In this paper, by defining new state vectors and developing new transfer matrices of various elements mov- ing in space, the discrete time transfer matrix method of multi-rigid-flexible-body system is expanded to stud...In this paper, by defining new state vectors and developing new transfer matrices of various elements mov- ing in space, the discrete time transfer matrix method of multi-rigid-flexible-body system is expanded to study the dynamics of multibody system with flexible beams moving in space. Formulations and numerical example of a rigid- flexible-body three pendulums system moving in space are given to validate the method. Using the new method to study the dynamics of multi-rigid-flexible-body system mov- ing in space, the global dynamics equations of system are not needed, the orders of involved matrices of the system are very low and the computational speed is high, irrespec- tive of the size of the system. The new method is simple, straightforward, practical, and provides a powerful tool for multi-rigid-flexible-body system dynamics.展开更多
In the big data environment, enterprises must constantly assimilate big dataknowledge and private knowledge by multiple knowledge transfers to maintain theircompetitive advantage. The optimal time of knowledge transfe...In the big data environment, enterprises must constantly assimilate big dataknowledge and private knowledge by multiple knowledge transfers to maintain theircompetitive advantage. The optimal time of knowledge transfer is one of the mostimportant aspects to improve knowledge transfer efficiency. Based on the analysis of thecomplex characteristics of knowledge transfer in the big data environment, multipleknowledge transfers can be divided into two categories. One is the simultaneous transferof various types of knowledge, and the other one is multiple knowledge transfers atdifferent time points. Taking into consideration the influential factors, such as theknowledge type, knowledge structure, knowledge absorptive capacity, knowledge updaterate, discount rate, market share, profit contributions of each type of knowledge, transfercosts, product life cycle and so on, time optimization models of multiple knowledgetransfers in the big data environment are presented by maximizing the total discountedexpected profits (DEPs) of an enterprise. Some simulation experiments have beenperformed to verify the validity of the models, and the models can help enterprisesdetermine the optimal time of multiple knowledge transfer in the big data environment.展开更多
A system of jointly transferring time signals with a rate of 1 pulse per second (PPS) and frequency signals of 10 MHz via a dense wavelength division multiplex-based (DWDM) fiber is demonstrated in this paper. The...A system of jointly transferring time signals with a rate of 1 pulse per second (PPS) and frequency signals of 10 MHz via a dense wavelength division multiplex-based (DWDM) fiber is demonstrated in this paper. The noises of the fiber links are suppressed and compensated for by a controlled fiber delay line. A method of calibrating and characterizing time is described. The 1PPS is synchronized by feed-forward calibrating the fiber delays precisely. The system is experimen- tally examined via a 110 km spooled fiber in laboratory. The frequency stabilities of the user end with compensation are 1.8x 10-14 at 1 s and 2.0x 10-17 at 104 s average time. The calculated uncertainty of time synchronization is 13.1 ps, whereas the direct measurement of the uncertainty is 12 ps. Next, the frequency and 1PPS are transferred via a metropoli- tan area optical fiber network from one central site to two remote sites with distances of 14 km and 110 km. The frequency stabilities of 14 km link reach 3.0x 10-14 averaged in 1 s and 1.4x 10-17 in 104 s respectively; and the stabilities of 110 km link are 8.3 x 10-14 and 1.7 x 10-17, respectively. The accuracies of synchronization are estimated to be 12.3 ps for the 14 km link and 13.1 ps for the 110 km link, respectively.展开更多
Efficient real time data exchange over the Internet plays a crucial role in the successful application of web-based systems. In this paper, a data transfer mechanism over the Internet is proposed for real time web bas...Efficient real time data exchange over the Internet plays a crucial role in the successful application of web-based systems. In this paper, a data transfer mechanism over the Internet is proposed for real time web based applications. The mechanism incorporates the eXtensible Markup Language (XML) and Hierarchical Data Format (HDF) to provide a flexible and efficient data format. Heterogeneous transfer data is classified into light and heavy data, which are stored using XML and HDF respectively; the HDF data format is then mapped to Java Document Object Model (JDOM) objects in XML in the Java environment. These JDOM data objects are sent across computer networks with the support of the Java Remote Method Invocation (RMI) data transfer infrastructure. Client's defined data priority levels are implemented in RMI, which guides a server to transfer data objects at different priorities. A remote monitoring system for an industrial reactor process simulator is used as a case study to illustrate the proposed data transfer mechanism.展开更多
