In this paper,we introduce the censored composite conditional quantile coefficient(cC-CQC)to rank the relative importance of each predictor in high-dimensional censored regression.The cCCQC takes advantage of all usef...In this paper,we introduce the censored composite conditional quantile coefficient(cC-CQC)to rank the relative importance of each predictor in high-dimensional censored regression.The cCCQC takes advantage of all useful information across quantiles and can detect nonlinear effects including interactions and heterogeneity,effectively.Furthermore,the proposed screening method based on cCCQC is robust to the existence of outliers and enjoys the sure screening property.Simulation results demonstrate that the proposed method performs competitively on survival datasets of high-dimensional predictors,particularly when the variables are highly correlated.展开更多
Crop water stress index(CWSI)is widely used for efficient irrigation management.Precise canopy temperature(T_(c))measurement is necessary to derive a reliable CWSI.The objective of this research was to investigate the...Crop water stress index(CWSI)is widely used for efficient irrigation management.Precise canopy temperature(T_(c))measurement is necessary to derive a reliable CWSI.The objective of this research was to investigate the influences of atmospheric conditions,settled height,view angle of infrared thermography,and investigating time of temperature measuring on the performance of the CWSI.Three irrigation treatments were used to create different soil water conditions during the 2020-2021 and 2021-2022 winter wheat-growing seasons.The CWSI was calculated using the CWSI-E(an empirical approach)and CWSI-T(a theoretical approach)based on the T_(c).Weather conditions were recorded continuously throughout the experimental period.The results showed that atmospheric conditions influenced the estimation of the CWSI;when the vapor pressure deficit(VPD)was>2000 Pa,the estimated CWSI was related to soil water conditions.The height of the installed infrared thermograph influenced the T_(c)values,and the differences among the T_(c)values measured at height of 3,5,and 10 m was smaller in the afternoon than in the morning.However,the lens of the thermometer facing south recorded a higher T_(c)than those facing east or north,especially at a low height,indicating that the direction of the thermometer had a significant influence on T_(c).There was a large variation in CWSI derived at different times of the day,and the midday measurements(12:00-15:00)were the most reliable for estimating CWSI.Negative linear relationships were found between the transpiration rate and CWSI-E(R^(2)of 0.3646-0.5725)and CWSI-T(R^(2)of 0.5407-0.7213).The relations between fraction of available soil water(FASW)with CWSI-T was higher than that with CWSI-E,indicating CWSI-T was more accurate for predicting crop water status.In addition,The R^(2)between CWSI-T and FASW at 14:00 was higher than that at other times,indicating that 14:00 was the optimal time for using the CWSI for crop water status monitoring.Relative higher yield of winter wheat was obtained with average seasonal values of CWSI-E and CWSI-T around 0.23 and 0.25-0.26,respectively.The CWSI-E values were more easily influenced by meteorological factors and the timing of the measurements,and using the theoretical approach to derive the CWSI was recommended for precise irrigation water management.展开更多
In order to provide important parameters for schedule designing, decision-making bases for transit operation management and references for passengers traveling by bus, bus transit travel time reliability is analyzed a...In order to provide important parameters for schedule designing, decision-making bases for transit operation management and references for passengers traveling by bus, bus transit travel time reliability is analyzed and evaluated based on automatic vehicle location （AVL） data. Based on the statistical analysis of the bus transit travel time, six indices including the coefficient of variance, the width of travel time distribution, the mean commercial speed, the congestion frequency, the planning time index and the buffer time index are proposed. Moreover, a framework for evaluating bus transit travel time reliability is constructed. Finally, a case study on a certain bus route in Suzhou is conducted. Results show that the proposed evaluation index system is simple and intuitive, and it can effectively reflect the efficiency and stability of bus operations. And a distinguishing feature of bus transit travel time reliability is the temporal pattern. It varies across different time periods.展开更多
