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Unveiling the challenges encountered by newly graduated nurses during night shifts:A descriptive qualitative study
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作者 Naomi Kisanuki Miyuki Takase Masako Yamamoto 《International Journal of Nursing Sciences》 CSCD 2024年第4期447-456,共10页
Objectives:Newly graduated nurses commence night shifts during a phase of heightened vulnerability to reality shock,exacerbating the challenges faced by these graduates.Therefore,this study aimed to identify the chall... Objectives:Newly graduated nurses commence night shifts during a phase of heightened vulnerability to reality shock,exacerbating the challenges faced by these graduates.Therefore,this study aimed to identify the challenges experienced by newly graduated nurses when undertaking night shifts in order to help identify a strategy for supporting their adaptation to these shifts.Methods:Semi-structured personal interviews were used to collect data.Fifteen newly graduated nurses were selected to participate in the study by purposive sampling method from November 2021 to March 2022 in one of four general hospitals situated in the southwestern region of Japan.Semi-structured interviews were analyzed by using thematic analysis.Results:The analysis revealedfive central themes and nine subthemes:challenges in task efficiency(task organization challenges,challenges in time-constrained task performance),challenges in responding to patients’changing conditions(challenges in responding to patients’irregular conditions,challenges in responding to nighttime changes in patients’behaviors),challenges in independent practice(challenges in engaging in independent nursing practice,challenges in dealing with unexpected events),challenges in establishing collaborative relationships(challenges in working closely with other staff,challenges in establishing collaborative relationships during night shifts with limited resources),challenges in adapting to shift work(challenges in managing physical conditions for shift work).Conclusions:Newly graduated nurses often encounter challenges in performing their tasks during the transition period.When working night shifts,they face additional hurdles unique to nocturnal duties.Thefindings underscore the necessity for these graduates to develop night shift-specific readiness to effectively navigate the demands inherent in such work schedules. 展开更多
关键词 CHALLENGE Newly graduated nurses Patient care management Qualitative research shift work schedule Night shifts
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Climate-change habitat shifts for the vulnerable endemic oak species(Quercus arkansana Sarg.)
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作者 Suresh Chandra Subedi Seth Drake +1 位作者 Binaya Adhikari Mark V.Coggeshall 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第1期117-127,共11页
Quercus arkansana(Arkansas oak)is at risk of becoming endangered,as the total known population size is represented by a few isolated populations.The potential impact of climate change on this species in the near futur... Quercus arkansana(Arkansas oak)is at risk of becoming endangered,as the total known population size is represented by a few isolated populations.The potential impact of climate change on this species in the near future is high,yet knowledge of its predicted effects is limited.Our study utilized the biomod2 R package to develop habi-tat suitability ensemble models based on bioclimatic and topographic environmental variables and the known loca-tions of current distribution of Q.arkansana.We predicted suitable habitats across three climate change scenarios(SSP1-2.6,SSP2-4.5,and SSP5-8.5)for 2050,2070,and 2090.Our findings reveal that the current suitable habitat for Q.arkansana is approximately 127,881 km^(2) across seven states(Texas,Arkansas,Alabama,Louisiana,Mississippi,Georgia,and Florida);approximately 9.5%is encompassed within state and federally managed protected areas.Our models predict that all current suitable habitats will disap-pear by 2050 due to climate change,resulting in a northward shift into new regions such as Tennessee and Kentucky.The large extent of suitable habitat outside protected areas sug-gests that a species-specific action plan incorporating pro-tected areas and other areas may be crucial for its conserva-tion.Moreover,protection of Q.arkansana habitat against climate change may require locally and regionally focused conservation policies,adaptive management strategies,and educational outreach among local people. 展开更多
