Social Network Analysis

Transactions of the Institute of British Geographers

Matrix Factorization Techniques for Recommender Systems

本文对国际科学计量学杂志《Ｓｃｉｅｎｔｏｍｅｔｒｉｃｓ》１９７９－１９９１年的研究论文内容、栏目、作者及国别和编委及国别作了计量分析，揭示出科学计量学研究的重点、活动的中心及发展趋势，说明了学科带头人在发展科学计量学这门新兴学科中的作用。

国际刊物《Scientometrics》文献计量研究

Migrating computational intensive tasks from mobile devices to more resourceful cloud servers is a promising technique to increase the computational capacity of mobile devices while saving their battery energy. In this paper, we consider an MIMO multicell system where multiple mobile users (MUs) ask for computation offloading to a common cloud server. We formulate the offloading problem as the joint optimization of the radio resources—the transmit precoding matrices of the MUs—and the computational resources—the CPU cycles/second assigned by the cloud to each MU—in order to minimize the overall users’ energy consumption, while meeting latency constraints. The resulting optimization problem is nonconvex (in the objective function and constraints). Nevertheless, in the single-user case, we are able to compute the global optimal solution in closed form. In the more challenging multiuser scenario, we propose an iterative algorithm, based on a novel successive convex approximation technique, converging to a local optimal solution of the original nonconvex problem. We then show that the proposed algorithmic framework naturally leads to a distributed and parallel implementation across the radio access points, requiring only a limited coordination/signaling with the cloud. Numerical results show that the proposed schemes outperform disjoint optimization algorithms.

Joint Optimization of Radio and Computational Resources for Multicell Mobile-Edge Computing

This paper addresses a well-documented open problem on the tracking target of the multiple unmanned aerial vehicles (UAVs) subject to the inconsistent of attitude and position in the process of flight. The main contribution is to study a UAV cooperative formation control of tracking a moving target and analyze the flight stability of the designed controller when only knowing the UAV local information. The path planning of a single UAV and multiple UAV cooperative formation tracking of a moving target is studied. First, the feedback control is used to ensure heading convergence for the path planning of a single UAV. Furthermore, we use a variable airspeed controller to achieve the desired angular spacing and build the information architecture using graph theory for the UAV formation tracking of moving targets. The communication data management module at the cloud stores and transmits to UAV by the ground station. The ground command can maintain a UAV control center which gets access to the cloud for the UAV activity management. In addition, the design of a distributed control law is achieved based on the type of information construction between UAVs. The simulation results show that the designed controller is robust for tracking moving targets and achieves good flight-stability when tracking such targets.

Design and Information Architectures for an Unmanned Aerial Vehicle Cooperative Formation Tracking Controller

Cross-domain recommender systems adopt multiple methods to build relations
 from source domain to target domain in order to alleviate problems of cold
 start and sparsity, and improve the performance of recommendations. The
 majority of traditional methods tend to associate users and items, which
 neglected the strong influence of friend relation on the recommendation. In
 this paper, we propose a cross-domain item recommendation model called CRUS
 based on user similarity, which firstly introduces the trust relation among
 friends into cross-domain recommendation. Despite friends usually tend to
 have similar interests in some domains, they share differences either.
 Considering this, we define all the similar users with the target user as
 Similar Friends. By modifying the transfer matrix in the random walk, friends
 sharing similar interests are highlighted. Extensive experiments on Yelp data
 set show CRUS outperforms the baseline methods on MAE and RMSE.

/pdf/cross-domain-item-recommendation-based-on-user-similarity-4owbh3l8r0.pdf

Cross-domain item recommendation based on user similarity

With the increasing demands for high-quality health-care services, medical cyber-physical systems over wireless body sensor networks have emerged as a promising solution for vital life signals monitoring. These systems require the communication protocols to be both reliable and real-time in data transmissions. IEEE 802.15.4 can be regarded as the canonical protocols in this area owing to its low-power and low-cost features. However, it falls short of reliability and timeliness guarantees. To address this issue, we propose an adaptive MAC protocol based on IEEE 802.15.4, namely Ada-MAC. The proposed protocol combines schedule-based on time-triggered protocol and contention-based CSMA/CA mechanism. It can not only enable dynamic Guaranteed Time Slots allocation but also provide differentiated services for different nodes according to their data types. The proposed protocol is implemented on the OMNeT++ platform. Extensive simulations are conducted to evaluate the performance of Ada-MAC in comparison with the traditional IEEE 802.15.4 MAC. The results show the superiority of the proposed protocol in terms of reliability and timeliness.

An adaptive MAC protocol for real-time and reliable communications in medical cyber-physical systems

Advisor–advisee relationship is important in academic networks due to its universality and necessity. Despite the increasing desire to analyze the career of newcomers, however, the outcomes of different collaboration patterns between advisors and advisees remain unknown. The purpose of this paper is to find out the correlation between advisors’ academic characteristics and advisees’ academic performance in Computer Science. Employing both quantitative and qualitative analysis, we find that with the increase of advisors’ academic age, advisees’ performance experiences an initial growth, follows a sustaining stage, and finally ends up with a declining trend. We also discover the phenomenon that accomplished advisors can bring up skilled advisees. We explore the conclusion from two aspects: (1) Advisees mentored by advisors with high academic level have better academic performance than the rest; (2) Advisors with high academic level can raise their advisees’ h-index ranking. This work provides new insights on promoting our understanding of the relationship between advisors’ academic characteristics and advisees’ performance, as well as on advisor choosing.

Understanding the advisor–advisee relationship via scholarly data analysis

Editors play a critical role in the peer review system. How do editorial behaviors affect the performance of peer review? No quantitative model to date allows us to measure the influence of editorial behaviors on different peer review stages such as, manuscript distribution and final decision making. Here, we propose an agent-based model in which the process of peer review is guided mainly by the social interactions among three kinds of agents representing authors, editors and reviewers respectively. We apply this model to analyze a number of editorial behaviors such as decision strategy, number of reviewers and editorial bias on peer review. We find out that peer review outcomes are significantly sensitive to different editorial behaviors. With a small fraction (10 %) of biased editors, the quality of accepted papers declines 11 %, which indicates that effects of editorial biased behavior is worse than that of biased reviewers (7 %). While several peer review models exist, this is the first account for the study of editorial behaviors that is validated on the basis of simulation analysis.

/pdf/editorial-behaviors-in-peer-review-58fcrjkk63.pdf

Xiangjie Kong

Papers

Design and Information Architectures for an Unmanned Aerial Vehicle Cooperative Formation Tracking Controller

Cross-domain item recommendation based on user similarity

An adaptive MAC protocol for real-time and reliable communications in medical cyber-physical systems

Understanding the advisor–advisee relationship via scholarly data analysis

Editorial behaviors in peer review