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Comparison of the Length of Stay and Medical Expenditures among Japanese Hospitals for Type 2 Diabetes Treatments: The Box-Cox Transformation Model under Heteroscedasticity 被引量:2
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作者 Kazumitsu Nawata Koichi Kawabuchi 《Health》 CAS 2016年第1期49-63,共15页
In this paper, we analyzed length of stay (LOS) in hospitals and medical expenditures for type 2 diabetes patients. LOS was analyzed by the power Box-Cox transformation model when variances differed among hospitals. W... In this paper, we analyzed length of stay (LOS) in hospitals and medical expenditures for type 2 diabetes patients. LOS was analyzed by the power Box-Cox transformation model when variances differed among hospitals. We proposed a new test and consistent estimator. We rejected the ho-moscedasticity of variances among hospitals, and then analyzed the LOS of 12,666 type 2 diabetes patients hospitalized for regular medical treatments collected from 60 general hospitals in Japan. The variables found to affect LOS were age, number of comorbidities and complications, introduced by another hospital, one-week hospitalization, 2010 revision, specific-hospitalization-period (SHP), and principal diseases E11.5, E11.6 and E11.7. There were surprisingly large differences in ALOS among hospitals even after eliminating the influence of characteristics and conditions of patients. We then analyzed daily medical expenditure (DME) by the ordinary least squares methods. The variables that affected DME were LOS, number of comorbidities and complications, acute hospitalization, hospital’s own outpatient, season, introduced by another hospital, one-week hospitalization, 2010 revision, SHP, time trend, and principal diseases E11.2, E11.4 and E117. The DME did not decrease after the SHP. After eliminating the influences of characteristics and conditions of patients, the differences among hospitals were relatively small, 12% of the overall average. LOS is the main determinant of medical expenditures, and new incentives to reduce LOS are needed to control Japanese medical expenditures. Since at least 99% of patients require medical care after leaving the hospital, systems that take proper care of patients for long periods of time after hospitalization are absolutely necessary for efficient treatment of diabetes. 展开更多
关键词 Type 2 Diabetes Medical Expenditure length of Hospital Stay Cox-Box transformation HETEROSCEDASTICITY
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An Econometric Analysis of Hospital Length of Stay for Cataract Operations in Japan by the Box-Cox Transformation Model and Hausman Tests: Evaluation of the 2010 Revision of the Medical Payment System
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作者 Kazumitsu Nawata Koichi Kawabuchi 《Open Journal of Applied Sciences》 2015年第9期559-570,共12页
The Japanese medical costs for cataract treatments reached 270 billion yen in fiscal year 2012. Since the length of stay (LOS) in hospital is much longer than other major countries, controlling the medical costs by re... The Japanese medical costs for cataract treatments reached 270 billion yen in fiscal year 2012. Since the length of stay (LOS) in hospital is much longer than other major countries, controlling the medical costs by reducing LOS becomes an important issue in Japan. In this paper, we evaluated the effects of the 2010 revision of the Japanese medical payment system (DPC/PDPS) on LOS