关键词 Biomod2 Climate change CONSERVATION Habitat loss Habitat shift Species distribution modeling Oak species
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Calculation and Analysis of TVMS Considering Profile Shifts and Surface Wear Evolution Process of Spur Gear
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作者 Wenzheng Liu Rupeng Zhu +1 位作者 Wenguang Zhou Jingjing Wang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第3期136-150,共15页
Profile shift is a highly effective technique for optimizing the performance of spur gear transmission systems.However,tooth surface wear is inevitable during gear meshing due to inadequate lubrication and long-term o... Profile shift is a highly effective technique for optimizing the performance of spur gear transmission systems.However,tooth surface wear is inevitable during gear meshing due to inadequate lubrication and long-term operation.Both profile shift and tooth surface wear(TSW)can impact the meshing characteristics by altering the involute tooth profile.In this study,a tooth stiffness model of spur gears that incorporates profile shift,TSW,tooth deformation,tooth contact deformation,fillet-foundation deformation,and gear body structure coupling is established.This model efficiently and accurately determines the time-varying mesh stiffness(TVMS).Additionally,an improved wear depth prediction method for spur gears is developed,which takes into consideration the mutually prime teeth numbers and more accurately reflects actual gear meshing conditions.Results show that consideration of the mutual prime of teeth numbers will have a certain impact on the TSW process.Furthermore,the finite element method(FEM)is employed to accurately verify the values of TVMS and load sharing ratio(LSR)of profile-shifted gears and worn gears.This study quantitatively analyzes the effect of profile shift on the surface wear process,which suggests that gear profile shift can partially alleviate the negative effects of TSW.The contribution of this study provides valuable insights into the design and maintenance of spur gear systems. 展开更多
关键词 Profile shift Tooth surface wear Structure coupling effect Improved wear depth prediction method TVMS
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Substituent Effects on 13C NMR and 1H NMR Chemical Shifts of CH=N in Multi-substituted Benzylideneanilines
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作者 曹朝暾 王琳艳 曹晨忠 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2018年第1期45-51,I0001,共8页
Fifty-three samples of multi-substituted benzylideneanilines XArCH=NArYs (abbreviated XBAYs) were synthesized and their NMR spectra were determined. An extensional study of substituent effects on the 1H NMR chemical... Fifty-three samples of multi-substituted benzylideneanilines XArCH=NArYs (abbreviated XBAYs) were synthesized and their NMR spectra were determined. An extensional study of substituent effects on the 1H NMR chemical shifts (δH(CH=N)) and 13C NMR chemical shifts (δc(CH=N)) of the CH=N bridging group from di-substituted to multi-substituted XBAYs was made based on a total of 182 samples of XBAYs, together with the NMR data of other 129 samples of di-substituted XBAYs quoted from literatures. The results show thatthe substituent specific cross-interaction effect parameter (△(∑σ)2) plays an important role in quantifying the δc(CH=N) values of XBAYs, but it is negligible for quantifying the δH (CH=N) values; the other substituent parameters also present different influences on the δc (CH=N) and (δH (CH=N). On the whole, the contributions of X and Y to the δc (CH=N) of XBAYs are balanced, but the δH(CH=N) values of XBAYs mainly rely on the contributions of X. 展开更多
