Content-based filtering E-commerce recommender system was discussed fully in this paper. Users＇ unique features can be explored by means of vector space model firstly. Then based on the qualitative value of products ...Content-based filtering E-commerce recommender system was discussed fully in this paper. Users＇ unique features can be explored by means of vector space model firstly. Then based on the qualitative value of products informa tion, the recommender lists were obtained. Since the system can adapt to the users＇ feedback automatically, its performance were enhanced comprehensively. Finally the evaluation of the system and the experimental results were presented.展开更多
With the flooding of pornographic information on the Internet, how to keep people away from that offensive information is becoming one of the most important research areas in network information security. Some applica...With the flooding of pornographic information on the Internet, how to keep people away from that offensive information is becoming one of the most important research areas in network information security. Some applications which can block or filter such information are used. Approaches in those systems can be roughly classified into two kinds: metadata based and content based. With the development of distributed technologies, content based filtering technologies will play a more and more important role in filtering systems. Keyword matching is a content based method used widely in harmful text filtering. Experiments to evaluate the recall and precision of the method showed that the precision of the method is not satisfactory, though the recall of the method is rather high. According to the results, a new pornographic text filtering model based on reconfirming is put forward. Experiments showed that the model is practical, has less loss of recall than the single keyword matching method, and has higher precision.展开更多
根据某水电站及其周围移民场地布设的全球卫星导航系统(Global Navigation Satellite System Observations,GNSS)控制网的观测数据,利用GNSS观测值建立水电站及其周围地区的电离层垂直方向总电子含量(Vertical Total Electron Content,V...根据某水电站及其周围移民场地布设的全球卫星导航系统(Global Navigation Satellite System Observations,GNSS)控制网的观测数据,利用GNSS观测值建立水电站及其周围地区的电离层垂直方向总电子含量(Vertical Total Electron Content,VTEC)模型,对该地区的电离层VTEC变化规律进行了研究。实验研究表明,Butterworth滤波方法平滑VTEC的效果优于滑动平均滤波方法的平滑效果。采用Butterworth滤波方法平滑电离层VTEC的时间序列,分析水电站及其周边区域的电离层VTEC的周日变化规律,可进一步揭示该地区的电离层变化规律。展开更多
基金Supported bythe Hunan Teaching Reformand Re-search Project of Colleges and Universities (2003-B72) the HunanBoard of Review on Philosophic and Social Scientific Pay-off Project(0406035) the Hunan Soft Science Research Project(04ZH6005)
文摘Content-based filtering E-commerce recommender system was discussed fully in this paper. Users＇ unique features can be explored by means of vector space model firstly. Then based on the qualitative value of products informa tion, the recommender lists were obtained. Since the system can adapt to the users＇ feedback automatically, its performance were enhanced comprehensively. Finally the evaluation of the system and the experimental results were presented.
文摘With the flooding of pornographic information on the Internet, how to keep people away from that offensive information is becoming one of the most important research areas in network information security. Some applications which can block or filter such information are used. Approaches in those systems can be roughly classified into two kinds: metadata based and content based. With the development of distributed technologies, content based filtering technologies will play a more and more important role in filtering systems. Keyword matching is a content based method used widely in harmful text filtering. Experiments to evaluate the recall and precision of the method showed that the precision of the method is not satisfactory, though the recall of the method is rather high. According to the results, a new pornographic text filtering model based on reconfirming is put forward. Experiments showed that the model is practical, has less loss of recall than the single keyword matching method, and has higher precision.
文摘根据某水电站及其周围移民场地布设的全球卫星导航系统(Global Navigation Satellite System Observations,GNSS)控制网的观测数据,利用GNSS观测值建立水电站及其周围地区的电离层垂直方向总电子含量(Vertical Total Electron Content,VTEC)模型,对该地区的电离层VTEC变化规律进行了研究。实验研究表明,Butterworth滤波方法平滑VTEC的效果优于滑动平均滤波方法的平滑效果。采用Butterworth滤波方法平滑电离层VTEC的时间序列,分析水电站及其周边区域的电离层VTEC的周日变化规律,可进一步揭示该地区的电离层变化规律。
