目前基于协同过滤(collaborative filtering,CF)的Web服务推荐算法,使用的是Web服务的非功能性属性服务质量(quality of services,QoS),但是这类方法直接使用所有用户的QoS数据进行预测,并没有考虑用户的个性化偏好问题,导致在相似邻居...目前基于协同过滤(collaborative filtering,CF)的Web服务推荐算法,使用的是Web服务的非功能性属性服务质量(quality of services,QoS),但是这类方法直接使用所有用户的QoS数据进行预测,并没有考虑用户的个性化偏好问题,导致在相似邻居的选择阶段会得到不真实的相似度结果,进而影响QoS预测准确率。针对以上问题,提出了一种基于用户偏好的改进协同过滤Web服务推荐算法。该算法从QoS数据中提取出用户偏好数据,并将其作为近似邻居的选择标准,然后使用top-k算法确定目标用户及服务的相似邻居集合,最后联合相似邻居偏好比重,使用调和的皮尔逊相关系数算法(Pearson correlation coefficient,PCC)预测目标用户及服务的QoS值。实验结果表明,该算法能有效提高QoS预测准确率,从而提高了Web服务推荐质量。展开更多
Many tourists who travel to explore different cultures and cities worldwide aim to find the best tourist sites,accommodation,and food according to their interests.This objective makes it harder for tourists to decide ...Many tourists who travel to explore different cultures and cities worldwide aim to find the best tourist sites,accommodation,and food according to their interests.This objective makes it harder for tourists to decide and plan where to go and what to do.Aside from hiring a local guide,an option which is beyond most travelers’budgets,the majority of sojourners nowadays use mobile devices to search for or recommend interesting sites on the basis of user reviews.Therefore,this work utilizes the prevalent recommender systems and mobile app technologies to overcome this issue.Accordingly,this study proposes location-aware personalized traveler assistance(LAPTA),a system which integrates user preferences and the global positioning system(GPS)to generate personalized and location-aware recommendations.That integration will enable the enhanced recommendation of the developed scheme relative to those from the traditional recommender systems used in customer ratings.Specifically,LAPTA separates the data obtained from Google locations into name and category tags.After the data separation,the system fetches the keywords from the user’s input according to the user’s past research behavior.The proposed system uses the K-Nearest algorithm to match the name and category tags with the user’s input to generate personalized suggestions.The system also provides suggestions on the basis of nearby popular attractions using the Google point of interest feature to enhance system usability.The experimental results showed that LAPTA could provide more reliable and accurate recommendations compared to the reviewed recommendation applications.展开更多
针对Web数据库近似查询产生的多查询结果问题,提出了一种近似查询结果自动排序方法,该方法利用KL距离(Kullback-Leibler distance),PIR(probabilistic information retrieval)模型和查询历史(query history)来构建元组排序打分函数;打...针对Web数据库近似查询产生的多查询结果问题,提出了一种近似查询结果自动排序方法,该方法利用KL距离(Kullback-Leibler distance),PIR(probabilistic information retrieval)模型和查询历史(query history)来构建元组排序打分函数;打分函数根据结果元组中被查询指定的属性值对初始查询的满足度和未被查询指定的属性值与用户偏好的相关度来评估元组的排序分值.实验证明,提出的排序方法能够较好地满足用户需求和偏好,并具有较高执行效率.展开更多
Location privacy receives considerable attentions in emerging location based services.Most current practices however either ignore users＇ preferences or incompletely fulfill privacy preferences.In this paper,we propo...Location privacy receives considerable attentions in emerging location based services.Most current practices however either ignore users＇ preferences or incompletely fulfill privacy preferences.In this paper,we propose a privacy protection solution to allow users＇ preferences in the fundamental query of k nearest neighbors （kNN）.Particularly,users are permitted to choose privacy preferences by specifying minimum inferred region.Via Hilbert curve based transformation,the additional workload from users＇ preferences is alleviated.Furthermore,this transformation reduces time-expensive region queries in 2-D space to range the ones in 1-D space.Therefore,the time efficiency,as well as communication efficiency,is greatly improved due to clustering properties of Hilbert curve.Further,details of choosing anchor points are theoretically elaborated.The empirical studies demonstrate that our implementation delivers both flexibility for users＇ preferences and scalability for time and communication costs.展开更多
基金The authors would like to acknowledge the support of Prince Sultan University for paying the Article Processing Charges(APC)of this publication.
文摘Many tourists who travel to explore different cultures and cities worldwide aim to find the best tourist sites,accommodation,and food according to their interests.This objective makes it harder for tourists to decide and plan where to go and what to do.Aside from hiring a local guide,an option which is beyond most travelers’budgets,the majority of sojourners nowadays use mobile devices to search for or recommend interesting sites on the basis of user reviews.Therefore,this work utilizes the prevalent recommender systems and mobile app technologies to overcome this issue.Accordingly,this study proposes location-aware personalized traveler assistance(LAPTA),a system which integrates user preferences and the global positioning system(GPS)to generate personalized and location-aware recommendations.That integration will enable the enhanced recommendation of the developed scheme relative to those from the traditional recommender systems used in customer ratings.Specifically,LAPTA separates the data obtained from Google locations into name and category tags.After the data separation,the system fetches the keywords from the user’s input according to the user’s past research behavior.The proposed system uses the K-Nearest algorithm to match the name and category tags with the user’s input to generate personalized suggestions.The system also provides suggestions on the basis of nearby popular attractions using the Google point of interest feature to enhance system usability.The experimental results showed that LAPTA could provide more reliable and accurate recommendations compared to the reviewed recommendation applications.
文摘针对Web数据库近似查询产生的多查询结果问题,提出了一种近似查询结果自动排序方法,该方法利用KL距离(Kullback-Leibler distance),PIR(probabilistic information retrieval)模型和查询历史(query history)来构建元组排序打分函数;打分函数根据结果元组中被查询指定的属性值对初始查询的满足度和未被查询指定的属性值与用户偏好的相关度来评估元组的排序分值.实验证明,提出的排序方法能够较好地满足用户需求和偏好,并具有较高执行效率.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 61003057 and 60973023
文摘Location privacy receives considerable attentions in emerging location based services.Most current practices however either ignore users＇ preferences or incompletely fulfill privacy preferences.In this paper,we propose a privacy protection solution to allow users＇ preferences in the fundamental query of k nearest neighbors （kNN）.Particularly,users are permitted to choose privacy preferences by specifying minimum inferred region.Via Hilbert curve based transformation,the additional workload from users＇ preferences is alleviated.Furthermore,this transformation reduces time-expensive region queries in 2-D space to range the ones in 1-D space.Therefore,the time efficiency,as well as communication efficiency,is greatly improved due to clustering properties of Hilbert curve.Further,details of choosing anchor points are theoretically elaborated.The empirical studies demonstrate that our implementation delivers both flexibility for users＇ preferences and scalability for time and communication costs.
