11 resultados para Radiographic standardization
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
从计算机技术的角度出发,对植物形态学信息处理和应用,构成本文的思想,文中简略同顾了植物形态学术语的标准化的历史发展过程,对当前世界范围内在此领域的工作也作了概要般的总结,论述了计算机技术用十植物学应用和研究的重要性并提出了我国在此领域内开展工作的紧迫性和必要性。计算机的资源限制及植物信息特有的复杂性是这一领域发展的困难。因此,如何贮存植物信息?如何操作加工应用?才能充分利用计算机资源和植物信息资源成为本领域的核心问题。 本文基于上面的考虑,对植物形态学信息从基本的信息单位植物形态学术语出发,探求其分类结构,并从计算机技术的编码理论方面进行探讨.力图求得一个标准化的植物形态学描述分类群的术语编码集,提供一种实现描述的方法,并试验性地给出一种描述规范和格式,简单讨论一下实现语言处理,机器鉴定、数量分类的可能性,最后简单分析和对比了本工作和国际上的类似工作,并对本领域进行了简单的展望。
Resumo:
A-new-carrier-frequency offset estimation scheme in orthogonal frequency division multiplexing (OFDM) is proposed. The scheme includes coarse frequency offset estimation and fine frequency offset estimation. The coarse frequency offset estimation method we present is a improvement of Zhang's method. The estimation range of the new method is as large as the overall signal-band width. A new fine frequency offset estimation algorithm is also discussed in this paper. The new algorithm has a better performance than the Schmidt's algorithm. The system we use to calculate and simulate is based on the high rate WLAN standard adopted by the IEEE 802.11 standardization group. Numerical results are presented to demonstrate the performance of the proposed algorithm.
Resumo:
Linux系统的输入法存在多种框架和实现,以往的标准化努力没有给出令人满意的结果,输入法引擎(IME)接口标准化采用了新的路线,有助于开发可适用于不同框架的IME.在总结归纳现有输入法框架基础上,分析了对IME接口进行标准化的基本原理,详细说明了IME接口标准的重要特性和设计原则;相关的实体被划分到4个部分,使用时序图对不同部分的交互进行了细致的分析.标准的可行性需要IME示例实现进行证明,针对覆盖标准不同方面的3个示例实现给出了简要说明,其设计和实践可供开发符合标准的IME时参考.最后,对该标准的应用前景和进一步研究方向做出了展望.
Resumo:
介绍了国际上Linux标准化相关组织及其发布标准的基本情况,并进行了简单分析。以此为据,为国内的Linux标准化工作提出一些基础性的建议。
Resumo:
“Dissolved” (< 0.4 μm filtered) and “total dissolvable” (unfiltered) trace element samples were collected using “clean” sampling techniques from four vertical profiles in the eastern Atlantic Ocean on the first IOC Trace Metals Baseline expedition. The analytical results obtained by 9 participating laboratories for Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb, and Se on samples from station 4 in the northeast Atlantic have been evaluated with respect to accuracy and precision (intercomparability). The data variability among the reporting laboratories was expressed as 2 × SD for a given element and depth, and was comparable to the 95% confidence interval reported for the NASS seawater reference standards (representing analytical variability only). The discrepancies between reporting laboratories appear to be due to inaccuracies in standardization (analytical calibration), blank correction, and/or extraction efficiency corrections.Several of the sampling bottles used at this station were not adequately pre-cleaned (anomalous Pb results). The sample filtration process did not appear to have been a source of contamination for either dissolved or particulate trace elements. The trace metal profiles agree in general with previously reported profiles from the Atlantic Ocean. We conclude that the sampling and analytical methods we have employed for this effort, while still in need of improvement, are sufficient for obtaining accurate concentration data on most trace metals in the major water masses of the oceans, and to enable some evaluation of the biogeochemical cycling of the metals.
Resumo:
Numerous measures are used in the literature to describe the grain-size distribution of sediments. Consideration of these measures indicates that parameters computed from quartiles may not be as significant as those based on more rigorous statistical concepts. In addition, the lack of standardization of descriptive measures has resulted in limited application of the findings from one locality to another. The use of five parameters that serve as approximate graphic analogies to the moment measures commonly employed in statistics is recommended. The parameters are computed from five percentile diameters obtained from the cumulative size-frequency curve of a sediment. They include the mean (or median) diameter, standard deviation, kurtosis, and two measures of skewness, the second measure being sensitive to skew properties of the "tails" of the sediment distribution. If the five descriptive measures are listed for a sediment, it is possible to compute the five percentile diameters on which they are based (phi 5 , phi 16 , phi 50 , phi 84 , and phi 95 ), and hence five significant points on the cumulative carve of the sediment. This increases the value of the data listed for a sediment in a report, and in many cases eliminates the necessity of including the complete mechanical analysis of the sediment. The degree of correlation of the graphic parameters to the corresponding moment measures decreases as the distribution becomes more skew. However, for a fairly wide range of distributions, the first three moment measures can be ascertained from the graphic parameters with about the same degree of accuracy as is obtained by computing rough moment measures.
Resumo:
在分析国际无线寻呼标准编码POCSAG(Post Office Code Standardization Adviso-ry Group)码的基础上,利用现有BB机的射频接收部分,以MCS-51单片微处理器为主体,设计了一个最小系统,实现对无线寻呼信号的射频解调、同步接收、通信纠错等处理,然后通过RS-232C标准串行接口传送到IBM-PC微型计算机中,进行信息译码,并在微机监视器上实时显示.
Resumo:
Correction of spectral overlap interference in inductively coupled plasma atomic emission spectrometry by factor analysis is attempted. For the spectral overlap of two known lines, a data matrix can be composed from one or two pure spectra and a spectrum of the mixture. The data matrix is decomposed into a spectra matrix and a concentration matrix by target transformation factor analysis. The component concentration of interest in a binary mixture is obtained from the concentration matrix and interference from the other component is eliminated. This method is applied to correcting spectral interference of yttrium on the determination of copper and aluminium: satisfactory results are obtained. This method may also be applied to correcting spectral overlap interference for more than two lines. Like other methods of correcting spectral interferences, factor analysis can only be used for additive spectral overlap. Results obtained from measurements on copper/yttrium mixtures with different white noise added show that random errors in measurement data do not significantly affect the results of the correction method.
Resumo:
阐述了可信赖机器翻译( TMT)的基本概念, TMT七原则和七判据, TMT与术语标准化的关系,并讨论了对外来词的音译和双语联合表示法的应用等问题。