Contract-Based Incentive Mechanisms for Device-to-Device Communications in Cellular Networks

Yanru Zhang,Lingyang Song,Saad, Walid,Dawy, Zaher,Zhu Han IEEE 2015 IEEE journal on selected areas in communications Vol.33 No.10

<P>Device-to-device (D2D) communication is viewed as one promising technology for boosting the capacity of wireless networks and the efficiency of resource management. D2D communication heavily depends on the participation of users in sharing contents. Thus, it is imperative to introduce new incentive mechanisms to motivate such user involvement. In this paper, a contract-theoretic approach is proposed to solve the problem of providing incentives for D2D communication in cellular networks. First, using the framework of contract theory, the users' preferences toward D2D communication are classified into a finite number of types, and the service trading between the base station and users is properly modeled. Next, necessary and sufficient conditions are derived to provide incentives for users' engagement in D2D communication. Finally, our analysis is extended to the case in which there is a continuum of users. Simulation results show that the contract can effectively incentivize users' participation, and increase capacity of the cellular network than the other mechanisms.</P>

A Social-Aware Framework for Efficient Information Dissemination in Wireless Ad Hoc Networks

Zhang, Yanru,Song, Lingyang,Jiang, Chunxiao,Tran, Nguyen H.,Dawy, Zaher,Han, Zhu IEEE 2017 IEEE communications magazine Vol.55 No.1

<P>In wireless ad hoc networks, each node participates in routing by forwarding data to other nodes without a pre-existing infrastructure. Particularly, with the wide adoption of smart devices, the concept of smartphone ad hoc networks (SPANs) has evolved to enable alternate means for information sharing. Using unlicensed frequency spectrum and short-range wireless technologies, a SPAN enables a new paradigm of applications and thus is seen as an attractive component in future wireless networks. In a SPAN, smartphones form local peer-to-peer networks to cooperate and share information efficiently. Recent studies have shown that if the users' social relations are considered while designing cooperation schemes and protocols in SPANs, the cooperation initialization and content dissemination can be notably improved to increase the overall network efficiency and communications reliability. In this article, we present a social-aware framework for optimizing SPANs by exploiting two layers: users' relationships in the online social network layer and users' offline connections and interactions in the physical wireless network layer. The online content popularity distribution is also studied as a result of the users' online interaction profiles. In the end, we integrate both online and offline layers, and discuss possible applications to further enhance the network performance.</P>

Social Network Aware Device-to-Device Communication in Wireless Networks

Yanru Zhang,Pan, Erte,Lingyang Song,Saad, Walid,Dawy, Zaher,Zhu Han IEEE 2015 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS Vol.14 No.1

<P>Device-to-device (D2D) communication is seen as a major technology to overcome the imminent wireless capacity crunch and to enable new application services. In this paper, a novel social-aware approach for optimizing D2D communication by exploiting two layers, namely the social network layer and the physical wireless network layer, is proposed. In particular, the physical layer D2D network is captured via the users' encounter histories. Subsequently, an approach, based on the so-called Indian Buffet Process, is proposed to model the distribution of contents in the users' online social networks. Given the social relations collected by the base station, a new algorithm for optimizing the traffic offloading process in D2D communications is developed. In addition, the Chernoff bound and approximated cumulative distribution function (cdf) of the offloaded traffic are derived and the validity of the bound and cdf is proven. Simulation results based on real traces demonstrate the effectiveness of our model and show that the proposed approach can offload the network's traffic successfully.</P>

Overlapping coalition formation games for emerging communication networks

Wang, Tianyu,Song, Lingyang,Han, Zhu,Saad, Walid IEEE 2016 IEEE network Vol.30 No.5