for cataract operations. The Box-Cox transformation model, Nawata’s estimators and Hausman tests were used in the analysis. To evaluate the effects, we analyzed a dataset obtained from 34 DPC hospitals (Hp1-34) where one-eye cataract operations were performed both before (April 2008-March 2010) and after (April 2010-March 2012) the 2010 revision and there were more than 500 patients. The dataset contained information from 32,593 patients. We did not admit the effect of the 2010 revision in this study, and there were large differences LOS among hospitals, even after removing the influences of factors such as patient characteristics and types of principal diseases. 展开更多
关键词 Diagnosis Procedure Combination (DPC) CATARACT length of Stay (LOS) Box-Cox transformATION Model
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数字化转型、创新发展与制造业价值链高质量发展 被引量:7
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作者 齐平 宋威辉 《广东财经大学学报》 CSSCI 北大核心 2024年第1期4-18,共15页
创新驱动发展战略背景下,企业数字化转型对制造业价值链高质量发展具有重要意义。采用2007—2021年沪深A股制造业上市企业数据,从价值链上游度即“强链”和价值链长度即“延链”双重视角,探析企业数字化转型对制造业价值链高质量发展的... 创新驱动发展战略背景下,企业数字化转型对制造业价值链高质量发展具有重要意义。采用2007—2021年沪深A股制造业上市企业数据,从价值链上游度即“强链”和价值链长度即“延链”双重视角,探析企业数字化转型对制造业价值链高质量发展的影响效果、作用机制与异质性特征。研究结果表明:企业数字化转型从“强链”和“延链”两方面推动了制造业价值链高质量发展,且该结论通过了稳健性检验。作用机制检验表明,企业创新发展在此过程中具有显著的正向传导作用。异质性分析表明,在非国有制企业、技术密集型行业、劳动密集型行业和创新引领型城市,企业数字化转型通过“强链”和“延链”推动制造业价值链高质量发展的效果更为显著。为此,在城市层面应健全数字化转型治理体系,在行业层面应加快“新基建”建设进程,促进数字化均衡发展,在企业层面应鼓励以强带弱、协同发展,为企业数字化转型提速增质。 展开更多
关键词 数字化转型 制造业价值链 高质量发展 创新发展 价值链上游度(“强链”) 价值链长度(“延链”)
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基于长度可变密钥的光学图像加密方法
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作者 杨晓云 石峰 《激光杂志》 CAS 北大核心 2024年第2期107-112,共6页
为提升光学图像加密效果,设计了一种基于长度可变密钥的光学图像加密方法。基于混沌方程构成混沌序列均匀化普适算法,运用该算法生成均匀化伪随机序列,以此作为长度可变密钥,经空间光调制器调制后,转换此类密钥为伪随机相位掩模(PRPM),... 为提升光学图像加密效果,设计了一种基于长度可变密钥的光学图像加密方法。基于混沌方程构成混沌序列均匀化普适算法,运用该算法生成均匀化伪随机序列,以此作为长度可变密钥,经空间光调制器调制后,转换此类密钥为伪随机相位掩模(PRPM),运用两个转换后PRPM双重随机相位编码初始光学图像,并结合变形分数傅里叶变换(AFrFT),相位转换编码后光学图像,获得加密光学图像,完成光学图像加密。实验结果显示,该方法可针对不同光学图像生成敏感性与唯一性密钥,实现不同光学图像的加密处理,加密效果显著,加密光学图像的像素频数分布均匀,且解密后光学图像与初始光学图像几乎一致,整体加解密效果理想,可有效保障光学图像的安全性,而且本方法可以在最短3 s的时间内完成光学图像的加密和解密,加解密效率更高,综合效果更佳。 展开更多
关键词 长度可变密钥 光学图像加密 混沌序列 相位掩模 随机相位编码 傅里叶变换
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狭义相对论时空观的图像解译
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作者 缪劲松 胡海云 《物理与工程》 2024年第3期22-27,共6页
狭义相对论的时空观之所以抽象且难以理解,一方面是因为狭义相对论所涉及的时空效应,如同时性的相对性、长度收缩和时间延缓等,在实际中都很难被观测到;另一方面是因为我们很难将这些时空效应同时直观形象地描述出来,并且给出不同参考... 狭义相对论的时空观之所以抽象且难以理解,一方面是因为狭义相对论所涉及的时空效应,如同时性的相对性、长度收缩和时间延缓等,在实际中都很难被观测到;另一方面是因为我们很难将这些时空效应同时直观形象地描述出来,并且给出不同参考系各自观测到的时空效应之间的对应关系。本文针对这一问题,利用图示法将两个参考系在不同时刻观测到的时空图像表示出来,并结合具体数值对他们间的对应关系进行讨论。在图示法中同时考虑了同时性的相对性、长度收缩和时间延缓这三个狭义相对论重要的时空效应,这样可直观形象地看到在一个参考系中得到的观测结果会被另一个参考系所认同,正是这些彼此认同的观测结果构成了狭义相对论的时空观。通过对不同参考系中观察到的时空图像及其相互联系的讨论,可以加深学生对狭义相对论时空效应及洛伦兹变换的物理意义的理解。 展开更多
关键词 狭义相对论 时间延缓 长度收缩 同时性的相对性 洛伦兹变换 时空图像
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基于正态变换的变样本容量Shewhart比例控制图设计
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作者 周思阳 张莹 柯楚贤 《计算机集成制造系统》 EI CSCD 北大核心 2024年第2期610-622,共13页
为了提高Shewhart型比例控制图的监控效率,将其与变样本容量策略结合,提出一种新的比例控制图(VSS Shewhart-RZ*控制图)来监控二元正态变量之比。基于正态变换方法设计了新的比例统计量Z*,以消除样本容量变化对比例控制图设计及使用的... 为了提高Shewhart型比例控制图的监控效率,将其与变样本容量策略结合,提出一种新的比例控制图(VSS Shewhart-RZ*控制图)来监控二元正态变量之比。基于正态变换方法设计了新的比例统计量Z*,以消除样本容量变化对比例控制图设计及使用的不利影响。采用马尔科夫链方法计算了该控制图的平均运行长度和平均样本容量,给出该控制图的参数优化算法。通过仿真分析研究了该控制图的统计性能,并与Shewhart比例控制图进行比较,结果表明VSS Shewhart-RZ*控制图的性能明显优于传统固定样本容量Shewhart比例控制图。 展开更多
关键词 变样本容量 比例分布 平均运行链长 正态变换