关键词 Multi-substituted benzylideneanilines Substituent effects 1H NMR chemicalshifts 13C NMR chemical shifts Substituent specific cross-interaction effect
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Spectral Characterization of Hyponormal Weighted Shifts
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作者 王公宝 《Chinese Quarterly Journal of Mathematics》 CSCD 2002年第2期65-70,共6页
The complete characterizations of the spectra and their various parts of hyponormal unilateral and bilateral weighted shifts are presented respectively in this paper. The results obtained here generalize the correspon... The complete characterizations of the spectra and their various parts of hyponormal unilateral and bilateral weighted shifts are presented respectively in this paper. The results obtained here generalize the corresponding work of the references. 展开更多
关键词 Hilbert space hyponormal operators weighted shifts SPECTRUM
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k-Shifts算法在一类批量计划编制中的应用
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作者 李聪 杜斌 何骏 《控制工程》 CSCD 2008年第S1期148-150,154,共4页
分析了冶金行业常见的一类批量计划编制问题,给出了这类组合优化问题的数学模型;分析并证明了传统k-Opt算法不适合这类非对称性组合优化问题,提出将1-Shift算法扩展为k-Shifts算法,为求得近优解提供保证;缩小了k-Shifts算法的搜索空间,... 分析了冶金行业常见的一类批量计划编制问题,给出了这类组合优化问题的数学模型;分析并证明了传统k-Opt算法不适合这类非对称性组合优化问题,提出将1-Shift算法扩展为k-Shifts算法,为求得近优解提供保证;缩小了k-Shifts算法的搜索空间,大大降低了k-Shift算法时间复杂度;改进了优化目标评价函数,大幅度提高求解性能。改进后的算法成功地解决了这一类NP问题,实验证明了在多项式时间复杂度内可以求出近似于问题全局最优值的解。 展开更多
关键词 k-shifts算法 批量计划编制 启发式搜索 组合最优化
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Mean Shift跟踪算法创新实验项目设计
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作者 王辉 王雪莹 于立君 《实验室科学》 2024年第1期12-16,共5页
视频跟踪算法是计算机视觉实践课程中比较受关注的实验项目。针对突变情况下传统Mean Shift跟踪算法无法实时准确跟踪的问题,设计了基于模板更新和线性预估的Mean Shift跟踪算法创新实验项目。在模板更新策略下,引入背景模板,通过将原... 视频跟踪算法是计算机视觉实践课程中比较受关注的实验项目。针对突变情况下传统Mean Shift跟踪算法无法实时准确跟踪的问题,设计了基于模板更新和线性预估的Mean Shift跟踪算法创新实验项目。在模板更新策略下,引入背景模板,通过将原目标模板和背景模板与设定的阈值进行比较来对干扰因素进行判定,当干扰因素判定目标受到遮挡时,引入线性预估方程进行目标位置预测,有效解决目标在遮挡情况下跟踪丢失的问题。通过对测试视频的跟踪效果和性能进行对比分析,验证了算法在突变情况下相较于传统算法具有更好的抗干扰能力。以算法创新设计为核心,通过开放性创新实验项目的选题、设计、答辩、反馈的闭环实验过程,有效提高了学生算法创新设计能力。 展开更多
关键词 Mean shift跟踪算法 模板更新 线性预估 抗干扰
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Regime Shifts in the North Pacific Simulated by a COADS-driven Isopycnal Model 被引量:9
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作者 王东晓 王佳 +1 位作者 吴立新 刘征宇 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2003年第5期743-754,共12页
The Miami Isopycnal Coordinate Ocean Model (MICOM) is adopted to simulate the intevdecadal variability in the Pacific Ocean with most emphasis on regime shifts in the North Pacific. The computational domain covers 60&... The Miami Isopycnal Coordinate Ocean Model (MICOM) is adopted to simulate the intevdecadal variability in the Pacific Ocean with most emphasis on regime shifts in the North Pacific. The computational domain covers 60°N to 40°S with an enclosed boundary condition for momentum flux, whereas there are thermohalirie fluxes across the southern end as a restoring term. In addition, sea surface salinity of the model relaxes to the climatological season cycle, which results in climatological fresh water fluxes. Surface forcing functions from January 1945 through December 1998 are derived from the Comprehensive Ocean and Atmospheric Data Set (COADS). Such a numerical experiment reproduces the observed evolution of the interdecadal variability in the heat content over the upper 400-m layer by a two-year lag. Subduction that occurs at the ventilated thermocline in the central North Pacific is also been simulated and the subducted signals propagate from 35°N to 25°N, taking about 8 to 10 years, in agreement with the expendable Bathy Thermograph observation over recent decades. Interdecadal signals take a southwest-ward and downward path rather than westward propagation, meaning they are less associated with the baroclinic planetary waves. During travel, the signals appear to conserve potential vorticity. Therefore, the ventilated thermocline and related subduction are probably the fundamental physics for interdecadal variability in the mid-latitude subtropics of the North Pacific. 展开更多
关键词 North Pacific ventilated thermocline regime shift isopycnal model