Background Key performance indices such as door-to-balloon times have long been recognized as quality metrics in reducing time to care for patients with acute coronary syndromes(ACS). In the situation where patients d...Background Key performance indices such as door-to-balloon times have long been recognized as quality metrics in reducing time to care for patients with acute coronary syndromes(ACS). In the situation where patients do not present to a facility capable of 24/7 percutaneous coronary interventions(PCI) delays in time to therapy can exceed the recommendation of 90 min or less. This study aimed to evaluate the impact of transfers on performance indices for patients diagnosed with ST-segment elevation myocardial infarction(STEMI). Methods Over a seven month collection period, all patients presenting with symptoms suggestive of ACS and admitted for PCI were studied. Patients were divided into dichotomous groups of direct presentations or transfers from a secondary non-PCI capable hospital with key times recorded, including symptom-onset, first hospital and PCI-capable hospital arrival and balloon inflation times to evaluate time of treatment for STEMI patients. Results Of the 87 patients diagnosed with STEMI, transferred patients experienced statistically significant delays in symptom-onset to the PCI-capable hospital(PCI-H) arrival(215 vs. 95 min, P < 0.001), symptom-onset to balloon inflation(225 vs. 160 min, P = 0.009) and first hospital arrival to balloon inflation times(106 vs. 56 min, P < 0.001). Only 28%(n = 9) of transferred patients underwent balloon inflation within 90 min from first hospital arrival, while 60%(n = 19) did within 120 min, although all received balloon inflation within 90 min from arrival at the PCI-H. After controlling for confounding factors of socio-economic status, presentation date/time and diagnostic category, transferred patients experienced an average 162% longer delays from symptom-onset to PCI-H door arrival, and 98% longer delays in symptom-onset to balloon inflation;compared to patients who present directly to the PCI-H. No statistically significant differences were noted between transferred and direct patients when measured from PCI-H door-to-balloon times. Conclusions This study shows that transferred patients experience a greater overall system delay, compared to patients who present directly for PCI, significantly increasing their time to treatment and therefore infarct times. Despite the majority of transfers experiencing pre-hospital activation, their treatment hospital arrival to balloon times are no less than direct presenters after controlling for confounding factors, further compounding the overall delay to therapy.展开更多
三个功能的模特儿,多项式,光谱分析,和修改 AR 当模特儿,基于从双向卫星时间和频率转移导出的数据顺序在恰当、预言的钟偏差被学习并且比较。柔韧的当量被使用,它控制无关的观察的重要影响。一些结论证明柔韧的评价的预言精确比 LS...三个功能的模特儿,多项式,光谱分析,和修改 AR 当模特儿,基于从双向卫星时间和频率转移导出的数据顺序在恰当、预言的钟偏差被学习并且比较。柔韧的当量被使用,它控制无关的观察的重要影响。一些结论证明柔韧的评价的预言精确比 LS 的好。从弄平的观察计算的预言精确比从采样观察计算了高。作为在钟偏差顺序的明显的时期变化的一个计数,多项式模型的预言的价值是难以置信的。光谱分析模型的预言精确是很低的,但是主要时期能是坚定的。6 小时的推测间隔的预言 RMS 是 1 ns 左右,当修改 AR 模型被使用时。展开更多
High-precision time transfer plays an important role in the areas of fundamental research and applications. Accompanying w ith the remarkable improvements in the ability of generating and measuring high-accuracy time-...High-precision time transfer plays an important role in the areas of fundamental research and applications. Accompanying w ith the remarkable improvements in the ability of generating and measuring high-accuracy time-frequency signal,seeking for new time-transfer techniques betw een distant clocks w ith much further improved accuracy attracts attentions w orld-w idely. The time-transfer technique based on optical pulses has the highest precision presently,and the further improvement in the accuracy is heavily dependent on the time-domain properties of the pulse as w ell as the sensitivity of the applied measurement on the exchanged pulse. The application of optical frequency comb in time transfer for a precision up to femtosecond level are currently the focus of much interest,and has recently achieved many breakthroughs. Further investigations show that,utilizing quantum techniques,i.e. quantum measurement technique and quantum optical pulse source,can lead to a new limit on the measured timing information. Furthermore,it can be immune from atmospheric parameters,such as pressure,temperature,humidity and so on.Such quantum improvements on time-transfer have a bright prospect in the future applications requiring extremely high-accuracy timing and ranging. The potential achievements w ill form a technical basis for the future realization of sub-femtosecond time transfer system.展开更多
Two methods for smoothing pseudorange observable by Carrier and Doppler are discussed. Then the procedure based on the RINEX observation files is tested using the Ashtech Z-XII3T geodetic receivers driven by a stable ...Two methods for smoothing pseudorange observable by Carrier and Doppler are discussed. Then the procedure based on the RINEX observation files is tested using the Ashtech Z-XII3T geodetic receivers driven by a stable external frequency at UNSO. This paper proposes to adapt this procedure for the links between geodetic receivers, in order to take advantage of the P codes available on L 1 and L 2. This new procedure uses the 30-second RINEX observations files, the standard of the International GPS Service (IGS), and processes the ionosphere-free combination of the codes P 1 and P 2; the satellite positions are deduced from the IGS rapid orbits, available after two days.展开更多
A self-adaptive precise algorithm in the time domain was employed to solve 2-D nonlinear coupled heat and moisture transfer problems. By expanding variables at a discretized time interval, the variations of variables ...A self-adaptive precise algorithm in the time domain was employed to solve 2-D nonlinear coupled heat and moisture transfer problems. By expanding variables at a discretized time interval, the variations of variables can be described more precisely,and a nonlinear coupled initial and boundary value problem was converted into a series of recurrent linear boundary value problems which are solved by FE technique. In the computation, no additional assumption and the nonlinear iteration are required, and a criterion for self-adaptive computation is proposed to maintain sufficient computing accuracy for the change sizes of time steps. In the numerical comparison, the variations of material properties with temperature, moisture content, and both temperature and moisture content are taken into account, respectively. Satisfactory results have been obtained, indicating that the proposed approach is capable of dealing with complex nonlinear problems.展开更多
