Turbo-Based DNW Algorithm for Compressed Video in VLC Domain

In order to improve the robustness of the differential number watermarking (DNW) algorithm proposed by us before, we proposed turbo-based DNW (TDNW) in which the turbo code was employed in the DNW algorithm. The turbo code was used to encode the message prior to watermark embedding and decode the watermark posterior to watermark detection. From the analysis and experiments, the following conclusion could be drawn. The T-DNW algorithm has little higher computational complexity than DNW. And both algorithms have the same performance ;,n terms of watermark visual quality impact. Furthermore, the TDNW algorithm is much more robust against some common attack than DNW. Ahhough the TDNW algorithm sacrifices a half payload, we think the achievements are encouraging.     

红树林内生真菌Paecilomyces sp．（treel—7）蒽醌类代谢产物研究

红树林内生真菌Paecilomyces sp．（treel-7）采自红树植物秋茄树皮,在实验室150L规模下静置培养．反复进行硅胶,Sephadex LH-20柱层析．通过1D,2DNMR和EI—MS等手段鉴定5个蒽醌类化合物和2个甾体类代谢产物的结构．通过MTT法测试5个蒽醌类化合物有抑制鼻咽癌细胞（KB,KBv）的活性,结果显示葸醌类化合物1-5对鼻咽癌细胞有不同程度的抑制活性．     

木材蠕变特性常数化研究方法探讨

为了探讨确定木材蠕变特性的常数的方法，用应变测试方法代替相关文献的挠度测试方法对试件进行试验，结果获得木材稳定蠕变阶段内的木材蠕变曲线，测取3个常数:J0, η0、∑^Ji即足以说明材料的蠕变特性。简化了实验，使木材蠕变特性的工程评价变得十分便捷。     

H．264视频编码标准中新型特性的研究

介绍了H．264的新特点，详细研究了H．264在预测、变换、熵编码以及滤波等方面的改进技术。     

HS-SPME/GC-MS/GC-O对镇江香醋特征香气成分的确定

采用顶空固相微萃取提取了镇江香醋的挥发性成分,用气相色谱-质谱联用技术结合气相色谱-嗅觉测量法以及化合物的保留指数,鉴定了镇江香醋的主要香气成分;同时利用气相色谱-嗅觉测量技术,采用探测频率和探测强度相结合的办法,初步确定了乙酸、3-甲基丁酸、乙酸乙酯、乙酸-3-甲基-丁酯、乙酸苯乙酯、苯乙醇、2,3-丁二酮、二氢-5-戊基-2(3H)-呋喃酮、2-甲基丙醛、3-甲基丁醛、糠醛、苯甲醛、三甲基恶唑、2,3-二甲基吡嗪、三甲基吡嗪、四甲基吡嗪16种化合物为镇江香醋的特征香味物质.     

基于迁移学习的双层单目标优化算法

提出一种基于迁移学习的双层优化算法(BLOA-TF)来求解双层单目标优化问题(BLSOPs),该算法融合了机器学习领域的迁移学习思想．首先,通过聚类算法挑选出有代表的个体进行下层优化,将获得的下层优化信息使用归档集记录;然后,将归档集记录的下层优化信息迁移给其他相近未经下层优化的个体,以此加速整个优化过程,并有效减少计算开销;最后,将所提出的算法与通常基于嵌套的双层优化算法在12个标准测试问题上进行比较,实验结果证明了所提算法用于处理双层单目标优化问题的有效性．     

Predicted methylation landscape of all CpG islands on the human genome

CpG island methylation plays important role in various biological processes. To investigate methylation landscape of all CpG islands on the human genome, we develop a model for predicting the CpG island methylation status. This model outperforms other existing methods. We apply the model on the whole human genome and predict the landscape of DNA methylation of all CpG islands. Based on the methylation profile, we find that about 31% of CpG islands are methylation-prone and CpG islands located in promoter regions are seldom methylated. There is no significant difference in the CpG island methylation level between R and G bands among the chromosomes. The occupancy of RNA polymerase II is significantly higher in methylation-resistant promoter CpG islands, indicating that genes with such promoter CpG islands tend to be more active.     

分光光度法对偏最小二乘法和主成分分析计算结果影响的研究

以两组分混合物模型体系为例初步研究了多组分体系光谱重叠程度、校正集样品数、测量波长数、组分浓度之比及随机误差等因素对偏最小二乘法和主成分分析计算结果的影响,还以食用色素二组分体系的光谱数据为例说明如何利用混合物模型体系来选择其测量参数并预报测定误差     

Fast and accurate measurement of diffusion coefficient by Taylor’s dispersion analysis

This investigation aimed at improving the performance of Taylor's dispersion analysis for the fast and accurate measurement of diffusion coefficient of a minute solute in various solvents. The investigation was carried out on a capillary electrophoresis instrument by monitoring the UV absorption peak of a solute pulse and calculating the diffusion coefficient by peak efficiency. With L-phenylalanine as a main testing solute, some key factors were afterward disclosed including especially the capillary size, carrier flow velocity, injection volume and capillary conditioning. Peak tailing, large volume of sample injection and slow migration were found to underestimate the diffusion coefficient while very fast migration and high sample concentration caused overestimation. At a moderate flow velocity of 0.1―1 cm/s with a capillary of 72.44 μm I.D.×60 cm (50 cm effective) maintained at 25℃, the diffusion coefficient of aqueous L-phenylalanine was determined, giving a value of 7.02×10-6 cm2/s with error＜2% and relative standard deviation＜0.2% (n=3). The method was shown to be applicable to the measurement of various samples such as aqueous phenylalanine, acetone, phenol, toluene and benzene, and nonaqueous benzene (in ethanol or 1-butanol).     

基于行车声音端点检测的交通量统计

基于传统特征的行车声音端点检测法存在重叠有车段识别率低、双门限阈值较难确定的问题,针对这两个问题,探索性地将梅尔频率倒谱系数(Mel frequency cepstral coefficients,MFCC)倒谱距离特征和短时能量特征进行了融合并应用于交通量检测。首先选取了周围环境较为安静的一个双车道路段,并采集了该路段上包含重叠有车段的行车声音;其次提取了行车声音的短时能量特征和MFCC倒谱距离特征,并对它们在端点检测中的优劣进行了分析对比;再次提出了一种融合短时能量特征和MFCC倒谱距离特征的新特征,并基于新特征将传统的双门限判决思路改进成了单门限判决思路;最后利用新特征对有车段进行端点检测并统计交通量。实验结果表明:基于融合特征的端点检测方法能有效解决重叠有车段识别率低和双门限阈值较难确定的问题。