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Isotope Shifts of Nitrogen around 800 nm
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作者 白皎 汪海玲 +1 位作者 倪雪 邓伦华 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2016年第5期527-532,I0001,共7页
The Doppler-limited absorption spectra of ^14N and ^15N atoms were measured around 800 nm using concentration modulation spectroscopy to study their isotope shifts. The nitrogen atoms were generated by discharging mol... The Doppler-limited absorption spectra of ^14N and ^15N atoms were measured around 800 nm using concentration modulation spectroscopy to study their isotope shifts. The nitrogen atoms were generated by discharging molecular nitrogen buffered with helium in a homemade discharge tube. The isotope shifts of four multiplets (3s^4PJ→3p^4D^oJ, 3s^4PJ→3p^4P^oJ, 3s^2DJ→5s^2P^oJ, and 3p^2P^oJ→5s^2D^oJ) were measured and their J-dependent specific mass shifts were observed and discussed. 展开更多
关键词 Doppler-limited absorption spectra Isotope shifts Specific mass shifts J-dependence
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ENTIRE FUNCTIONS SHARING ONE SMALL FUNCTION CM WITH THEIR SHIFTS AND DIFFERENCE OPERATORS 被引量:3
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作者 崔宁 陈宗煊 《Acta Mathematica Scientia》 SCIE CSCD 2017年第3期786-798,共13页
In this article, we mainly devote to proving uniqueness results for entire functionssharing one small function CM with their shift and difference operator simultaneously. Letf(z) be a nonconstant entire function of ... In this article, we mainly devote to proving uniqueness results for entire functionssharing one small function CM with their shift and difference operator simultaneously. Letf(z) be a nonconstant entire function of finite order, c be a nonzero finite complex constant, and n be a positive integer. If f(z), f(z+c), and △n cf(z) share 0 CM, then f(z+c)≡Af(z), where A(≠0) is a complex constant. Moreover, let a(z), b(z)( O) ∈ S(f) be periodic entire functions with period c and if f(z) - a(z), f(z + c) - a(z), △cn f(z) - b(z) share 0 CM, then f(z + c) ≡ f(z). 展开更多
关键词 Entire function shifts difference operators shared values
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Prediction of the ^(13)C NMR Chemical Shifts of Stilbene Analogues by GIAO Method 被引量:2
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作者 XIE Hui-ding LI Yu-peng QIU Kai-xiong LIU Bo CHEN Ya-ping 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2010年第6期1016-1019,共4页
After the geometry optimization at B3LYP/6-31+G(d,p) level,the calculations of the NMR chemical shifts of a series of stilbene analogues were carried out by means of Gauge Including Atomic Orbitals(GIAO) method a... After the geometry optimization at B3LYP/6-31+G(d,p) level,the calculations of the NMR chemical shifts of a series of stilbene analogues were carried out by means of Gauge Including Atomic Orbitals(GIAO) method at HF/6-31+G(d) level and B3LYP/6-311G+(2d,p) level,respectively.The 13C NMR chemical shifts calculated at both HF/6-31+G(d) and B3LYP/6-31+G(d,p) levels are in agreement with the observed values.By virtue of a series of linear correction equations(δpred.=a+bδcalcd.) of the 13C chemical shifts,accurate prediction of 13C chemical shifts was achieved for the new stilbene compounds.For the 13C NMR chemical shifts calculated at HF/6-31+G(d) level,the linear correlation of δpred.with δexptl.is excellent,and the square of correlation coefficient,r2,is 0.9985.The maximum absolute difference between δpred.and δexptl.,Δδ,is 2.3,and the root-mean-square error between δpred.and δexptl.is 0.98.In the meantime,for those obtained at B3LYP/6-31+G(d,p) level,the linear correlation of δpred.with δexptl.is also excellent,and the square of correlation coefficient,r2,is up to 0.9987.The maximum absolute difference between δpred.and δexptl.,Δδ,is 2.2,and the root-mean-square error between δpred.and δexptl.is only 0.88. 展开更多
关键词 Stilbene analogue ^13C NMR chemical shift PREDICTION
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Improved Evaluation of BBR and Collisional Frequency Shifts of NIM-Sr2 with 7.2×10^(-18)Total Uncertainty 被引量:4