Considering the increasing use of information technology with established standards, such as TCP/IP and XML in modern industrial automation, we present a high cost performance solution with FPGA (field programmable ga...Considering the increasing use of information technology with established standards, such as TCP/IP and XML in modern industrial automation, we present a high cost performance solution with FPGA (field programmable gate array) imple-mentation of a novel reliable real-time data transfer system based on EPA (Ethernet for plant automation) protocol and IEEE 1588 standard. This combination can provide more predictable and real-time communication between automation equipments and precise synchronization between devices. The designed EPA system has been verified on Xilinx Spartan3 XC3S1500 and it consumed 75% of the total slices. The experimental results show that the novel industrial control system achieves high synchro-nization precision and provides a 1.59-μs standard deviation between the master device and the slave ones. Such a real-time data transfer system is an excellent candidate for automation equipments which require precise synchronization based on Ethernet at a comparatively low price.展开更多
The influence of quench transfer time on the microstructure and mechanical properties of 7055 aluminum alloy with and without zirconium was investigated by tensile properties test,optical microscopy,scanning electron ...The influence of quench transfer time on the microstructure and mechanical properties of 7055 aluminum alloy with and without zirconium was investigated by tensile properties test,optical microscopy,scanning electron microscopy and transmission electron microscopy.For the Zr-free alloy,the strength increases to the highest value at 20 s with transfer time,and then decreases slightly.The elongation decreases slowly with transfer time within 20 s,and more rapidly after 20 s.For the Zr-containing alloy,prolonging transfer time within 20 s results in slight decrease in the strength and elongation,and rapid drop of which is observed after 20 s.For the Zr-free alloy,prolonging transfer time can increase the percentage of intergranular fracture,which is mainly caused by wide grain boundary precipitate free zone.The failure mode of the Zr-containing alloy is modified from the predominant transgranular void growth and intergranular fracture to transgranular shear and intergranular fracture with increase in the transfer time,which is attributed to the wider grain boundary precipitate free zone and coarse equilibrium η phases in the matrix.展开更多
Objective:To explore the effect of different fertilization time after human chorionic gonadotropin(HCG)injection on the outcome of fertilization in vitro fertilization-embryo transfer(IVF-ET).Methods:One thousand one ...Objective:To explore the effect of different fertilization time after human chorionic gonadotropin(HCG)injection on the outcome of fertilization in vitro fertilization-embryo transfer(IVF-ET).Methods:One thousand one hundred and forty IVF-ET cycles from January 2016 to August 2018 were analyzed retrospectively.According to the different fertilization time after injection of HCG divided into four groups:Group A(38.0 h~39.0 h),Group B(39.1 h~40.0 h),Group C(40.1 h~41.0 h),and Group D(41.1 h~42.0 h).The normal fertilization rate,the normal cleavage rate,the embryo utilization rate,the high-quality embryo rate,the clinical pregnancy rate,the implantation rate,and the spontaneous abortion rate were analyzed among the groups.Then we investigated the effect of different promotion methods on the outcome of fertilization during the optimal fertilization time.Results:There was no significant difference in 2PN cleavage rate,available embryo rate,clinical pregnancy rate,implantation rate and abortion rate among the four groups(P>0.05).The high-quality embryo rate in Group D(44.6%)was the highest,and was significantly different among the four groups(P<0.05).The normal fertilization rate in Group D(71.6%)was the highest,and was significantly different among the four groups(P<0.05).The normal fertilization rate(78.1%)of antagonist group was significantly higher than other groups(P<0.05).Conclusion:The different fertilization time after HCG injection have effects on high-quality embryo rate and normal fertilization rate of patients in IVF-ET.The appropriate fertilization time of patients in IVF-ET was 41 h~42 h after HCG injection in our reproductive center,improved the clinical pregnancy rate and reduced the early abortion rate.The GnRH-ant protocol is superior to other protocol in IVF-ET.展开更多
History proves that some countries and regions benefited from international industry transfer, because of international industrial transfer can stimulate their economic growth.Thanks to the manufacturing transfer impl...History proves that some countries and regions benefited from international industry transfer, because of international industrial transfer can stimulate their economic growth.Thanks to the manufacturing transfer implemented by EU, USA, Japan and some Asian developed countries in 1980s, China’s economic situation has boomed over 30 years. Textile industry as a traditional industry in China has its own competitive advantage. It can be confirmed that textile industry will play an important role during the fourth Industry transfer period. So, who will be the winner this time?展开更多
The rapid advancement of Internet of Things(IoT)technology has brought convenience to people’s lives;however further development of IoT faces serious challenges,such as limited energy and shortage of network spectrum...The rapid advancement of Internet of Things(IoT)technology has brought convenience to people’s lives;however further development of IoT faces serious challenges,such as limited energy and shortage of network spectrum resources.To address the above challenges,this study proposes a simultaneous wireless information and power transfer IoT adaptive time slot resource allocation(SIATS)algorithm.First,an adaptive time slot consisting of periods for sensing,information transmission,and energy harvesting is designed to ensure that the minimum energy harvesting requirement ismet while the maximumuplink and downlink throughputs are obtained.Second,the optimal transmit power and channel assignment of the system are obtained using the Lagrangian dual and gradient descent methods,and the optimal time slot assignment is determined for each IoT device such that the sum of the throughput of all devices is maximized.Simulation results show that the SIATS algorithm performs satisfactorily and provides an increase in the throughput by up to 14.4%compared with that of the fixed time slot allocation(FTS)algorithm.In the case of a large noise variance,the SIATS algorithm has good noise immunity,and the total throughput of the IoT devices obtained using the SIATS algorithm can be improved by up to 34.7%compared with that obtained using the FTS algorithm.展开更多
