Smart Recommendations for Renting Bikes in Bike-Sharing Systems

Vehicle-sharing systems—such as bike-, car-, or motorcycle-sharing systems—have become increasingly popular in big cities in recent years. On the one hand, they provide a cheaper and environmentally friendlier means of transportation than private cars, and on the other hand, they satisfy the individual mobility demands of citizens better than traditional public transport systems. One of their advantages in this regard is their availability, e.g., the possibility of taking (or leaving) a vehicle almost anywhere in a city. This availability obviously depends on different strategic and operational management decisions and policies, such as the dimension of the fleet or the (re)distribution of vehicles. Agglutination problems—where, due to usage patterns, available vehicles are concentrated in certain areas, whereas no vehicles are available in others—are quite common in such systems, and need to be dealt with. Research has been dedicated to this problem, specifying different techniques to reduce imbalanced situations. In this paper, we present and compare strategies for recommending stations to users who wish to rent or return bikes in station-based bike-sharing systems. Our first contribution is a novel recommendation strategy based on queuing theory that recommends stations based on their utility to the user in terms of lower distance and higher probability of finding a bike or slot. Then, we go one step further, defining a strategy that recommends stations by combining the utility of a particular user with the utility of the global system, measured in terms of the improvement in the distribution of bikes and slots with respect to the expected future demand, with the aim of implicitly avoiding or alleviating balancing problems. We present several experiments to evaluate our proposal with real data from the bike sharing system BiciMAD in Madrid.

ER rule classifier with an optimization operator recommendation

It is difficult for many classic classification methods to consider expert experience and classify small-sample datasets well. The evidential reasoning rule (ER rule) classifier can solve these problems. The ER rule has strong processing and comprehensive analysis abilities for diversified mixed information and can solve problems with expert experience effectively. Moreover, the initial parameters of the classifier constructed based on the ER rule can be set according to empirical knowledge instead of being trained by a large number of samples, which can help the classifier classify small-sample datasets well. However, the initial parameters of the ER rule classifier need to be optimized, and choosing the best optimization algorithm is still a challenge. Considering these problems, the ER rule classifier with an optimization operator recommendation is proposed in this paper. First, the initial ER rule classifier is constructed based on training samples and expert experience. Second, the adjustable parameters are optimized, in which the optimization operator recommendation strategy is applied to select the best algorithm by partial samples, and then experiments with full samples are carried out. Finally, a case study on a turbofan engine degradation simulation dataset is carried out, and the results indicate that the ER rule classifier has a higher classification accuracy than other classic classifiers, which demonstrates the capability and effectiveness of the proposed ER rule classifier with an optimization operator recommendation.

Personalized recommender system on whom to follow in Twitter

Recommender systems have been widely used in social networking sites. In this thesis, we propose a novel approach to recommend new followees to Twitter users by learning their historic friends-adding patterns. Based on a user’s past social graph and her interactions with other connected users, scores based on some of the commonly used recommendation strategies are calculated and passed into the learning machine along with the recently added list of followees of the user. Learning to rank algorithm then identifies the best combination of recommendation strategies the user adopted to add new followees in the past. Although users may not adopt any recommendation strategies explicitly, they may subconsciously or implicitly use some. If the actually added followees match with the ones suggested by the recommendation strategy, we consider users are implicitly using that strategy. The experiment using the real data collected from Twitter proves the effectiveness of the proposed approach.

Personalized recommender system on whom to follow in Twitter

Recommender systems have been widely used in social networking sites. In this thesis, we propose a novel approach to recommend new followees to Twitter users by learning their historic friends-adding patterns. Based on a user’s past social graph and her interactions with other connected users, scores based on some of the commonly used recommendation strategies are calculated and passed into the learning machine along with the recently added list of followees of the user. Learning to rank algorithm then identifies the best combination of recommendation strategies the user adopted to add new followees in the past. Although users may not adopt any recommendation strategies explicitly, they may subconsciously or implicitly use some. If the actually added followees match with the ones suggested by the recommendation strategy, we consider users are implicitly using that strategy. The experiment using the real data collected from Twitter proves the effectiveness of the proposed approach.

A New Citation Recommendation Strategy Based on Term Functions in Related Studies Section

Purpose Researchers frequently encounter the following problems when writing scientific articles: (1) Selecting appropriate citations to support the research idea is challenging. (2) The literature review is not conducted extensively, which leads to working on a research problem that others have well addressed. This study focuses on citation recommendation in the related studies section by applying the term function of a citation context, potentially improving the efficiency of writing a literature review. Design/methodology/approach We present nine term functions with three newly created and six identified from existing literature. Using these term functions as labels, we annotate 531 research papers in three topics to evaluate our proposed recommendation strategy. BM25 and Word2vec with VSM are implemented as the baseline models for the recommendation. Then the term function information is applied to enhance the performance. Findings The experiments show that the term function-based methods outperform the baseline methods regarding the recall, precision, and F1-score measurement, demonstrating that term functions are useful in identifying valuable citations. Research limitations The dataset is insufficient due to the complexity of annotating citation functions for paragraphs in the related studies section. More recent deep learning models should be performed to future validate the proposed approach. Practical implications The citation recommendation strategy can be helpful for valuable citation discovery, semantic scientific retrieval, and automatic literature review generation. Originality/value The proposed citation function-based citation recommendation can generate intuitive explanations of the results for users, improving the transparency, persuasiveness, and effectiveness of recommender systems.

Large-scale Prediction of Drug-Protein Interactions Based on Network Information

Background: The prediction of drug-protein interaction (DPI) plays an important role in drug discovery and re-positioning. Unfortunately, traditional experimental validation of DPIs is expensive and time-consuming. Therefore, it is necessary to develop in silico methods for the identification of potential DPIs. Method: In this work, the identification of DPIs was performed by the generated recommendation of the unexplored interaction of the drug-protein bipartite graph. Three kinds of recommenders were proposed to predict the potential DPIs. Results: The simulation results showed that the proposed models obtained good performance in cross validation and independent test. Conclusion: Our recommendation strategy based on collaborative filtering can effectively improve the DPI identification performance, especially for certain DPIs lacking chemical structure similarity or genomic sequence similarity.