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作者 Bing-Kun Lu Zhen Sun +7 位作者 Tao Yang Yi-Ge Lin Qiang Wang Ye Li Fei Meng Bai-Ke Lin Tian-Chu Li Zhan-Jun Fang 《Chinese Physics Letters》 SCIE EI CAS CSCD 2022年第8期22-27,共6页
NIM-Sr2 optical lattice clock has been developed on the Changping campus of National Institute of Metrology(NIM).Considering the limitations in NIM-Sr1,several improved parts have been designed including a differentia... NIM-Sr2 optical lattice clock has been developed on the Changping campus of National Institute of Metrology(NIM).Considering the limitations in NIM-Sr1,several improved parts have been designed including a differential pumping stage in the vacuum system,a permanent magnet Zeeman slower,water-cooled anti-Helmholtz coils,an extended viewport for Zeeman slower,etc.A clock laser with a short-time stability better than 3×10^(-16)is realized based on a self-designed 30-cm-long ultra-low expansion cavity.The systematic frequency shift has been evaluated to an uncertainty of 7.2×10^(-18),with the uncertainty of BBR shift and the collisional frequency shift being an order of magnitude lower than the last evaluation of NIM-Sr1. 展开更多
关键词 PUMPING SLOWER shift
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Reductivity and bundle shifts 被引量:1
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作者 XU An-jian 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2019年第1期27-32,共6页
For the Hardy space H_E^2(R) over a ?at unitary vector bundle E on a ?nitely connected domain R, let TE be the bundle shift as [3]. If B is a reductive algebra containing every operator ψ(TE) for any rational functi... For the Hardy space H_E^2(R) over a ?at unitary vector bundle E on a ?nitely connected domain R, let TE be the bundle shift as [3]. If B is a reductive algebra containing every operator ψ(TE) for any rational function ψ with poles outside of R, then B is self adjoint. 展开更多
关键词 reductivity BUNDLE shift multiply-connected DOMAIN
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Prediction of the ^(13)C NMR Chemical Shifts of Fluorenone Analogues by the GIAO Method 被引量:2
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作者 李玉鹏 谢惠定 +2 位作者 黄燕 郭蕴苹 章小丽 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2010年第5期682-685,共4页
After the geometry optimization at B3LYP/6-31+G(d,p) level,the NMR calcula-tions of a series of fluorenone analogues have been carried out by GIAO method at HF/6-31+G(d) level and B3LYP/6-311G+(2d,p) level,re... After the geometry optimization at B3LYP/6-31+G(d,p) level,the NMR calcula-tions of a series of fluorenone analogues have been carried out by GIAO method at HF/6-31+G(d) level and B3LYP/6-311G+(2d,p) level,respectively.The 13C NMR chemical shifts calculated at HF/6-31+G(d) level show better agreement with the observed values.By a series of linear correction equations (δpred=a + bδcalc),accurate prediction of 13C chemical shifts was achieved for the new fluorenone compound.The linear correlation of δpred with δexptl is excellent,and the square of correlation coefficient,r2,is up to 0.994.The maximum absolute difference between δpred and δexptl,Δδ,is 4.6 ppm,and the root-mean-square error between δpred and δexptl is only 2.6 ppm. 展开更多
关键词 fluorenone analogues 13C NMR chemical shifts PREDICTION
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Relative Chemical Shifts for Obtaining Accurate Chemical Shifts of Hydrogen Atoms in CH Groups
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作者 张荣一 李俊 吴文娟 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2014年第2期240-242,I0004,共4页
Accurate chemical shifts of hydrogen atoms in CH groups are difficult to obtain. To solve this problem, relative chemical shifts are introduced. Internal and external standard methods were used to measure the chemical... Accurate chemical shifts of hydrogen atoms in CH groups are difficult to obtain. To solve this problem, relative chemical shifts are introduced. Internal and external standard methods were used to measure the chemical shifts in a whole-concentration of N-methylacetamide- water system. Determination of the chemical shifts of hydrogen atoms, especially those of CH groups, according to the two methods yielded significant differences. Relative chemical shifts were proven to be independent of the reference and may be applied to other systems. 展开更多