Time-dependent density functional theory(TDDFT) method is used to investigate the details of the excited state intramolecular proton transfer(ESIPT) process and the mechanism for temperature effect on the Enol*/K...Time-dependent density functional theory(TDDFT) method is used to investigate the details of the excited state intramolecular proton transfer(ESIPT) process and the mechanism for temperature effect on the Enol*/Keto*emission ratio for the Me2N-substited flavonoid(MNF) compound. The geometric structures of the S0 and S1 states are denoted as the Enol, Enol*, and Keto*. In addition, the absorption and fluorescence peaks are also calculated. It is noted that the calculated large Stokes shift is in good agreement with the experimental result. Furthermore, our results confirm that the ESIPT process happens upon photoexcitation, which is distinctly monitored by the formation and disappearance of the characteristic peaks of infrared(IR) spectra involved in the proton transfer and in the potential energy curves. Besides, the calculations of highest occupied molecular orbital(HOMO) and lowest unoccupied molecular orbital(LUMO) reveal that the electronegativity change of proton acceptor due to the intramolecular charge redistribution in the S1 state induces the ESIPT. Moreover, the thermodynamic calculation for the MNF shows that the Enol*/Keto*emission ratio decreasing with temperature increasing arises from the barrier lowering of ESIPT.展开更多
In forecasting real time environmental factors,large data is needed to analyse the pattern behind the data values.Air pollution is a major threat towards developing countries and it is proliferating every year.Many me...In forecasting real time environmental factors,large data is needed to analyse the pattern behind the data values.Air pollution is a major threat towards developing countries and it is proliferating every year.Many methods in time ser-ies prediction and deep learning models to estimate the severity of air pollution.Each independent variable contributing towards pollution is necessary to analyse the trend behind the air pollution in that particular locality.This approach selects multivariate time series and coalesce a real time updatable autoregressive model to forecast Particulate matter(PM)PM2.5.To perform experimental analysis the data from the Central Pollution Control Board(CPCB)is used.Prediction is car-ried out for Chennai with seven locations and estimated PM’s using the weighted ensemble method.Proposed method for air pollution prediction unveiled effective and moored performance in long term prediction.Dynamic budge with high weighted k-models are used simultaneously and devising an ensemble helps to achieve stable forecasting.Computational time of ensemble decreases with paral-lel processing in each sub model.Weighted ensemble model shows high perfor-mance in long term prediction when compared to the traditional time series models like Vector Auto-Regression(VAR),Autoregressive Integrated with Mov-ing Average(ARIMA),Autoregressive Moving Average with Extended terms(ARMEX).Evaluation metrics like Root Mean Square Error(RMSE),Mean Absolute Error(MAE)and the time to achieve the time series are compared.展开更多
The forecasting research literature has developed greatly in recent years as a result of advances in information technology. Financial time-series tasks have made substantial use of machine learning and deep neural ne...The forecasting research literature has developed greatly in recent years as a result of advances in information technology. Financial time-series tasks have made substantial use of machine learning and deep neural networks, but building a prediction model from scratch takes time and computational resources. Transfer learning is growing popular in tackling these constraints of training time and computational resources in several disciplines. This study proposes a hybrid base model for the financial time series prediction employing the recurrent neural network (RNN) and long-short term memory (LSTM) called RNN-LSTM. We used random search to fine-tune the hyperparameters and compared our proposed model to the RNN and LSTM base models and evaluate using the RMSE, MAE, and MAPE metrics. When forecasting Forex currency pairs GBP/USD, USD/ZAR, and AUD/NZD our proposed base model for transfer learning outperforms RNN and LSTM base model with root mean squared errors of 0.007656, 0.165250, and 0.001730 respectively.展开更多
基金supported by the Natural Science Foundation of China Government (10902051)the Natural Science Foundation of Jiangsu Province (BK2008046)the German Science Foundation
文摘In this paper, by defining new state vectors and developing new transfer matrices of various elements mov- ing in space, the discrete time transfer matrix method of multi-rigid-flexible-body system is expanded to study the dynamics of multibody system with flexible beams moving in space. Formulations and numerical example of a rigid- flexible-body three pendulums system moving in space are given to validate the method. Using the new method to study the dynamics of multi-rigid-flexible-body system mov- ing in space, the global dynamics equations of system are not needed, the orders of involved matrices of the system are very low and the computational speed is high, irrespec- tive of the size of the system. The new method is simple, straightforward, practical, and provides a powerful tool for multi-rigid-flexible-body system dynamics.