类比推理是两类事物在许多方面有着相同的属性,进而推出在别的方面也有着相同属性的推理。其推理模式是:因为 M 具有属性 a、b、c、dN 具有属性 a、b、c所以 N 具有属性 d在小学数学教学中,培养学生的类比推理能力,不仅能使学生从中获...类比推理是两类事物在许多方面有着相同的属性,进而推出在别的方面也有着相同属性的推理。其推理模式是:因为 M 具有属性 a、b、c、dN 具有属性 a、b、c所以 N 具有属性 d在小学数学教学中,培养学生的类比推理能力,不仅能使学生从中获得知识,而且能使学生逐步形成自我获取知识的能力。这对他们以后独立学习、探索知识及其规律有着重要的作用。培养学生的类比推理能力,我以为——一、充分挖掘教材的类比因素数学知识是一个系统,这一系统中的各个知识点总会存在这样或那样的联系。如知识的顺延、从属、互逆、相似等等。就相似关系而言。展开更多
This paper introduces a novel digital transceiver for the cordless telephone zero （CT0） standard,which uses a digital modulation and demodulation technique to handle the signal instead of the traditional analog meth...This paper introduces a novel digital transceiver for the cordless telephone zero （CT0） standard,which uses a digital modulation and demodulation technique to handle the signal instead of the traditional analog meth-od. In the transmitter,a fractional-N phase locked loop （PLL） is utilized to realize the continuous phase frequency shift key （CPFSK） modulation,and a 2 Ts raised cosine （2RC） shaping technique is used to reduce the occupied bandwidth. In the receiver,a novel digital method is proposed to demodulate the 2RC CPFSK signal. This chip is fabricated using an SMIC 0.35μm mixed signal CMOS process with a die size of 2mm × 2mm. With an external low noise amplifier （LNA）,the sensitivity of the chip is better than -103dBm.展开更多
In order to reduce amount of data storage and improve processing capacity of the system, this paper proposes a new classification method of data source by combining phase synchronization model in network clusteri...In order to reduce amount of data storage and improve processing capacity of the system, this paper proposes a new classification method of data source by combining phase synchronization model in network clustering with cloud model. Firstly, taking data source as a complex network, after the topography of network is obtained, the cloud model of each node data is determined by fuzzy analytic hierarchy process （AHP）. Secondly, by calculating expectation, entropy and hyper entropy of the cloud model, comprehensive coupling strength is got and then it is regarded as the edge weight of topography. Finally, distribution curve is obtained by iterating the phase of each node by means of phase synchronization model. Thus classification of data source is completed. This method can not only provide convenience for storage, cleaning and compression of data, but also improve the efficiency of data analysis.展开更多
Xinli district of Sanshandao Gold Mine is the first subsea metal mine in China.To achieve 6 kt/d production capacity under the premise of safe mining,high-intensity mining might destroy the in-situ stress filed and th...Xinli district of Sanshandao Gold Mine is the first subsea metal mine in China.To achieve 6 kt/d production capacity under the premise of safe mining,high-intensity mining might destroy the in-situ stress filed and the stability of rockmass.According to sampling and testing of ore-rock and backfill and in-situ stress field measurement,safety factor method calculation model based on stress-strain strength reduction at arbitrary points and Mohr-Coulomb yield criterion was established and limit displacement subsidence values under the safety factor of different limit stoping steps were calculated.The results from three years in-situ mining and strata movement monitoring using multi-point displacements meter showed that the lower settlement frame stope hierarchical level filling mining method,mining sequence are reasonable and rockmass stability evaluation using safety factor method,in-situ real-time monitoring can provide the technical foundation for the safety of seabed mining.展开更多