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Velocity transformation for compressible wall-bounded turbulence——An approach through the mixing length hypothesis
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作者 Xuke Zhu Yubin Song +1 位作者 Xiaoshuo Yang Zhenhua Xia 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2024年第9期108-125,共18页
In an endeavor to establish a connection between the mean velocity profile in compressible wall-bounded turbulence and its incompressible analogue,a refined version of the Trettel and Larsson's(TL)transformation i... In an endeavor to establish a connection between the mean velocity profile in compressible wall-bounded turbulence and its incompressible analogue,a refined version of the Trettel and Larsson's(TL)transformation is systematically derived and rigorously assessed across diverse flow scenarios.Incorporating the recently proposed intrinsic compressibility effects and modeling the multi-layer structure of mixing lengths,the proposed transformation demonstrates exceptional performance in collapsing 57canonical flow cases,including cooled channel and pipe flows,channel flows with pseudo heat sources,as well as adiabatic and diabatic boundary layer flows.Furthermore,the transformation seamlessly extends to low Reynolds number cooled channel and pipe flows,achieving a level of accuracy unparalleled by other transformations in the current state-of-the-art. 展开更多
关键词 mixing length hypothesis compressible wall-bounded turbulence velocity transformation law of the wall
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植物生长调节剂对中国南瓜杂交种植株生长和雌性性状的影响
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作者 尹杰 王惠林 王子琨 《蔬菜》 2024年第11期36-43,共8页
为探究南瓜雌花的发生规律,调控南瓜开花顺序,降低南瓜母本第1雌花显花节位,简化南瓜杂交制种过程,以制种南瓜杂交种‘JP56’‘JP57’‘JP58’为材料,在苗期对其进行不同组别或浓度乙烯利、甲哌鎓、增瓜灵处理,统计分析南瓜植株生长和... 为探究南瓜雌花的发生规律,调控南瓜开花顺序,降低南瓜母本第1雌花显花节位,简化南瓜杂交制种过程,以制种南瓜杂交种‘JP56’‘JP57’‘JP58’为材料,在苗期对其进行不同组别或浓度乙烯利、甲哌鎓、增瓜灵处理,统计分析南瓜植株生长和性型分化表达情况。结果表明:对南瓜‘JP56’而言,A3处理(3叶1心期喷施0.3 g/L甲哌鎓+1.06 mL/L乙烯利,5叶1心期喷施0.3 g/L甲哌鎓+1.06 mL/L乙烯利+4.0 g/L增瓜灵)第1雌花节位最低,为第9.22节,节长最短,为37.84 mm,均较清水对照显著降低,雌花数较多,为3.39朵,较对照显著增加,为最佳喷药方法;对南瓜‘JP57’而言,A_(2)处理(3叶1心期喷施0.3 g/L甲哌鎓,5叶1心期喷施0.3 g/L甲哌鎓+4.0 g/L增瓜灵)为最佳喷药方法,较对照可显著降低南瓜第1雌花节位至第6.55节,并显著缩短节长至40.20 mm;对南瓜‘JP58’而言,B3处理(3叶1心期喷施乙烯利1.33 mL/L,5叶1心期喷施乙烯利1.33 mL/L+4.0 g/L增瓜灵)较对照可显著增加SPAD值至45.36,显著降低第1雌花节位至第7.33节和显著缩短节长至46.78 mm,为最佳喷药方法,A3处理较对照可显著增加雌花数至3.59朵。生产上可根据具体需求选择相应植物生长调节剂组合的控制方式。 展开更多
关键词 南瓜 生长转化 节长 雌花 乙烯利 甲哌鎓 化学药剂 制种
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电子式电压互感器二次信号准确度研究
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作者 郅娇娇 师进强 《电器与能效管理技术》 2024年第7期69-73,78,共6页
电子式电压互感器在配电设备智能化中具有重要作用,其二次信号准确度是实现配电设备智能化的关键。首先以10 kV电阻型电子式电压互感器为例,构建仿真模型,开展线缆长度对电子式电压互感器二次信号准确度影响的仿真分析;然后搭建电子式... 电子式电压互感器在配电设备智能化中具有重要作用,其二次信号准确度是实现配电设备智能化的关键。首先以10 kV电阻型电子式电压互感器为例,构建仿真模型,开展线缆长度对电子式电压互感器二次信号准确度影响的仿真分析;然后搭建电子式电压互感器准确度测试环境,完成不同长度线缆下的准确度测试。最后,对仿真试验和测试数据进行分析,得到线缆长度对二次信号准确度的影响规律。研究结果对合理选取线缆长度、提高二次信号准确度具有一定实践意义。 展开更多
关键词 电子式电压互感器 二次信号 线缆长度 准确度
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分段拼接坐标系在越岭公路中的局限性分析
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作者 张程虹 《科技资讯》 2024年第5期119-121,共3页
在山区越岭公路工程中,分段投影拼接坐标系与隧道独立坐标系在隧道两端出现了控制点边长差距较大的问题。根据地面边长归化到参考椭球面的长度变形分析拼接坐标系在越岭公路的总体变形,并与以隧道工程平均高程为抵偿投影面的隧道独立坐... 在山区越岭公路工程中,分段投影拼接坐标系与隧道独立坐标系在隧道两端出现了控制点边长差距较大的问题。根据地面边长归化到参考椭球面的长度变形分析拼接坐标系在越岭公路的总体变形,并与以隧道工程平均高程为抵偿投影面的隧道独立坐标系比较,得到分段拼接坐标系与隧道独立坐标系的不一致性。以工程实例总结出分段拼接坐标系在山区公路遇到隧道工程时,其边长变形的局限性,以及在应用拼接坐标系的注意项及其对隧道贯通的影响。 展开更多
关键词 坐标系 坐标转换 控制网 投影面 长度变形 局限性
