基于JPEG2000的ROI改进编码算法研究

在许多的图像应用中，基于感兴趣区域（ROI）图像编码技术占有重要地位。对图像压缩和传输处理，总是希望自己所感兴趣的图像区域能够得到相对于背景（BG）区域更好的压缩效果。在JPEG2000中采用了General Scaling Based Method 和 Maxshift Method的ROI编码技术。最重要平移和逐个平移法在最大位移法的基础上进行了改进、实验结果表明，该方法可行且性能优越。     

On the consistency in variations of the South China Sea Warm Pool as revealed by three sea surface temperature datasets

The areal and intensity indices of the South China Sea Warm Pool (SCSWP) derived from three datasets, the Advanced Very High Resolution Radiometer (AVHRR), Tropical Rainfall Measuring Mission's Microwave Imager (TMI) and Optimum Interpolation Version 2 (OI.v2) sea surface temperature (SST), are generally consistent with each other at monthly, seasonal and interannual scales. However, the three records are different in some cases. First, minor differences among the monthly records of intensity index are observed in the period July to September. Secondly, the interannual records of SCSWP intensity derived from AVHRR and OI.v2 are different in autumn during the period 1990-1996. The reason is not yet clear and nor is it clear which record best represents fluctuations in SCSWP intensity. These suggest that various drawbacks of the three datasets, such as low resolution of OI.v2, and cloud and rain contamination on AVHRR and TMI data, would be serious enough to allow deviation from each other to appear. Merging AVHRR and TMI SST data might be the way leading to a more convincing time series of SCSWP. In addition, changes of areal and intensity indices are not always consistent with each other, for example, they have different monthly patterns. Although the three interannual records of intensity index in three seasons all capture the main Multivariate ENSO Index (MEI) signals at a half-year lag, only those which are in the summer significantly correlated with MEI.     

咪唑啉自组装单分子膜在镁合金AZ91D表面的防腐蚀研究

用咪唑啉水溶液在镁合金(AZ91D)电极表面制备了自组装单分子膜，研究了该组装膜在0.2 mol/L NaCl中对AZ91D的缓蚀作用.通过接触角、FT-IR、EIS和线性极化等方法对自组装膜的形成过程和保护效率进行了研究，得出最佳的咪唑啉组装液浓度为5×10-4mol/L和最佳组装时间为72 h下的缓蚀效率.     

新型阻燃聚醚多元醇的合成研究

以 3 (2 ,4 ,6 三溴苯氧基 )环氧丙烷为阻燃单体 ,N ,N 二 (2 羟基乙基 ) 2 ,4 ,6 三溴苯胺为起始剂 ,合成了具有阻燃特性的聚醚多元醇。着重考察了反应物料比、投料方式、反应时间等因素对阻燃聚醚多元醇物理性质及收率的影响。应用试验结果表明 :适合制造软泡材料的阻燃聚醚多元醇原料配方是 :起始剂 /环氧丙烷/ 3 (2 ,4 ,6 三溴苯氧基 )环氧丙烷物质的量比为 0 18/ 3/ 1。当阻燃聚醚多元醇质量分数为 19%的国产 2 5 # 软质聚氨酯泡沫 ,氧指数达 2 7 1,其它物理特性也满足了GB/T 2 4 0 6 - 1993的要求。     

Comparison of RCM Precipitation Correction Methods for Hydrologic Simulation in Cold Region

It is a significant way to improve the accuracy of hydrologic simulation in the area having sparse observation sites by using the regional climate model precipitation driving hydrological model.As a result，a critical issue arises，which is how to correct the precipitation data coming from Regional Climate Model (RCM) based on the observation in the hydrology research in cold region.However，no systematic studies have been conducted to compare different precipitation correction methods and evaluate their impact on the hydrologic simulation in the cold region yet.Due to this，two kinds of mainstream regional climate model precipitation correction methods，Quantile Mapping (QM) and the Optimal Interpolation (OI)，have been compared and evaluated in Manas River basin between 2004 to 2009.The results show that both methods have their own advantages and disadvantages in statistical significance.The correction result of QM is good in low precipitation value and the average annual precipitation is more reasonable at spatial distribution.But when comes the high precipitation value，the result is not stable.Moreover，the correlation coefficient (R) and Root Mean Square Error(RMSE) doesn’t improve.Compared to R 0.37 and RMSE 2.80 mm/d，the modified R is 0.36 and RMSE is 2.70 mm/d;OI can improve R and RMSE significantly，one increases to 0.85 and the other reduces to1.46 mm/d after the correction.Despite that，OI also has its limitations.It gets more tiny precipitation relative to observation and the improvement of spatial distribution is not obvious.Using precipitation data before and after the correction to drive the hydrological models in a same set of model parameters.The results show that QM improves the simulation slightly，Nash-Sutcliffe efficiency coefficient (NSE) changes from 0.63 to 0.65 compared before，while OI is comparatively better，NSE increases to 0.71.This study is helpful to solve the problem of quality optimization in the preparation of hydrological simulation precipitation data and improve the precision of hydrologic simulation in cold region.     