The reaction of C3H8＋O（^3p）→C3HT＋OH is investigated using ab initio calculation and dynamical methods. Electronic structure calculations for all stationary points are obtained using a dual-level strategy. The geo...The reaction of C3H8＋O（^3p）→C3HT＋OH is investigated using ab initio calculation and dynamical methods. Electronic structure calculations for all stationary points are obtained using a dual-level strategy. The geometry optimization is performed using the unrestricted second-order Moller-Plesset perturbation method and the single-point energy is computed us- ing the coupled-cluster singles and doubles augmented by a perturbative treatment of triple excitations method. Results indicate that the main reaction channel is C3Hs＋O（^3p）→i- C3HT＋OH. Based upon the ab initio data, thermal rate constants are calculated using the variational transition state theory method with the temperature ranging from 298 K to 1000 K. These calculated rate constants are in better agreement with experiments than those reported in previous theoretical studies, and the branching ratios of the reaction are also calculated in the present work. Furthermore, the isotope effects of the title reaction are calculated and discussed. The present work reveals the reaction mechanism of hydrogenabstraction from propane involving reaction channel competitions is helpful for the understanding of propane combustion.展开更多
Background Primary percutaneous intervention （PPCI） is the treatment of choice for ST elevation myocardial infarction （STEMI） but robust evidence in the very elderly is lacking. We compared PPCI outcomes between d...Background Primary percutaneous intervention （PPCI） is the treatment of choice for ST elevation myocardial infarction （STEMI） but robust evidence in the very elderly is lacking. We compared PPCI outcomes between different age quartiles （quartile I 〈 60 years, quartile 2 〉 60 to 〈 70 years, quartile 3 〉 70 to 〈 80 years, quartile 4 〉 80 years）. Methods Retrospective observational analysis of our Morriston Tertiary Cardiac Center （Abertawe Bro Morgannwg University Health Board） patients from 2005 to 2010 with STEMI who underwent PPCI. Resnlts Of 434 patients, 57 （13%） were in quartile 4 （〉 80 years）. In older age quartiles, patients were less likely to receive a drug eluting stent （DES, P = 0.001） or glycoprotein IlbAIIa inhibitor （GPI, P 〈 0.0001）. Increase in age was associated with reduced time to survival （13-coefficient： -0.192, t： -3,70, 95%CI： --4.91 to -1.50, P 〈 0.0001） as was the presence of cardiogenic shock 03-coefficient： -0.194, t = 3.77, 95%CI： -5.26 to -1.65, P 〈 0.0001）. Use of GPI was associated with increased time to survival （p-coefficient： 0.138, t = 2.82, 95%CI： 1.58-8.58, P = 0.005） but older age quartiles were less likely to receive GPI （P 〈 0.0001）. In-hospital mortality （1.8% quartile 1, 3.6% quartile 2, 10.9% quartile 3 and 12.3% quartile 4, P = 0.002） and 1-year mortality （5.4% quartile 1, 5.5% quartile 2, 16.8% quartile 3 and 24.6% quartile 4, P 〈 0.0001, respectively） was significantly higher in older age quartiles. Conclusions Increased short term and intermediate term mortality is seen in the very elderly after PPCI. Age and cardiogenic shock were prognostic factors. Intervention should not be based on age alone and awareness regarding prognostic factors can help improve management.展开更多
基金Outstanding Youth Foundation of Hunan Provincial Department of Education(Grant No.22B0911)。
文摘In this paper,we introduce the censored composite conditional quantile coefficient(cC-CQC)to rank the relative importance of each predictor in high-dimensional censored regression.The cCCQC takes advantage of all useful information across quantiles and can detect nonlinear effects including interactions and heterogeneity,effectively.Furthermore,the proposed screening method based on cCCQC is robust to the existence of outliers and enjoys the sure screening property.Simulation results demonstrate that the proposed method performs competitively on survival datasets of high-dimensional predictors,particularly when the variables are highly correlated.
基金supported by the Project of State Grid Hebei Electric Power Co.,Ltd.(SGHEYX00SCJS2100077).