关键词 Relative chemical shift CH group Internal and external method
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An Orbit Determination Using SGP4 Propagator and Doppler Shifts for CubeSats 被引量:2
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作者 Wesam M.Elmahy Zhang Xiang +1 位作者 Lu Zhengliang Liao Wenhe 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2018年第3期472-482,共11页
The two line elements(TLEs),released by the North American Aerospace Defense Command(NORAD),are chosen for CubeSats' mission operators.Unfortunately,they have errors and other accompanied problems,which cause larg... The two line elements(TLEs),released by the North American Aerospace Defense Command(NORAD),are chosen for CubeSats' mission operators.Unfortunately,they have errors and other accompanied problems,which cause large deviations in the in-track component.When a TLE value is available at a certain epoch,the dominant error is the angular error.It is proposed to correct the angular error by solving-for the mean argument of latitude at the desired epoch.A batch least squares technique and range rate measurements are used for the correction process.With the assistance of satellite tool kit(STK)software and Matlab,a simulation to verify the orbit determination(OD)technique is implemented.This paper provides an angular correction low cost OD method and presents a complete analysis for various test cases.This approach maintains high accuracy in cross-track and radial and makes great improvement in in-track at the same time,but it is exclusive for circular orbits.When it is applied to an elliptical orbit,the error will be unacceptable.Therefore,the angular error is corrected using the longitude of periapsis which totally mitigates the error at the epoch under consideration.For inclinations less than 20 o,the mean longitude is preferred for the angular correction as it provides more accuracy compared with the mean argument of latitude. 展开更多
关键词 CUBESAT low earth orbit(LEO) orbit determination doppler shift two line elements(TLEs)
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DAO to HANOI via DeSci: AI Paradigm Shifts from AlphaGo to ChatGPT 被引量:16
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作者 Qinghai Miao Wenbo Zheng +3 位作者 Yisheng Lv Min Huang Wenwen Ding Fei-Yue Wang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第4期877-897,共21页
From AlphaGo to ChatGPT,the field of AI has launched a series of remarkable achievements in recent years.Analyzing,comparing,and summarizing these achievements at the paradigm level is important for future AI innovati... From AlphaGo to ChatGPT,the field of AI has launched a series of remarkable achievements in recent years.Analyzing,comparing,and summarizing these achievements at the paradigm level is important for future AI innovation,but has not received sufficient attention.In this paper,we give an overview and perspective on machine learning paradigms.First,we propose a paradigm taxonomy with three levels and seven dimensions from a knowledge perspective.Accordingly,we give an overview on three basic and twelve extended learning paradigms,such as Ensemble Learning,Transfer Learning,etc.,with figures in unified style.We further analyze three advanced paradigms,i.e.,AlphaGo,AlphaFold and ChatGPT.Second,to enable more efficient and effective scientific discovery,we propose to build a new ecosystem that drives AI paradigm shifts through the decentralized science(DeSci)movement based on decentralized autonomous organization(DAO).To this end,we design the Hanoi framework,which integrates human factors,parallel intelligence based on a combination of artificial systems and the natural world,and the DAO to inspire AI innovations. 展开更多
关键词 ChatGPT decentralized science(DeSci) decentralized autonomous organization(DAO) machine learning paradigm shift
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Iterative Learning Control for a Class of Linear Continuous-time Switched Systems with Fixed Initial Shifts 被引量:2
