normal University(06YJRC19)National Natural Science Foundation of China(30760040)Key Subject Construction of Chuxiong Normal University(05YJJSXK03)~~
文摘There is another way for new species to invade former settlers' habitats and successfully settle there; it is demonstrated that the su- per-population, which plays a key role in changing the world-wide environment, can create many new microhabitats in the old habitat, it is these new microhabitats that make new species easily come into the old habitat and settle there without fierce competition with former settlers. In other words, the super-population lead to the differentiation of the worldwide environment, lead to the environmental diversity in the biosphere. Through the differentiation of the environment the super-population produces many new microhabitats for new species, the appearance of many new microhabitats make it possible for new species to coexist with former settlers in the biosphere. The cqexistence of new species with former settlers or with new species' "ancestors" results in the increaseing in the biodiversity of the biosphere. The super-population is the founder of many new environments on the earth, it bridges the habitat diversity and the biodiversity. Now It is easy to explain the phenomenon that new species sometimes coexist with former settlers and even depend on former settlers in the biosphere rather than fierce competition between them.
基金The National Science and Technology Major Project(No.2012ZX03004005-003)the National Natural Science Foundation of China(No.61171081,61201175)the Innovation Technology Fund of Jiangsu Province(No.BC2012006)
文摘A novel nonlinear multi-input multi-output MIMO detection algorithm is proposed which is referred to as an ordered successive noise projection cancellation OSNPC algorithm. It is capable of improving the computation performance of the MIMO detector with the conventional ordered successive interference cancellation OSIC algorithm. In contrast to the OSIC in which the known interferences in the input signal vector are successively cancelled the OSNPC successively cancels the known noise projections from the decision statistic vector. Analysis indicates that the OSNPC is equivalent to the OSIC in error performance but it has significantly less complexity in computation.Furthermore when the OSNPC is applied to the MIMO detection with the preprocessing of dual lattice reduction DLR the computational complexity of the proposed OSNPC-based DLR-aided detector is further reduced due to the avoidance of the inverse of the reduced basis of the dual lattice in computation compared to that of the OSIC-based one. Simulation results validate the theoretical conclusions with regard to both the performance and complexity of the proposed MIMO detection scheme.
文摘An algorithm for partitioning arbitrary simple polygons into a number of convex parts was presented. The concave vertices were determined first, and then they were moved by using the method connecting the concave vertices with the vertices of falling into its region B,so that the primary polygon could be partitioned into two subpolygons. Finally, this method was applied recursively to the subpolygons until all the concave vertices were removed. This algorithm partitions the polygon into O(l) convex parts, its time complexity is max(O(n),O(l 2)) multiplications, where n is the number of vertices of the polygon and l is the number of the concave vertices.
文摘A method for the multi target locating and tracking with the multi sensor in a field artillery system is studied. A general modeling structure of the system is established. Based on concepts of cluster and closed ball, an algorithm is put forward for multi sensor multi target data fusion and an optimal solution for state estimation is presented. The simulation results prove the algorithm works well for the multi stationary target locating and the multi moving target tracking under the condition of the sparse target environment. Therefore, this method can be directly applied to the field artillery C 3I system.
基金The Higher Education Technology Foundation of Huawei Technologies Co, Ltd (NoYJCB2005016WL)
文摘Due to not requiring channel state information (CSI) at both the transmitter and the receiver, noncoherent ultra-wideband (UWB) incurs a performance penalty of approximately 3 dB in the required signal to noise ratio (SNR) compared to the coherent case. To overcome the gap, an effective differential encoding and decoding scheme for multiband UWB systems is proposed. The proposed scheme employs the parallel concatenation of two recursive differential unitary space-frequency encoders at the transmitter. At the receiver, two component decoders iteratively decode information bits by interchanging soft metric values between each other. To reduce the computation complexity, a decoding algorithm which only uses transition probability to calculate the log likelihood ratios (LLRs) for the decoded bits is given. Simulation results show that the proposed scheme can dramatically outperform the conventional differential and even coherent detection at high SNR with a few iterations.
文摘The performance of multi-user code to direct spreading bi-phase shift keying (DS-BPSK) direct impulse ultra wideband (UWB) systems under indoor multi-user and multi-path environment is analyzed and simulated. The system output signals with Rake receiver are derived, then a simple and practical code selection scheme is given; i. e., with a large occupation to empty ratio of the repeating pulses, directly choosing those random or pseudo-random user codes with enough length and good co-relative orthogonal features will make the performance of DS-BPSK approximate the optimum and, so there is no need to carefully design the code or its type. The system multi-access performances are simulated using Gold sequence and PN codes as multi-user codes under CMI-CM4 multi-path channels. Simulation results prove that the proposed scheme is feasible.
基金Supported by Natural Scientific Research Fund of Guizhou Provincial Department of Education (2007085)the Bidding Notices Fund of Aboriginal Ethnic Culture Study Center of Kaili University(YST200903 )Key Subject Fund of Botany of Kaili University(Z0603)~~
文摘There were quite abundant prototypical ethnic cultures and plant diversity in Qiandongnan ( Southeast of Guizhou) ,where the primitive natural ecology was also perfectly conserved. It was honored by World Native Culture Fund as One of the Eighteen Ecological and Cultural Conservations in the World. The prototypical ethnic culture of Southeast of Guizhou, as a stable life-style and economic culture type of the local people, came into being in the process of the local minorities' communicating, blending and struggling against the natural environment in the long course of history. It could be seen from this research that there were our preliminary research that there are quite abundant resources in Southeast of Guizhou in terms of prototypical ethnic cultures and genetic diversity of glutinous rice. A full reflection of the culture of Glutinous Rice could be seen in the local minority people's daily life, production, custom, religious belief, etc. These showed that the formation and great vitality of the genetic diversity of glutinous rice was not only determined by the diversity of local prototypical ethnic cultures but also to its own biotic condition and its adaptation to natural ecology. It was showed that prototypical ethnic cultures had positive impact on the conservation and utilization of Glutinous Rice diversity.