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Evaluation of Length of Hospital Stay Joining Educational Programs for Type 2 Diabetes Mellitus Patients: Can We Control Medical Costs in Japan? 被引量:4
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作者 Kazumitsu Nawata Koichi Kawabuchi 《Health》 2015年第2期256-269,共14页
Diabetes has become a growing concern in Japan, both medically and financially. The medical cost of diabetes was estimated at 1215 billion yen for fiscal year 2011. We analyzed the length of stay (LOS) in a hospital f... Diabetes has become a growing concern in Japan, both medically and financially. The medical cost of diabetes was estimated at 1215 billion yen for fiscal year 2011. We analyzed the length of stay (LOS) in a hospital for type 2 diabetes mellitus patients who participated in educational programs to determine factors affecting LOS. Data on 991 patients obtained from 28 Red Cross hospitals in 2008 were used. For the analysis, we used the Box-Cox transformation model and Hausman test. The results revealed that patients aged 75 years and above and those with comorbidities and complications were prone to longer LOS. The analysis also revealed significant differences in LOS across the hospitals, even after controlling for patient characteristics. Finally, we applied the least squares method to determine the effects of hospital and regional factors and revealed that patients’ LOS was affected by the region’s average LOS. Regional corporations and networks appeared to be important in improving educational programs. 展开更多
关键词 Medical COST DIABETES Type 2 DIABETES MELLITUS PATIENTS length of Stay (LOS) EDUCATIONAL Program Box-Cox transformation Model
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Optimum Optical Length of the Gas Cell Used for Monitoring Gas-In-Oil with FTIR 被引量:1
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作者 刘先勇 黄风雷 +1 位作者 王霞 周方洁 《Journal of Beijing Institute of Technology》 EI CAS 2003年第1期59-63,共5页
Dedicated experiments are designed to collect the infrared spectra of dissolved gas-in-oil of power transformers. Spectra of diagnostic gases are collected by 3 different laboratorial FTIR spectrometers using 3 differ... Dedicated experiments are designed to collect the infrared spectra of dissolved gas-in-oil of power transformers. Spectra of diagnostic gases are collected by 3 different laboratorial FTIR spectrometers using 3 different gas cells with various sets of equipment parameters. A formula is deduced to calculate the shortest optical length to detect a specific concentration according to measurements on gases with known concentrations near to the minimum detection limit. Collected spectra and calculated results suggested that the optimum optical length of the gas cell should be 150 mm to realize on-line monitoring of diagnostic gases within the required concentration range. At the end, an economic novel design of the gas cell is proposed based on the optimum length. 展开更多
关键词 FTIR gas cell power transformer DGA optical length dissolved gas-in-oil
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Estimation of structural modal parameters by fourier transform with an optimal window 被引量:1
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作者 朱宏平 万信华 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2005年第5期595-598,共4页