基金supported by the National Natural Science Foundation ofChina (Grant No. 71704016,71331008, 71402010)the Natural Science Foundation of HunanProvince (Grant No. 2017JJ2267)+1 种基金the Educational Economy and Financial Research Base ofHunan Province (Grant No. 13JCJA2)the Project of China Scholarship Council forOverseas Studies (201508430121, 201208430233).
文摘In the big data environment, enterprises must constantly assimilate big dataknowledge and private knowledge by multiple knowledge transfers to maintain theircompetitive advantage. The optimal time of knowledge transfer is one of the mostimportant aspects to improve knowledge transfer efficiency. Based on the analysis of thecomplex characteristics of knowledge transfer in the big data environment, multipleknowledge transfers can be divided into two categories. One is the simultaneous transferof various types of knowledge, and the other one is multiple knowledge transfers atdifferent time points. Taking into consideration the influential factors, such as theknowledge type, knowledge structure, knowledge absorptive capacity, knowledge updaterate, discount rate, market share, profit contributions of each type of knowledge, transfercosts, product life cycle and so on, time optimization models of multiple knowledgetransfers in the big data environment are presented by maximizing the total discountedexpected profits (DEPs) of an enterprise. Some simulation experiments have beenperformed to verify the validity of the models, and the models can help enterprisesdetermine the optimal time of multiple knowledge transfer in the big data environment.
基金supported by the National Natural Science Foundation of China(Grant No.61405227)
文摘A system of jointly transferring time signals with a rate of 1 pulse per second (PPS) and frequency signals of 10 MHz via a dense wavelength division multiplex-based (DWDM) fiber is demonstrated in this paper. The noises of the fiber links are suppressed and compensated for by a controlled fiber delay line. A method of calibrating and characterizing time is described. The 1PPS is synchronized by feed-forward calibrating the fiber delays precisely. The system is experimen- tally examined via a 110 km spooled fiber in laboratory. The frequency stabilities of the user end with compensation are 1.8x 10-14 at 1 s and 2.0x 10-17 at 104 s average time. The calculated uncertainty of time synchronization is 13.1 ps, whereas the direct measurement of the uncertainty is 12 ps. Next, the frequency and 1PPS are transferred via a metropoli- tan area optical fiber network from one central site to two remote sites with distances of 14 km and 110 km. The frequency stabilities of 14 km link reach 3.0x 10-14 averaged in 1 s and 1.4x 10-17 in 104 s respectively; and the stabilities of 110 km link are 8.3 x 10-14 and 1.7 x 10-17, respectively. The accuracies of synchronization are estimated to be 12.3 ps for the 14 km link and 13.1 ps for the 110 km link, respectively.
文摘Efficient real time data exchange over the Internet plays a crucial role in the successful application of web-based systems. In this paper, a data transfer mechanism over the Internet is proposed for real time web based applications. The mechanism incorporates the eXtensible Markup Language (XML) and Hierarchical Data Format (HDF) to provide a flexible and efficient data format. Heterogeneous transfer data is classified into light and heavy data, which are stored using XML and HDF respectively; the HDF data format is then mapped to Java Document Object Model (JDOM) objects in XML in the Java environment. These JDOM data objects are sent across computer networks with the support of the Java Remote Method Invocation (RMI) data transfer infrastructure. Client's defined data priority levels are implemented in RMI, which guides a server to transfer data objects at different priorities. A remote monitoring system for an industrial reactor process simulator is used as a case study to illustrate the proposed data transfer mechanism.