<P>Modern cellular networks are witnessing an unprecedented evolution from classical centralized and homogenous architectures into a mix of various technologies, in which the network devices are densely and randomly deployed in a decentralized and heterogenous architecture. This shift in network architecture requires network devices to become more autonomous and, potentially, cooperate with one another. Such cooperation can, for example, take place between interfering small access points that seek to coordinate their radio resource allocation, nearby single-antenna users that can cooperatively perform virtual MIMO communications, or even unlicensed users that wish to cooperatively sense the spectrum of licensed users. Such cooperative mechanisms involve the simultaneous sharing and distribution of resources among a number of overlapping cooperative groups or coalitions. In this article, a novel mathematical framework from cooperative games, dubbed overlapping coalition formation games (OCF games), is introduced to model and solve such cooperative scenarios. First, the concepts of OCF games are presented, and then several algorithmic aspects are studied for two main classes of OCF games. Subsequently, two example applications, interference management and cooperative spectrum sensing, are discussed in detail to show how the proposed models and algorithms can be used in future scenarios of wireless systems. Finally, we conclude by providing an overview on future directions and applications of OCF games.</P>

EFFECTS OF ULTRASONIC RADIATION INTENSITY ON THE OXIDATION OF SINGLE-WALLED CARBON NANOTUBES IN A MIXTURE OF SULFURIC AND NITRIC ACIDS

RUI HE,XIBO PEI,LANLAN PAN,LINGYANG TIAN,Feng Luo,LEI SUI,QIANBING WAN,JIAN WANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2013 NANO Vol.8 No.4

One of the most commonly used techniques for purification and eventual dispersion of single-wall carbon nanotubes (SWNTs) is oxidation using strong acid and ultrasonication. Literature review reveals that ultrasonication of varying radiation intensities have been used during the acid oxidation, but few have reported whether ultrasonication of different intensities would have different effects on the structure and properties of SWNTs and how the effects are. An investigation of the effects of ultrasonic radiation intensity on SWNTs during oxidation in a mixture of sulfuric and nitric acids was conducted. Ultrasonication using different intensities (50 W, 100 W, 200 W and 300 W) was used. The acid-treated SWNTs were characterized by scanning and transmission electron microscopy, Fourier transform infrared spectroscopy, zeta potential test Boehm titration test and Raman spectrum analysis. Data from these experiments showed that high intensities provided stronger oxidizing conditions than lower ones. As ultrasonic intensity increased, larger number of SWNTs were destroyed and consumed to produce carbonaceous impurities, and more defects appeared in the tube walls.

LncRNA-IMAT1 Promotes Invasion of Meningiomas by Suppressing KLF4/hsa-miR22-3p/Snai1 Pathway

Tao Zhang,Yu Ge,Daijun Wang,Qin Liu,Shuchen Sun,Lingyang Hua,Jiaojiao Deng,Shihai Luan,Haixia Cheng,Qing Xie,Ye Gong,Tao Zhang 한국분자세포생물학회 2022 Molecules and cells Vol.45 No.6

Malignant meningiomas often show invasive growth that makes complete tumor resection challenging, and they are more prone to recur after radical resection. Invasive meningioma associated transcript 1 (IMAT1) is a long noncoding RNA located on Homo sapiens chromosome 17 that was identified by our team based on absolute expression differences in invasive and non-invasive meningiomas. Our studies indicated that IMAT1 was highly expressed in invasive meningiomas compared with non-invasive meningiomas. In vitro studies showed that IMAT1 promoted meningioma cell invasion through the inactivation of the Krüppel-like factor 4 (KLF4)/hsa-miR22-3p/Snai1 pathway by acting as a sponge for hsa-miR22-3p, and IMAT1 knockdown effectively restored the tumor suppressive properties of KLF4 by preserving its tumor suppressor pathway. In vivo experiments confirmed that IMAT1 silencing could significantly inhibit the growth of subcutaneous tumors and prolong the survival period of tumor-bearing mice. Our findings demonstrated that the high expression of IMAT1 is the inherent reason for the loss of the tumor suppressive properties of KLF4 during meningioma progression. Therefore, we believe that IMAT1 may be a potential biological marker and treatment target for meningiomas.