An adaptive Fourier Transform (FT) with an optimal window has been proposed for the time-frequency analysis of nonstationary time series. The method allows for a good estimation of both frequency and amplitude of th... An adaptive Fourier Transform (FT) with an optimal window has been proposed for the time-frequency analysis of nonstationary time series. The method allows for a good estimation of both frequency and amplitude of the spectrum and can be easily applied to the general case of time-varying signals. The evaluation of the proposed approach has been performed on measured time-varying signals from a suspension bridge model and a steel frame model whose data have the typical non-stationary characteristics. The numerical results show that the proposed approach can overcome some of the difficulties encountered in the classic Fourier transform technique and can achieve higher computation accuracy. 展开更多
关键词 short-time fourier transform optimal window length modal parameters engineering structures
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The Coherence Cube Computing Method with Self-adaptive Time Window Based on Wavelet Transform 被引量:5
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作者 LI Ying-qi CHE Xiang-jiu 《Computer Aided Drafting,Design and Manufacturing》 2014年第2期10-14,共5页
The coherence cube technology has become an important technology for the seismic attribute interpretation, which extracts the discontinuities of the events through analyzing the similarities of adjacent seismic channe... The coherence cube technology has become an important technology for the seismic attribute interpretation, which extracts the discontinuities of the events through analyzing the similarities of adjacent seismic channels to identify the fault form. The coherence cube technology which uses constant time window lengths can not balance the shallow layers and the deep layers, because the frequency band of seismic data varies with time. When analyzing the shallow layers, the time window will crossover a lot of events, which will lead to weak focusing ability and failure to delineate the details. While the time window will not be long enough for analyzing deep layers, which will lead to low accuracy because the coherences near the zero points of the events are heavily influenced by noise. For solving the problem, we should make a research on the coherence cube technology with self-adaptive time window. This paper determines the sample points&#39; time window lengths in real time by computing the instantaneous frequency bands with Wavelet Transformation, which gives a coherence computing method with the self-adaptive time window lengths. The result shows that the coherence cube technology with self-adaptive time window based on Wavelet Transformation improves the accuracy of fault identification, and supresses the noise effectively. The method combines the advantages of long time window method and short time window method. 展开更多
关键词 coherence cube time window length Wavelet transformation seismic attribute
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Similarity solutions of Prandtl mixing length modelled two dimensional turbulent boundary layer equations
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作者 Bo-Hua Sun 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2022年第3期184-188,共5页