文摘Background Key performance indices such as door-to-balloon times have long been recognized as quality metrics in reducing time to care for patients with acute coronary syndromes(ACS). In the situation where patients do not present to a facility capable of 24/7 percutaneous coronary interventions(PCI) delays in time to therapy can exceed the recommendation of 90 min or less. This study aimed to evaluate the impact of transfers on performance indices for patients diagnosed with ST-segment elevation myocardial infarction(STEMI). Methods Over a seven month collection period, all patients presenting with symptoms suggestive of ACS and admitted for PCI were studied. Patients were divided into dichotomous groups of direct presentations or transfers from a secondary non-PCI capable hospital with key times recorded, including symptom-onset, first hospital and PCI-capable hospital arrival and balloon inflation times to evaluate time of treatment for STEMI patients. Results Of the 87 patients diagnosed with STEMI, transferred patients experienced statistically significant delays in symptom-onset to the PCI-capable hospital(PCI-H) arrival(215 vs. 95 min, P < 0.001), symptom-onset to balloon inflation(225 vs. 160 min, P = 0.009) and first hospital arrival to balloon inflation times(106 vs. 56 min, P < 0.001). Only 28%(n = 9) of transferred patients underwent balloon inflation within 90 min from first hospital arrival, while 60%(n = 19) did within 120 min, although all received balloon inflation within 90 min from arrival at the PCI-H. After controlling for confounding factors of socio-economic status, presentation date/time and diagnostic category, transferred patients experienced an average 162% longer delays from symptom-onset to PCI-H door arrival, and 98% longer delays in symptom-onset to balloon inflation;compared to patients who present directly to the PCI-H. No statistically significant differences were noted between transferred and direct patients when measured from PCI-H door-to-balloon times. Conclusions This study shows that transferred patients experience a greater overall system delay, compared to patients who present directly for PCI, significantly increasing their time to treatment and therefore infarct times. Despite the majority of transfers experiencing pre-hospital activation, their treatment hospital arrival to balloon times are no less than direct presenters after controlling for confounding factors, further compounding the overall delay to therapy.
基金Supported by the National Natural Science Foundations of China (No. 40474001, No. 40274002, No. 40604003).
文摘三个功能的模特儿,多项式,光谱分析,和修改 AR 当模特儿,基于从双向卫星时间和频率转移导出的数据顺序在恰当、预言的钟偏差被学习并且比较。柔韧的当量被使用,它控制无关的观察的重要影响。一些结论证明柔韧的评价的预言精确比 LS 的好。从弄平的观察计算的预言精确比从采样观察计算了高。作为在钟偏差顺序的明显的时期变化的一个计数,多项式模型的预言的价值是难以置信的。光谱分析模型的预言精确是很低的,但是主要时期能是坚定的。6 小时的推测间隔的预言 RMS 是 1 ns 左右,当修改 AR 模型被使用时。
文摘High-precision time transfer plays an important role in the areas of fundamental research and applications. Accompanying w ith the remarkable improvements in the ability of generating and measuring high-accuracy time-frequency signal,seeking for new time-transfer techniques betw een distant clocks w ith much further improved accuracy attracts attentions w orld-w idely. The time-transfer technique based on optical pulses has the highest precision presently,and the further improvement in the accuracy is heavily dependent on the time-domain properties of the pulse as w ell as the sensitivity of the applied measurement on the exchanged pulse. The application of optical frequency comb in time transfer for a precision up to femtosecond level are currently the focus of much interest,and has recently achieved many breakthroughs. Further investigations show that,utilizing quantum techniques,i.e. quantum measurement technique and quantum optical pulse source,can lead to a new limit on the measured timing information. Furthermore,it can be immune from atmospheric parameters,such as pressure,temperature,humidity and so on.Such quantum improvements on time-transfer have a bright prospect in the future applications requiring extremely high-accuracy timing and ranging. The potential achievements w ill form a technical basis for the future realization of sub-femtosecond time transfer system.
基金Funded by the Key Laboratory of Geospace Environment and Geodesy, Ministry of Education, China( No.02 09 0.5) and the National Natural ScienceFoundation of China (No.40174005).
文摘Two methods for smoothing pseudorange observable by Carrier and Doppler are discussed. Then the procedure based on the RINEX observation files is tested using the Ashtech Z-XII3T geodetic receivers driven by a stable external frequency at UNSO. This paper proposes to adapt this procedure for the links between geodetic receivers, in order to take advantage of the P codes available on L 1 and L 2. This new procedure uses the 30-second RINEX observations files, the standard of the International GPS Service (IGS), and processes the ionosphere-free combination of the codes P 1 and P 2; the satellite positions are deduced from the IGS rapid orbits, available after two days.