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作者 xu guang-zhao fu qin +3 位作者 du li-li wu jian-rong yu peng-fei li yong 《Communications in Mathematical Research》 CSCD 2018年第4期309-328,共20页
This paper deals with the problem of iterative learning control for a class of linear continuous-time switched systems in the presence of a fixed initial shift. Here, the considered switched systems are operated durin... This paper deals with the problem of iterative learning control for a class of linear continuous-time switched systems in the presence of a fixed initial shift. Here, the considered switched systems are operated during a finite time interval repetitively. According to the characteristics of the systems, a PD-type learning scheme is proposed for such switched systems with arbitrary switching rules, and the corresponding output limiting trajectories under the action of the PD-type learning scheme are given. Based on the contraction mapping method, it is shown that this scheme can guarantee the outputs of the systems converge uniformly to the output limiting trajectories of the systems over the whole time interval. Furthermore, the initial rectifying strategies are applied to the systems for eliminating the effect of the fixed initial shift. When the learning scheme is applied to the systems, the outputs of the systems can converge to the desired reference trajectories over a pre-specified interval. Finally, simulation examples illustrate the effectiveness of the proposed method. 展开更多
关键词 iterative learning control switched system PD-type learning scheme fixed initial shift output limiting trajectory
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Analysis of the influence of various effects on frequency shifts of the acetylene saturated absorption lines 被引量:1
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作者 董磊 张雷 +2 位作者 窦海鹏 尹王保 贾锁堂 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第1期152-157,共6页
Frequency shifts of the acetylene saturated absorption lines at 1.5μm with temperature, gas pressure and laser power have been investigated in detail. The second-order Doppler effect, the recoil effect, the Zeeman ef... Frequency shifts of the acetylene saturated absorption lines at 1.5μm with temperature, gas pressure and laser power have been investigated in detail. The second-order Doppler effect, the recoil effect, the Zeeman effect, the pressure shift and the power shift are taken into consideration. The magnitudes of those shifts caused by various effects are evaluated. In order to reproduce the stability of 5.7 × 10^-14 obtained by Edwards, all necessary conditions are given. The results show that when there is a larger external magnetic field, the Zeeman shift could not be neglected, so that the shield should be employed. And the design of a long cavity is advantageous to reduce the influence of the second-order Doppler effect. The results also show that at least 4-2.5℃ temperature control for cavity can effectively prevent several effects and improve the frequency stability. 展开更多
关键词 frequency shifts sub-Doppler spectroscopy ACETYLENE cavity-enhanced absorption technique
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Paradigm Shifts or Methodology Changes ? Think Twice Before You Put Paradigms into Practice 被引量:1
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作者 Cormspondence: Yang Yonglin,Department Of Foreign Languages,Tsinghua University Beliing,P. R. China 《现代外语》 CSSCI 北大核心 1999年第4期420-420,共1页
ThepresentpaperaddressestheapplicabilityofKuhn'stheoryofparadigmshiftsandscientificrevolutionstothefieldoflanguageteaching.First,itillustratestheconceptionofparadigmshiftsandscientificrevolutions.Andthen,itsetsupt... ThepresentpaperaddressestheapplicabilityofKuhn'stheoryofparadigmshiftsandscientificrevolutionstothefieldoflanguageteaching.First,itillustratestheconceptionofparadigmshiftsandscientificrevolutions.Andthen,itsetsuptwotestsforexaminingtheissueofwhetherK... 展开更多
关键词 linguistic theory PSYCHOLOGY paradigm shifts scientific REVOLUTIONS language teaching ECLECTICISM METHODOLOGY
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