针对非周期长码直接序列扩频(Non-Periodic Long Code Direct Sequence Spread Spectrum,NPLC-DSSS)信号扩频码盲估计的问题,在已知扩频周期,信息码码元宽度以及码速率的条件下,本文提出了一种基于相似度的伪码序列盲估计方法.该方法通...针对非周期长码直接序列扩频(Non-Periodic Long Code Direct Sequence Spread Spectrum,NPLC-DSSS)信号扩频码盲估计的问题,在已知扩频周期,信息码码元宽度以及码速率的条件下,本文提出了一种基于相似度的伪码序列盲估计方法.该方法通过构造信息码库,利用平均相似度对信息码进行同步,再利用特征值分解对扩频码序列进行估计.仿真实验表明,该算法较现有算法不仅抗噪声性能提高了1 dB,而且能够对信息码同步位置及伪码序列进行联合盲估计.展开更多
Memory-based collaborative recommender system (CRS) computes the similarity between users based on their declared ratings. However, not all ratings are of the same importance to the user. The set of ratings each user ...Memory-based collaborative recommender system (CRS) computes the similarity between users based on their declared ratings. However, not all ratings are of the same importance to the user. The set of ratings each user weights highly differs from user to user according to his mood and taste. This is usually reflected in the user’s rating scale. Accordingly, many efforts have been done to introduce weights to the similarity measures of CRSs. This paper proposes fuzzy weightings for the most common similarity measures for memory-based CRSs. Fuzzy weighting can be considered as a learning mechanism for capturing the preferences of users for ratings. Comparing with genetic algorithm learning, fuzzy weighting is fast, effective and does not require any more space. Moreover, fuzzy weightings based on the rating deviations from the user’s mean of ratings take into account the different rating scales of different users. The experimental results show that fuzzy weightings obviously improve the CRSs performance to a good extent.展开更多
为了降低有机发光器件(OLED)的功耗,同时又保证显示图像的质量,提出一种基于色调、饱和度和亮度(HSV,hue,saturation and value)色彩空间的OLED低功耗方法。通过整合亮度调节(VS)和饱和度调节(SS)降低显示图像的功耗,应用感兴趣区域(ROI...为了降低有机发光器件(OLED)的功耗,同时又保证显示图像的质量,提出一种基于色调、饱和度和亮度(HSV,hue,saturation and value)色彩空间的OLED低功耗方法。通过整合亮度调节(VS)和饱和度调节(SS)降低显示图像的功耗,应用感兴趣区域(ROI,region of interest)到图像边界逐级调节技术提升图像质量,采用平均结构相似度指数(MSSIM,mean structural similarity index)对原始输入图像和输出图像在亮度、对比度和结构相似性上进行比较以评价图像相似程度,达到保持较高图像质量的同时降低功耗的目的。实验结果表明,图像渐变级数level为15时,本文提出的亮度与饱和度整合调节(VSI)方法在保持图像的ROI具有80.31%的相似度的同时节省了57.93%的OLED功耗。展开更多
文摘针对非周期长码直接序列扩频(Non-Periodic Long Code Direct Sequence Spread Spectrum,NPLC-DSSS)信号扩频码盲估计的问题,在已知扩频周期,信息码码元宽度以及码速率的条件下,本文提出了一种基于相似度的伪码序列盲估计方法.该方法通过构造信息码库,利用平均相似度对信息码进行同步,再利用特征值分解对扩频码序列进行估计.仿真实验表明,该算法较现有算法不仅抗噪声性能提高了1 dB,而且能够对信息码同步位置及伪码序列进行联合盲估计.
文摘Memory-based collaborative recommender system (CRS) computes the similarity between users based on their declared ratings. However, not all ratings are of the same importance to the user. The set of ratings each user weights highly differs from user to user according to his mood and taste. This is usually reflected in the user’s rating scale. Accordingly, many efforts have been done to introduce weights to the similarity measures of CRSs. This paper proposes fuzzy weightings for the most common similarity measures for memory-based CRSs. Fuzzy weighting can be considered as a learning mechanism for capturing the preferences of users for ratings. Comparing with genetic algorithm learning, fuzzy weighting is fast, effective and does not require any more space. Moreover, fuzzy weightings based on the rating deviations from the user’s mean of ratings take into account the different rating scales of different users. The experimental results show that fuzzy weightings obviously improve the CRSs performance to a good extent.
文摘为了降低有机发光器件(OLED)的功耗,同时又保证显示图像的质量,提出一种基于色调、饱和度和亮度(HSV,hue,saturation and value)色彩空间的OLED低功耗方法。通过整合亮度调节(VS)和饱和度调节(SS)降低显示图像的功耗,应用感兴趣区域(ROI,region of interest)到图像边界逐级调节技术提升图像质量,采用平均结构相似度指数(MSSIM,mean structural similarity index)对原始输入图像和输出图像在亮度、对比度和结构相似性上进行比较以评价图像相似程度,达到保持较高图像质量的同时降低功耗的目的。实验结果表明,图像渐变级数level为15时,本文提出的亮度与饱和度整合调节(VSI)方法在保持图像的ROI具有80.31%的相似度的同时节省了57.93%的OLED功耗。