文摘A self-adaptive precise algorithm in the time domain was employed to solve 2-D nonlinear coupled heat and moisture transfer problems. By expanding variables at a discretized time interval, the variations of variables can be described more precisely,and a nonlinear coupled initial and boundary value problem was converted into a series of recurrent linear boundary value problems which are solved by FE technique. In the computation, no additional assumption and the nonlinear iteration are required, and a criterion for self-adaptive computation is proposed to maintain sufficient computing accuracy for the change sizes of time steps. In the numerical comparison, the variations of material properties with temperature, moisture content, and both temperature and moisture content are taken into account, respectively. Satisfactory results have been obtained, indicating that the proposed approach is capable of dealing with complex nonlinear problems.
文摘Considering the increasing use of information technology with established standards, such as TCP/IP and XML in modern industrial automation, we present a high cost performance solution with FPGA (field programmable gate array) imple-mentation of a novel reliable real-time data transfer system based on EPA (Ethernet for plant automation) protocol and IEEE 1588 standard. This combination can provide more predictable and real-time communication between automation equipments and precise synchronization between devices. The designed EPA system has been verified on Xilinx Spartan3 XC3S1500 and it consumed 75% of the total slices. The experimental results show that the novel industrial control system achieves high synchro-nization precision and provides a 1.59-μs standard deviation between the master device and the slave ones. Such a real-time data transfer system is an excellent candidate for automation equipments which require precise synchronization based on Ethernet at a comparatively low price.
基金Project(2005CB623706) supported by the Major State Basic Research Development Program of ChinaProject(50230310) supported by the National Natural Science Foundation of China
文摘The influence of quench transfer time on the microstructure and mechanical properties of 7055 aluminum alloy with and without zirconium was investigated by tensile properties test,optical microscopy,scanning electron microscopy and transmission electron microscopy.For the Zr-free alloy,the strength increases to the highest value at 20 s with transfer time,and then decreases slightly.The elongation decreases slowly with transfer time within 20 s,and more rapidly after 20 s.For the Zr-containing alloy,prolonging transfer time within 20 s results in slight decrease in the strength and elongation,and rapid drop of which is observed after 20 s.For the Zr-free alloy,prolonging transfer time can increase the percentage of intergranular fracture,which is mainly caused by wide grain boundary precipitate free zone.The failure mode of the Zr-containing alloy is modified from the predominant transgranular void growth and intergranular fracture to transgranular shear and intergranular fracture with increase in the transfer time,which is attributed to the wider grain boundary precipitate free zone and coarse equilibrium η phases in the matrix.
基金National Natural Science Foundation of China(No.81460236)Major Science and Technology Program of Hainan Province(No.ZDKJ2017007)Innovative Project for Postgraduate of Hainan Province(No.Hys2018-281)。
文摘Objective:To explore the effect of different fertilization time after human chorionic gonadotropin(HCG)injection on the outcome of fertilization in vitro fertilization-embryo transfer(IVF-ET).Methods:One thousand one hundred and forty IVF-ET cycles from January 2016 to August 2018 were analyzed retrospectively.According to the different fertilization time after injection of HCG divided into four groups:Group A(38.0 h~39.0 h),Group B(39.1 h~40.0 h),Group C(40.1 h~41.0 h),and Group D(41.1 h~42.0 h).The normal fertilization rate,the normal cleavage rate,the embryo utilization rate,the high-quality embryo rate,the clinical pregnancy rate,the implantation rate,and the spontaneous abortion rate were analyzed among the groups.Then we investigated the effect of different promotion methods on the outcome of fertilization during the optimal fertilization time.Results:There was no significant difference in 2PN cleavage rate,available embryo rate,clinical pregnancy rate,implantation rate and abortion rate among the four groups(P>0.05).The high-quality embryo rate in Group D(44.6%)was the highest,and was significantly different among the four groups(P<0.05).The normal fertilization rate in Group D(71.6%)was the highest,and was significantly different among the four groups(P<0.05).The normal fertilization rate(78.1%)of antagonist group was significantly higher than other groups(P<0.05).Conclusion:The different fertilization time after HCG injection have effects on high-quality embryo rate and normal fertilization rate of patients in IVF-ET.The appropriate fertilization time of patients in IVF-ET was 41 h~42 h after HCG injection in our reproductive center,improved the clinical pregnancy rate and reduced the early abortion rate.The GnRH-ant protocol is superior to other protocol in IVF-ET.
文摘History proves that some countries and regions benefited from international industry transfer, because of international industrial transfer can stimulate their economic growth.Thanks to the manufacturing transfer implemented by EU, USA, Japan and some Asian developed countries in 1980s, China’s economic situation has boomed over 30 years. Textile industry as a traditional industry in China has its own competitive advantage. It can be confirmed that textile industry will play an important role during the fourth Industry transfer period. So, who will be the winner this time?
