Assessing the quality of SeaWinds rain measurements

While SeaWinds was designed to measure ocean winds, it can also measure rain over the ocean. SeaWinds on QuikSCAT active measurements of integrated columnar rain rate obtained via simultaneous wind/rain retrieval are evaluated via Monte Carlo simulation and the Crame/spl acute/r-Rao lower bound on estimate accuracy. Although sufficiently accurate in many conditions, the simultaneous wind/rain retrieval method used with SeaWinds on QuikSCAT data is ill-conditioned for certain wind directions and measurement geometries, sometimes yielding spurious rain rates in zero-rain conditions. To assess the validity of SeaWinds-derived rain rates, a simple empirically based rain thresholding scheme is presented, derived from simulated data. Thresholded QuikSCAT rain rates are compared to Tropical Rainfall Measuring Mission Microwave Imager monthly-averaged data, demonstrating good correlation for monthly-averaged data.     

Sea ice mapping method for SeaWinds

A sea ice mapping algorithm for SeaWinds is developed that incorporates statistical and spatial a priori information in a modified maximum a posteriori (MAP) framework. Spatial a priori data are incorporated in the loss terms of a Bayes risk formulation. Conditional distributions and priors for sea ice and ocean statistics are represented as empirical histograms that are forced to conform to a set of expected histograms via principal component filtering. Tuning parameters for the algorithm allow adjustments in the algorithm's performance. Results of the algorithm exhibit high correlation with the Remund-Long sea ice mapping algorithm for SeaWinds and the Special Sensor Microwave/Imager National Aeronautics and Space Administration Team 30% ice edge, and are verified with RADARSAT-1 ScanSAR imagery. The resulting sea ice maps exhibit high edge detail, preserve polynyas and ice bodies disjoint from the primary ice sheet, and thus are suitable for use with wind retrieval and sea ice studies. Principles employed in the algorithm may be of interest in other classification studies.     

An advanced ambiguity selection algorithm for SeaWinds

SeaWinds on QuikSCAT, a spaceborne Ku-band scatterometer, estimates ocean winds via the relationship between the normalized radar backscatter and the vector wind. Scatterometer wind retrieval generates several possible wind vector solutions or ambiguities at each resolution cell, requiring a separate ambiguity selection step to give a unique solution. In processing SeaWinds on QuikSCAT data, the ambiguity selection is "nudged" or initialized using numerical weather prediction winds. We describe a sophisticated new ambiguity selection approach developed at Brigham Young University (BYU) that does not require nudging. The BYU method utilizes a low-order data-driven Karhunen-Loeve wind field model to promote self-consistency. Ambiguity selected winds from the BYU method and standard SeaWinds processing are compared over a set of 102 revs. A manual examination of the data suggests that the nonnudging BYU method selects a more self-consistent wind field in the absence of cyclonic storms. Over a set of cyclonic storm regions, BYU performs better in 9% of the cases and worse in 20% of the cases. Overall, the BYU algorithm selects 93% of the same ambiguities as the standard dataset. This comparison helps validate both nonnudging and nudging techniques and indicates that SeaWinds ambiguity selection can be generally accomplished without nudging.     

基于修正灰色残差算法的风廓线质量控制

为了研究时间域上风廓线数据的质量控制问题,采用后向传播神经网络修正灰色算法残差的方法（BP-GM）,进行了理论分析和实验验证。使用反向传播神经网络训练历史风廓线数据的灰色残差,取得了风廓线质量控制数据。结果表明,当相对误差和后验差比值越小、精度越接近1时,质量控制效果越好;BP-GM法能有效地降低风廓线数据控制残差,提高精度。这一结果对风廓线质量控制是有帮助的。     

Method for extracting epochal information from noisy LP residual

A robust method to extract the epochal information of voiced speech in a noisy condition is proposed. Its excellent performance is demonstrated by testing a synthetic vowel /a/ and a natural vowel /u/, both contaminated by white Gaussian noise with SNR=10 dB. Compared with three other methods, the proposed method produces the most evident peaks at the glottal closure instants     

Cumulative residual entropy: a new measure of information

In this paper, we use the cumulative distribution of a random variable to define its information content and thereby develop an alternative measure of uncertainty that extends Shannon entropy to random variables with continuous distributions. We call this measure cumulative residual entropy (CRE). The salient features of CRE are as follows: 1) it is more general than the Shannon entropy in that its definition is valid in the continuous and discrete domains, 2) it possesses more general mathematical properties than the Shannon entropy, and 3) it can be easily computed from sample data and these computations asymptotically converge to the true values. The properties of CRE and a precise formula relating CRE and Shannon entropy are given in the paper. Finally, we present some applications of CRE to reliability engineering and computer vision.     

测量船质量管理信息系统设计

为了实现测量船质量管理信息化的目的,设计了测量船质量管理信息系统。针对信息利用率不高,信息准确性不高,信息及时性不强及信息共享度不高等问题,采用B/S结构模式,开发了文件管理、记录管理、人员管理三大数据管理模块,按测量船试验工作流程,开发了流程控制、过程管理、数据管理和资源管理等模块,形成横向11个功能模块,纵向2个功能模块,从而实现了测量船质量管理信息化,提高了测量船质量管理水平。     

空间信息网络可靠传输协议研究

设计了与传统TCP相兼容的空间信息网络可靠传输协议STP.协议针对空间环境特点从慢启动算法、拥塞避免算法、快速重传和快速恢复算法等多方面对传统TCP进行综合改进,仿真分析结果表明STP协议比传统TCP性能有较大提升,也比主要针对卫星通信的TCP改进协议的性能有一定改善.能较好地适应空间信息网络中的信息可靠传输需求.     