Modes of inbound knowledge flows: are cooperation and outsourcing really complementary?

This study examines the relationship between breadths of two different modes of external knowledge: R&D outsourcing and cooperation. Building upon transaction costs literature and literature on research partner breadth and R&D outsourcing, we hypothesise an U-inverted relationship between outsourcing breadth and innovation performance and a complementary relationship between R&D outsourcing and R&D cooperation. The model is tested on a large sample based on CIS survey for Spain. The empirical analysis confirms the U-inverted relationship between outsourcing breadth and innovation and also reveals an interesting result: the complementary effect of R&D cooperation varies with the level of R&D outsourcing breadth and it is not confirmed for low and medium levels of R&D outsourcing breadth. The results have important implications for theory on the selection of different modes of inbound open innovation and for managers and their cooperation and outsourcing strategies.     

Electrochemistry and XPS study of an imidazoline as corrosion inhibitor of mild steel in an acidic environment

The effect of 2‐(2‐heptadec‐8‐enyl‐4,5‐dihydro‐imidazol‐1‐yl)‐ethylamine on the corrosion behavior of mild steel in aqueous hydrochloric acid was investigated using weight loss measurements, polarization scans, electrochemical impedance, and X‐ray photoelectron spectroscopy (XPS). The inhibition efficiencies and coverage degrees increased with the concentration of inhibitor but decreased proportionally with temperature. It appears that the steric hindrance of the aliphatic chain on the imidazoline ring adsorption may affect inhibitor efficiency. Polarization curves showed that the oleic imidazoline (OI) acted essentially as a mixed type inhibitor, in which the blocking of active sites occurred. As a result of film formation, impedance spectra revealed a considerable increase in the charge transfer resistance as indicated by the second capacitive loop. XPS depth profile analysis observed the presence of nitrogen and carbon species on the inhibitor film, which were associated to the OI.     

基于亚像素的乒乓球机器人本体位姿视觉测量

提出一种基于亚像素精度的特征点提取算法,结合PnP方法和正交迭代(OI)算法计算乒乓球机器人本体的位姿.根据摄像机成像时弥散斑的近似高斯分布,以亚像素精度精确求取色标块的边缘,利用边缘直线交点得到高精度的角点作为特征点.基于PnP算法利用上述特征点求取机器人位姿的初值,再通过OI算法进行优化,以保证其姿态矩阵的正交性.实验结果表明,该方法能快速准确地实现机器人本体的位姿测量.     

沥青阻燃性能的评价方法与性能研究

通过对沥青燃烧过程的分析,指出了现有的闪点、燃点评价方法在评价沥青持续燃烧能力上的不足,提出了氧指数评价方法.针对沥青的特点,通过试验分析,提出沥青氧指数试验的标准程序,并应用该方法比较了氧指数评价方法和闪点、燃点评价方法在评价沥青燃烧能力时的差异,验证了氧指数评价方法的合理性.通过试验研究了阻燃剂掺量对沥青路用性能指标和氧指数的影响,给出了推荐的阻燃剂掺量,以供工程应用.     

UNIFICATION AND APPLICATIONS OF MODERN OCEANIC／ATMOSPHERIC DATA ASSIMILATION ALGORITHMS

The key mathematics and applications of various modem atmospheric/oceanic data assimilation methods including Optimal Interpolation (OI), 4-dimensional variational approach (4D-Var) and filters were systematically reviewed and classified. Based on the data assimilation philosophy, i.e. , using model dynamics to extract the observational information, the common character of the problem, such as the probabilistic nature of the evolution of the atmospheric/oceanic system, noisy and irregularly spaced observations, and the advantages and disadvantages of these data assimilation algorithms, were discussed. In the filtering framework, all modern data assimilation algorithms were unified:OI/3D-Var is a stationary filter, 4D-Var is a linear (Kalman) filter and an ensemble of Kalman filters is able to construct a nonlinear filter.The nonlinear filter such as the Ensemble Kalman Filter (EN-KF), Ensemble Adjustment Kalman Filter (EAKF) and Ensemble Transformation Kalman Filter (ETKF) can, to some extent, account for the non-Gaussian information of the prior distribution from the model. The flow-dependent covariance estimated by an ensemble filter may be introduced to OI and 4D-Var to improve these traditional algorithms. In practice,the performance of algorithms may depend on the specific numerical model and the choice of algorithm may depend on the specific problem. However, the unification of algorithms allows us to establish a unified test system to evaluate these algorithms, which provides more insights into data assimilation philosophies and helps improve data assimilation techniques.