基金supported in part by Sub Project of National Key Research and Development Plan in 2020.No.2020YFC1511704Beijing Information Science&Technology University.Nos.2020KYNH212,2021CGZH302+1 种基金Beijing Science and Technology Project(Grant No.Z211100004421009)in part by the National Natural Science Foundation of China(Grant No.61971048).
文摘The rapid advancement of Internet of Things(IoT)technology has brought convenience to people’s lives;however further development of IoT faces serious challenges,such as limited energy and shortage of network spectrum resources.To address the above challenges,this study proposes a simultaneous wireless information and power transfer IoT adaptive time slot resource allocation(SIATS)algorithm.First,an adaptive time slot consisting of periods for sensing,information transmission,and energy harvesting is designed to ensure that the minimum energy harvesting requirement ismet while the maximumuplink and downlink throughputs are obtained.Second,the optimal transmit power and channel assignment of the system are obtained using the Lagrangian dual and gradient descent methods,and the optimal time slot assignment is determined for each IoT device such that the sum of the throughput of all devices is maximized.Simulation results show that the SIATS algorithm performs satisfactorily and provides an increase in the throughput by up to 14.4%compared with that of the fixed time slot allocation(FTS)algorithm.In the case of a large noise variance,the SIATS algorithm has good noise immunity,and the total throughput of the IoT devices obtained using the SIATS algorithm can be improved by up to 34.7%compared with that obtained using the FTS algorithm.
基金Project supported by the National Basic Research Program of China(Grant No.2013CB922204)the National Natural Science Foundation of China(Grant Nos.11574115 and 11704146)the Natural Science Foundation of Jilin Province,China(Grant No.20150101063JC)
文摘Time-dependent density functional theory(TDDFT) method is used to investigate the details of the excited state intramolecular proton transfer(ESIPT) process and the mechanism for temperature effect on the Enol*/Keto*emission ratio for the Me2N-substited flavonoid(MNF) compound. The geometric structures of the S0 and S1 states are denoted as the Enol, Enol*, and Keto*. In addition, the absorption and fluorescence peaks are also calculated. It is noted that the calculated large Stokes shift is in good agreement with the experimental result. Furthermore, our results confirm that the ESIPT process happens upon photoexcitation, which is distinctly monitored by the formation and disappearance of the characteristic peaks of infrared(IR) spectra involved in the proton transfer and in the potential energy curves. Besides, the calculations of highest occupied molecular orbital(HOMO) and lowest unoccupied molecular orbital(LUMO) reveal that the electronegativity change of proton acceptor due to the intramolecular charge redistribution in the S1 state induces the ESIPT. Moreover, the thermodynamic calculation for the MNF shows that the Enol*/Keto*emission ratio decreasing with temperature increasing arises from the barrier lowering of ESIPT.
文摘In forecasting real time environmental factors,large data is needed to analyse the pattern behind the data values.Air pollution is a major threat towards developing countries and it is proliferating every year.Many methods in time ser-ies prediction and deep learning models to estimate the severity of air pollution.Each independent variable contributing towards pollution is necessary to analyse the trend behind the air pollution in that particular locality.This approach selects multivariate time series and coalesce a real time updatable autoregressive model to forecast Particulate matter(PM)PM2.5.To perform experimental analysis the data from the Central Pollution Control Board(CPCB)is used.Prediction is car-ried out for Chennai with seven locations and estimated PM’s using the weighted ensemble method.Proposed method for air pollution prediction unveiled effective and moored performance in long term prediction.Dynamic budge with high weighted k-models are used simultaneously and devising an ensemble helps to achieve stable forecasting.Computational time of ensemble decreases with paral-lel processing in each sub model.Weighted ensemble model shows high perfor-mance in long term prediction when compared to the traditional time series models like Vector Auto-Regression(VAR),Autoregressive Integrated with Mov-ing Average(ARIMA),Autoregressive Moving Average with Extended terms(ARMEX).Evaluation metrics like Root Mean Square Error(RMSE),Mean Absolute Error(MAE)and the time to achieve the time series are compared.
文摘The forecasting research literature has developed greatly in recent years as a result of advances in information technology. Financial time-series tasks have made substantial use of machine learning and deep neural networks, but building a prediction model from scratch takes time and computational resources. Transfer learning is growing popular in tackling these constraints of training time and computational resources in several disciplines. This study proposes a hybrid base model for the financial time series prediction employing the recurrent neural network (RNN) and long-short term memory (LSTM) called RNN-LSTM. We used random search to fine-tune the hyperparameters and compared our proposed model to the RNN and LSTM base models and evaluate using the RMSE, MAE, and MAPE metrics. When forecasting Forex currency pairs GBP/USD, USD/ZAR, and AUD/NZD our proposed base model for transfer learning outperforms RNN and LSTM base model with root mean squared errors of 0.007656, 0.165250, and 0.001730 respectively.