文摘Crop water stress index(CWSI)is widely used for efficient irrigation management.Precise canopy temperature(T_(c))measurement is necessary to derive a reliable CWSI.The objective of this research was to investigate the influences of atmospheric conditions,settled height,view angle of infrared thermography,and investigating time of temperature measuring on the performance of the CWSI.Three irrigation treatments were used to create different soil water conditions during the 2020-2021 and 2021-2022 winter wheat-growing seasons.The CWSI was calculated using the CWSI-E(an empirical approach)and CWSI-T(a theoretical approach)based on the T_(c).Weather conditions were recorded continuously throughout the experimental period.The results showed that atmospheric conditions influenced the estimation of the CWSI;when the vapor pressure deficit(VPD)was>2000 Pa,the estimated CWSI was related to soil water conditions.The height of the installed infrared thermograph influenced the T_(c)values,and the differences among the T_(c)values measured at height of 3,5,and 10 m was smaller in the afternoon than in the morning.However,the lens of the thermometer facing south recorded a higher T_(c)than those facing east or north,especially at a low height,indicating that the direction of the thermometer had a significant influence on T_(c).There was a large variation in CWSI derived at different times of the day,and the midday measurements(12:00-15:00)were the most reliable for estimating CWSI.Negative linear relationships were found between the transpiration rate and CWSI-E(R^(2)of 0.3646-0.5725)and CWSI-T(R^(2)of 0.5407-0.7213).The relations between fraction of available soil water(FASW)with CWSI-T was higher than that with CWSI-E,indicating CWSI-T was more accurate for predicting crop water status.In addition,The R^(2)between CWSI-T and FASW at 14:00 was higher than that at other times,indicating that 14:00 was the optimal time for using the CWSI for crop water status monitoring.Relative higher yield of winter wheat was obtained with average seasonal values of CWSI-E and CWSI-T around 0.23 and 0.25-0.26,respectively.The CWSI-E values were more easily influenced by meteorological factors and the timing of the measurements,and using the theoretical approach to derive the CWSI was recommended for precise irrigation water management.
基金The Soft Science Research Project of Ministry of Housing and Urban-Rural Development of China (No. 2008-k5-14)
文摘In order to provide important parameters for schedule designing, decision-making bases for transit operation management and references for passengers traveling by bus, bus transit travel time reliability is analyzed and evaluated based on automatic vehicle location （AVL） data. Based on the statistical analysis of the bus transit travel time, six indices including the coefficient of variance, the width of travel time distribution, the mean commercial speed, the congestion frequency, the planning time index and the buffer time index are proposed. Moreover, a framework for evaluating bus transit travel time reliability is constructed. Finally, a case study on a certain bus route in Suzhou is conducted. Results show that the proposed evaluation index system is simple and intuitive, and it can effectively reflect the efficiency and stability of bus operations. And a distinguishing feature of bus transit travel time reliability is the temporal pattern. It varies across different time periods.
文摘类比推理是两类事物在许多方面有着相同的属性,进而推出在别的方面也有着相同属性的推理。其推理模式是:因为 M 具有属性 a、b、c、dN 具有属性 a、b、c所以 N 具有属性 d在小学数学教学中,培养学生的类比推理能力,不仅能使学生从中获得知识,而且能使学生逐步形成自我获取知识的能力。这对他们以后独立学习、探索知识及其规律有着重要的作用。培养学生的类比推理能力,我以为——一、充分挖掘教材的类比因素数学知识是一个系统,这一系统中的各个知识点总会存在这样或那样的联系。如知识的顺延、从属、互逆、相似等等。就相似关系而言。
文摘This paper introduces a novel digital transceiver for the cordless telephone zero （CT0） standard,which uses a digital modulation and demodulation technique to handle the signal instead of the traditional analog meth-od. In the transmitter,a fractional-N phase locked loop （PLL） is utilized to realize the continuous phase frequency shift key （CPFSK） modulation,and a 2 Ts raised cosine （2RC） shaping technique is used to reduce the occupied bandwidth. In the receiver,a novel digital method is proposed to demodulate the 2RC CPFSK signal. This chip is fabricated using an SMIC 0.35μm mixed signal CMOS process with a die size of 2mm × 2mm. With an external low noise amplifier （LNA）,the sensitivity of the chip is better than -103dBm.
基金National Natural Science Foundation of China(No.61171057,No.61503345)Science Foundation for North University of China(No.110246)+1 种基金Specialized Research Fund for Doctoral Program of Higher Education of China(No.20121420110004)International Office of Shanxi Province Education Department of China,and Basic Research Project in Shanxi Province(Young Foundation)
文摘In order to reduce amount of data storage and improve processing capacity of the system, this paper proposes a new classification method of data source by combining phase synchronization model in network clustering with cloud model. Firstly, taking data source as a complex network, after the topography of network is obtained, the cloud model of each node data is determined by fuzzy analytic hierarchy process （AHP）. Secondly, by calculating expectation, entropy and hyper entropy of the cloud model, comprehensive coupling strength is got and then it is regarded as the edge weight of topography. Finally, distribution curve is obtained by iterating the phase of each node by means of phase synchronization model. Thus classification of data source is completed. This method can not only provide convenience for storage, cleaning and compression of data, but also improve the efficiency of data analysis.
