In this paper, we consider a novel two-dimensional(2D) geometry-based stochastic model(GBSM) for multiple-input multiple-output(MIMO) vehicle-to-vehicle(V2V) wideband fading channels. The proposed model employs the co...In this paper, we consider a novel two-dimensional(2D) geometry-based stochastic model(GBSM) for multiple-input multiple-output(MIMO) vehicle-to-vehicle(V2V) wideband fading channels. The proposed model employs the combination of a two-ring model and a multiple confocal ellipses model, where the signal is sum of the line-of-sight(Lo S) component, single-bounced(SB) rays, and double-bounced(DB) rays. Based on the reference model, we derive some expressions of channel statistical properties, including space-time correlation function(STCF), Doppler spectral power density(DPSD), envelope level crossing rate(LCR) and average fade duration(AFD). In addition, corresponding deterministic and stochastic simulation models are developed based on the reference model. Moreover, we compare the statistical properties of the reference model and the two simulation models in different scenarios and investigate the impact of different vehicular traffic densities(VTDs) on the channel statistical properties of the proposed model. Finally, the great agreement between simulation models and the reference model demonstrates not only the utility of simulation models, but also the correctness of theoretical derivations and simulations.展开更多
For complex chemical processes,process optimization is usually performed on causal models from first principle models.When the mechanism models cannot be obtained easily,restricted model built by process data is used ...For complex chemical processes,process optimization is usually performed on causal models from first principle models.When the mechanism models cannot be obtained easily,restricted model built by process data is used for dynamic process optimization.A new strategy is proposed for complex process optimization,in which latent variables are used as decision variables and statistics is used to describe constraints.As the constraint condition will be more complex by projecting the original variable to latent space,Hotelling T^2 statistics is introduced for constraint formulation in latent space.In this way,the constraint is simplified when the optimization is solved in low-dimensional space of latent variable.The validity of the methodology is illustrated in pH-level optimal control process and practical polypropylene grade transition process.展开更多
Purpose： To summarize the approach-avoidance achievement goal and performance in the sport psychology literature.Methods： A total of 17 published studies, two of which provided two samples, were located. Accepted me...Purpose： To summarize the approach-avoidance achievement goal and performance in the sport psychology literature.Methods： A total of 17 published studies, two of which provided two samples, were located. Accepted meta-analytic procedures were used with Hedges g as the effect size metric. From the 17 studies, 73 effect sizes were calculated.Results： Results based on a random effects model indicated that the performance goal contrast had the largest facilitative impact on performance followed by the mastery and performance approach goals. Both of the avoidance goals performance and mastery had small non-significant and detrimental effects on performance. The homogeneity statistics revealed significant heterogeneity for the approach and avoidance performance goals. Categorical moderator variables were examined for study sex composition（male, female, or mixed）, mean age of sample（〈18 years or 18 years）, study setting（lab or naturalistic）, and nature of performance variable（objective or subjective）.Conclusion： The performance goal contrast holds value for sport performance research. Contrary to approach-avoidance predictions, the mastery-approach goal and performance effect size was significant and of equal magnitude as the performance approach goal and performance effect size. Thus, future research should closely test the efficacy of both the mastery- and performance contrasts in impacting performance of sport tasks. Last, the significant effect sizes reported in this review are in stark contrast to contemporary meta-analytic findings in education.Differences in the approach-avoidance goals in sport and education relative to performance should be researched further.展开更多
This paper describes the stochastic model of the scattered electromagnetic field.Unlike common_used functional_determined models the proposed is characterised by amplitude/phase fluctuation of the received signal.This...This paper describes the stochastic model of the scattered electromagnetic field.Unlike common_used functional_determined models the proposed is characterised by amplitude/phase fluctuation of the received signal.This paper derives the statistical characteristic of the input signal and describes algorithm for its estimation in post_processing and real_time processing modes.Achieved characteristics allow the mapping and estimation of the surface models more accurate,moreover,such processing increase space resolution of synthetic aperture radar.展开更多
基金supported in part by the project from the ZTEthe National Natural Science Foundation of China under Grant 61622101 and Grant 61571020National Science and Technology Major Project under Grant 2018ZX03001031
文摘In this paper, we consider a novel two-dimensional(2D) geometry-based stochastic model(GBSM) for multiple-input multiple-output(MIMO) vehicle-to-vehicle(V2V) wideband fading channels. The proposed model employs the combination of a two-ring model and a multiple confocal ellipses model, where the signal is sum of the line-of-sight(Lo S) component, single-bounced(SB) rays, and double-bounced(DB) rays. Based on the reference model, we derive some expressions of channel statistical properties, including space-time correlation function(STCF), Doppler spectral power density(DPSD), envelope level crossing rate(LCR) and average fade duration(AFD). In addition, corresponding deterministic and stochastic simulation models are developed based on the reference model. Moreover, we compare the statistical properties of the reference model and the two simulation models in different scenarios and investigate the impact of different vehicular traffic densities(VTDs) on the channel statistical properties of the proposed model. Finally, the great agreement between simulation models and the reference model demonstrates not only the utility of simulation models, but also the correctness of theoretical derivations and simulations.
基金Supported by the National Natural Science Foundation of China(61174114)the Research Fund for the Doctoral Program of Higher Education in China(20120101130016)+1 种基金the Natural Science Foundation of Zhejiang Province(LQ15F030006)the Educational Commission Research Program of Zhejiang Province(Y201431412)
文摘For complex chemical processes,process optimization is usually performed on causal models from first principle models.When the mechanism models cannot be obtained easily,restricted model built by process data is used for dynamic process optimization.A new strategy is proposed for complex process optimization,in which latent variables are used as decision variables and statistics is used to describe constraints.As the constraint condition will be more complex by projecting the original variable to latent space,Hotelling T^2 statistics is introduced for constraint formulation in latent space.In this way,the constraint is simplified when the optimization is solved in low-dimensional space of latent variable.The validity of the methodology is illustrated in pH-level optimal control process and practical polypropylene grade transition process.
文摘Purpose： To summarize the approach-avoidance achievement goal and performance in the sport psychology literature.Methods： A total of 17 published studies, two of which provided two samples, were located. Accepted meta-analytic procedures were used with Hedges g as the effect size metric. From the 17 studies, 73 effect sizes were calculated.Results： Results based on a random effects model indicated that the performance goal contrast had the largest facilitative impact on performance followed by the mastery and performance approach goals. Both of the avoidance goals performance and mastery had small non-significant and detrimental effects on performance. The homogeneity statistics revealed significant heterogeneity for the approach and avoidance performance goals. Categorical moderator variables were examined for study sex composition（male, female, or mixed）, mean age of sample（〈18 years or 18 years）, study setting（lab or naturalistic）, and nature of performance variable（objective or subjective）.Conclusion： The performance goal contrast holds value for sport performance research. Contrary to approach-avoidance predictions, the mastery-approach goal and performance effect size was significant and of equal magnitude as the performance approach goal and performance effect size. Thus, future research should closely test the efficacy of both the mastery- and performance contrasts in impacting performance of sport tasks. Last, the significant effect sizes reported in this review are in stark contrast to contemporary meta-analytic findings in education.Differences in the approach-avoidance goals in sport and education relative to performance should be researched further.
文摘This paper describes the stochastic model of the scattered electromagnetic field.Unlike common_used functional_determined models the proposed is characterised by amplitude/phase fluctuation of the received signal.This paper derives the statistical characteristic of the input signal and describes algorithm for its estimation in post_processing and real_time processing modes.Achieved characteristics allow the mapping and estimation of the surface models more accurate,moreover,such processing increase space resolution of synthetic aperture radar.