The exact similarity solutions of two dimensional laminar boundary layer were obtained by Blasius in 1908,however,for two dimensional turbulent boundary layers,no Blasius type similarity solutions(special exact soluti... The exact similarity solutions of two dimensional laminar boundary layer were obtained by Blasius in 1908,however,for two dimensional turbulent boundary layers,no Blasius type similarity solutions(special exact solutions)have ever been found.In the light of Blasius’pioneer works,we extend Blasius similarity transformation to the two dimensional turbulent boundary layers,and for a special case of flow modelled by Prandtl mixing-length,we successfully transform the two dimensional turbulent boundary layers partial differential equations into a single ordinary differential equation.The ordinary differential equation is numerically solved and some useful quantities are produced.For numerical calculations,a complete Maple code is provided. 展开更多
关键词 Turbulent boundary layers Laminar boundary layers Similarity transformation Similarity solution Prandtl mixing length Reynolds number
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Cloning and genetic transformation of a novel rice gene OsAPT2
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作者 WENG Man-li1,WANG Wang1,ZHOU Chun-jiang1,QIAO li-xian1,WANG Wei1,FENG Yan-bin1,DUAN De-lin2,DENG Qi-yun3,WANG Bin1(1.The State Key Laboratory of Plant Genomics,Institute of Genetics and Developmental Biology,CAS,Beijing,100101,China 2.Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China 3.Hunan Hybrid Rice Research Center,Changsha 410125,China) 《湖南农业大学学报(自然科学版)》 CAS CSCD 北大核心 2007年第S1期205-,共1页
A novel rice gene OsAPT2,which encodes a putative adenine phosphoribosyl transferase(APRT),was cloned.Its full-length cDNA is 1125bp,composing an ORF encoding 212 amino acid residues and a stop cordon,a 5' UTR of ... A novel rice gene OsAPT2,which encodes a putative adenine phosphoribosyl transferase(APRT),was cloned.Its full-length cDNA is 1125bp,composing an ORF encoding 212 amino acid residues and a stop cordon,a 5' UTR of 123 bp and a 3' UTR of 363 bp.The sequence data have been submitted to the DDBJ/EMBL/GenBank databases(accession number:AY238894).The deduced amino acid sequence of OsAPT2 is highly homologous to those of previously reported APRTs.The genomic OsAPT2 gene contains 7 exons and 6 introns.Its total length is 4758 bp.Then,an antisense expression vector of the full-length OsAPT2 cDNA was constructed and transformed into rice variety Taibei309 by Agrobacterium tumefaciens mediated transformation method.In total,650 T0 transgenic plants were obtained based on both antibiotic screening and specific PCR identification.One hundred individuals of them were selected and planted in Hainan Island.From those 11 male sterile lines with seed-setting rate lower than 3% in bagged spike were obtained.Results suggest that OsAPT2 is involved in male sterility.Nine of the 11 male sterile lines were constitutive sterile lines;two of the 11 male sterile lines were thermo-sensitive genic male sterile lines,which may be useful in hybride rice breeding. 展开更多
关键词 Cloning and genetic transformation of a novel rice gene OsAPT2 length UTR DDBJ CDNA gene
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Very Low Bit-Rate Video Coding by Combining H.264/AVC Standard and 2-D Discrete Wavelet Transform
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作者 Ali Aghagolzadeh Saeed Meshgini +1 位作者 Mehdi Nooshyar Mehdi Aghagolzadeh 《Wireless Sensor Network》 2010年第4期328-336,共9页