基金Project(10872218) supported by the National Natural Science Foundation of ChinaProject(2010CB732004) supported by the National Key Basic Research Program of China+1 种基金Project(20090461022) supported by the National Postdoctoral Foundation of ChinaProject (11MX21) supported by the Students' Innovation Project Aubsidize Award of Arcelor Mittal
文摘Xinli district of Sanshandao Gold Mine is the first subsea metal mine in China.To achieve 6 kt/d production capacity under the premise of safe mining,high-intensity mining might destroy the in-situ stress filed and the stability of rockmass.According to sampling and testing of ore-rock and backfill and in-situ stress field measurement,safety factor method calculation model based on stress-strain strength reduction at arbitrary points and Mohr-Coulomb yield criterion was established and limit displacement subsidence values under the safety factor of different limit stoping steps were calculated.The results from three years in-situ mining and strata movement monitoring using multi-point displacements meter showed that the lower settlement frame stope hierarchical level filling mining method,mining sequence are reasonable and rockmass stability evaluation using safety factor method,in-situ real-time monitoring can provide the technical foundation for the safety of seabed mining.
文摘The reaction of C3H8＋O（^3p）→C3HT＋OH is investigated using ab initio calculation and dynamical methods. Electronic structure calculations for all stationary points are obtained using a dual-level strategy. The geometry optimization is performed using the unrestricted second-order Moller-Plesset perturbation method and the single-point energy is computed us- ing the coupled-cluster singles and doubles augmented by a perturbative treatment of triple excitations method. Results indicate that the main reaction channel is C3Hs＋O（^3p）→i- C3HT＋OH. Based upon the ab initio data, thermal rate constants are calculated using the variational transition state theory method with the temperature ranging from 298 K to 1000 K. These calculated rate constants are in better agreement with experiments than those reported in previous theoretical studies, and the branching ratios of the reaction are also calculated in the present work. Furthermore, the isotope effects of the title reaction are calculated and discussed. The present work reveals the reaction mechanism of hydrogenabstraction from propane involving reaction channel competitions is helpful for the understanding of propane combustion.
文摘Background Primary percutaneous intervention （PPCI） is the treatment of choice for ST elevation myocardial infarction （STEMI） but robust evidence in the very elderly is lacking. We compared PPCI outcomes between different age quartiles （quartile I 〈 60 years, quartile 2 〉 60 to 〈 70 years, quartile 3 〉 70 to 〈 80 years, quartile 4 〉 80 years）. Methods Retrospective observational analysis of our Morriston Tertiary Cardiac Center （Abertawe Bro Morgannwg University Health Board） patients from 2005 to 2010 with STEMI who underwent PPCI. Resnlts Of 434 patients, 57 （13%） were in quartile 4 （〉 80 years）. In older age quartiles, patients were less likely to receive a drug eluting stent （DES, P = 0.001） or glycoprotein IlbAIIa inhibitor （GPI, P 〈 0.0001）. Increase in age was associated with reduced time to survival （13-coefficient： -0.192, t： -3,70, 95%CI： --4.91 to -1.50, P 〈 0.0001） as was the presence of cardiogenic shock 03-coefficient： -0.194, t = 3.77, 95%CI： -5.26 to -1.65, P 〈 0.0001）. Use of GPI was associated with increased time to survival （p-coefficient： 0.138, t = 2.82, 95%CI： 1.58-8.58, P = 0.005） but older age quartiles were less likely to receive GPI （P 〈 0.0001）. In-hospital mortality （1.8% quartile 1, 3.6% quartile 2, 10.9% quartile 3 and 12.3% quartile 4, P = 0.002） and 1-year mortality （5.4% quartile 1, 5.5% quartile 2, 16.8% quartile 3 and 24.6% quartile 4, P 〈 0.0001, respectively） was significantly higher in older age quartiles. Conclusions Increased short term and intermediate term mortality is seen in the very elderly after PPCI. Age and cardiogenic shock were prognostic factors. Intervention should not be based on age alone and awareness regarding prognostic factors can help improve management.