加强计算机信息系统安全专用产品的质量管理

计算机信息系统安全专用产品的发展,需要产品开发厂商、行业主管部门和产品质量检验机构的共同努力,我们在安全专用的产品方面已经历了从无到有的过程,目前有些产品已发展到过多过滥、市场竞争白热化的程度,为了提高计算机信息系统安全专用产品的质量和规范市场,管理和质量监督必须加强,根据公安部的指示,2002年将加大计算机信息系统安全专用产品的管理力度。     

利用显微激光多普勒测量纳米梁的残余应力

采用基于显微激光多普勒(MicroLD)技术的共振频率法,测量了纳米梁谐振器的残余应力。首先,根据梁的横向弯曲振动理论建立了轴向力作用下固支梁的振动偏微分方程,并根据轴向力的拉压性质解得方程的唯一解形式。随后,由被测梁的应力状况确定可采用最优化方法或数值迭代方法计算残余应力值,并提出结合有限元模态分析方法验证计算结果的正确性。最后,采用MicroLD测振系统对SiC-W固支梁谐振器的幅频响应特性进行了测试。计算结果表明,被测的一组梁的平均残余应力分散性较大,说明加工工艺不能消除结构内的残余应力,且不能控制残余应力的均匀性。     

High quality networking of audio-visual information

An overview of low bit rate coding and the interaction between source coding and channel coding is presented. The interaction of coding with networking in a multiuser environment, including algorithms for robust coding which anticipate imperfect network performance, and techniques of decoding a signal that has traversed an imperfect network are described. The performances of such algorithms are illustrated with examples from speech, audio, and video transmission in the presence of packet losses. The challenges in measuring the quality of service (QOS) in the context of new algorithms for coding and networking and the difficulty of measuring QOS in the networking of multimedia information are discussed     

中央空调系统的水质控制

介绍了中央空调系统安装调试阶段的水质控制方法，采用化学清洗，钝化预膜和阻垢缓蚀处理工艺，使水质达到标准要求。降低铁的腐蚀速度，保证系统正常运行和生物学安全性。     

数据ETL过程中的数据质量控制

分析产生数据质量问题的原因，并对数据质量问题进行了分类，建立数据质量评价的量化标准。提出通过模式集成解决模式层次上的数据质量问题，通过数据清洗解决实例层次上的数据质量问题，并概述了数据清洗算法，提出分四步进行数据ETL数据清洗。     

面向数据库清洗的数据质量控制设计

信息处理技术的不断变革,使每个行业都拥有了许多计算机信息系统,同时也产生了大量的数据。因此能够使数据有效地进行组织的日常运作和判断,要求数据可靠准确是研究的热点,文中提出了一种ETL与数据清洗结合的分布式数据集成工具,将数据清理的技术引入到ETL中,制定数据清洗规则,并基于统计的方法,聚类方法,关联规则的方法等提出数据清洗的算法,并进行比较,提出清洗数据信息的框架,从而提高数据的质量,进行数据清洗评估,认为方法可行有效,具有实际应用意义。     

关于机械加工质量技术控制的研究

本文对于机械加工精度的概念与内容进行介绍,随后对机械加工导致误差的原因进行分析,最后提出相应的提升机械加工精度的工艺对策.     

洁净室的质量控制

主要论述当前洁净室质量控制的重要性，紧迫性，现代质量控制原因，质量保证的条件和基本步骤，以及当前洁净室所面临的质量问题和应该采取的措施。     

Testing exponentiality of the residual life, based on dynamicKullback-Leibler information

This paper proposes a test-of-fit for exponentiality of the residual life (TF-ERL) based on the estimated dynamic Kullback-Leibler information. TF-ERL applies when the exponential parameter is or is not specified under the null hypothesis. Asymptotic properties of TF-ERL are discussed. In particular, the TF-ERL is shown to be a statistically consistent test of the null hypothesis for all alternatives. Small-sample null tail probabilities are derived; critical values are tabulated; and its use is shown in an example. Monte-Carlo simulation is used to compute the power of TF-ERL under various alternatives; it performs well in terms of its power     

Vibration control for adjacent structures using local state information

In this paper, a novel strategy for structural vibration control of multi-structure systems is presented. This strategy pays particular attention to mitigating negative interstructure interactions. Moreover, it is based on recent advances in static output–feedback control, which make possible the efficient computation of decentralized velocity-feedback controllers by solving a single-step optimization problem with Linear Matrix Inequality constraints. To illustrate the main ideas, a local velocity-feedback energy-to-peak controller is designed for the seismic protection of a two-building system. This controller is remarkably effective and extremely simple. Moreover, it can also be implemented by a linear passive damper. To assess the effectiveness of the proposed controller, numerical simulations are conducted with positive results.