In this paper, we propose a new method for very low bit-rate video coding that combines H.264/AVC standard and two-dimensional discrete wavelet transform. In this method, first a two dimensional wavelet transform is a... In this paper, we propose a new method for very low bit-rate video coding that combines H.264/AVC standard and two-dimensional discrete wavelet transform. In this method, first a two dimensional wavelet transform is applied on each video frame independently to extract the low frequency components for each frame and then the low frequency parts of all frames are coded using H.264/AVC codec. On the other hand, the high frequency parts of the video frames are coded by Run Length Coding algorithm, after applying a threshold to neglect the low value coefficients. Experiments show that our proposed method can achieve better rate-distortion performance at very low bit-rate applications below 16 kbits/s compared to applying H.264/AVC standard directly to all frames. Applications of our proposed video coding technique include video telephony, video-conferencing, transmitting or receiving video over half-rate traffic channels of GSM networks. 展开更多
关键词 Video CODING H.264/AVC STANDARD RUN length CODING Two-Dimensional WAVELET transform
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Lorentz Transform in Multi-Dimensional Space
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作者 I. A. Urusovskii 《Journal of Modern Physics》 2012年第11期1749-1756,共8页
It is shown that in Euclidean space with any number of spatial dimensions more than three, the Lorentz transform holds true if the proper time of each elementary particle is proportional to the length of its path in t... It is shown that in Euclidean space with any number of spatial dimensions more than three, the Lorentz transform holds true if the proper time of each elementary particle is proportional to the length of its path in the extra-dimensional subspace, and all elementary particles move at the speed of light in the complete space. The six-dimensional treatment of the Coulomb force of interaction between two charges is given. The electric force is due to the motion of charges in the extra-dimensional subspace and is equal to the corresponding Lorentz force. 展开更多
关键词 LORENTZ transform Euclidean Multi-Dimensional Space COMPTON Wave length De BROGLIE Waves SPIN and Isotopic SPIN HEISENBERG Uncertainty CPT Symmetry COULOMB Force
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基于坐标变换的强间断问题伪弧长算法
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作者 陈泽平 王晨涛 +1 位作者 李坤 马天宝 《兵器装备工程学报》 CAS CSCD 北大核心 2023年第4期68-76,共9页
针对爆炸冲击波数值模拟中经常要面临的强间断奇异性问题,在一维或多维空间中引入弧长参数,通过添加一个约束方程,致使原网格自适应移动变形而能够在强间断区域分布较多的网格点,以此提高大梯度物理量捕捉的分辨率。针对非均匀变形物理... 针对爆炸冲击波数值模拟中经常要面临的强间断奇异性问题,在一维或多维空间中引入弧长参数,通过添加一个约束方程,致使原网格自适应移动变形而能够在强间断区域分布较多的网格点,以此提高大梯度物理量捕捉的分辨率。针对非均匀变形物理空间中格式构造困难的问题,提出了坐标变换,将物理空间中的控制方程映射至均匀正交的弧长计算空间。基于MUSCL格式编写了伪弧长算法相应的一维、二维程序,并对其开展人为解方法验证。将伪弧长算法(PALM)的数值结果同有限体积法进行比较,经过误差分析,验证了伪弧长算法在间断附近具有较高的分辨率。 展开更多
关键词 爆炸冲击波 数值模拟 伪弧长算法 坐标变换 精度验证
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大采长工作面高承压水底板注浆改造技术研究 被引量:5
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作者 段李宏 《矿业安全与环保》 CAS 北大核心 2023年第4期110-115,共6页
为解决陈四楼煤矿大采长工作面高承压水区域底板水害治理难题,在矿井典型2517大采长工作面采用底板注浆改造技术解放受底板太原组灰岩水威胁的煤层。通过资料调研和数据计算,选取改造层位并进行钻孔设计,基于底板注浆改造钻孔的涌水量... 为解决陈四楼煤矿大采长工作面高承压水区域底板水害治理难题,在矿井典型2517大采长工作面采用底板注浆改造技术解放受底板太原组灰岩水威胁的煤层。通过资料调研和数据计算,选取改造层位并进行钻孔设计,基于底板注浆改造钻孔的涌水量和注浆量数据,对各含水层富水性、注浆量、主要可注裂隙、不同级别充水裂隙注浆材料消耗及平均单孔耗浆量规律进行对比分析。结果表明,含水层富水区主要受裂隙、断层和褶皱等构造的影响,L_(10)灰岩和L_(8)灰岩含水层富水性强,分布较均匀,连通性较好,其含水层以中小型和大型裂隙为主且中小型裂隙较多;工作面平均单孔耗浆量约是充水裂隙涌水量的3.4倍。3次物探结果显示,底板注浆改造效果显著,基本解决了陈四楼煤矿高承压水工作面底板突水问题,可为其他矿区矿井水害治理提供借鉴。 展开更多
关键词 大采长工作面 高承压水 灰岩含水层 涌水量 底板注浆改造
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