Joint Subcarriers and Power Allocation with Imperfect Spectrum Sensing for Cognitive D2D Wireless Multicast

( Yueyun Chen ),( Xiangyun Xu ),( Qun Lei ) 한국인터넷정보학회 2013 KSII Transactions on Internet and Information Syst Vol.7 No.7

Wireless multicast is considered as an effective transmission mode for the future mobile social contact services supported by Long Time Evolution (LTE). Though wireless multicast has an excellent resource efficiency, its performance suffers deterioration from the channel condition and wireless resource availability. Cognitive Radio (CR) and Device to Device (D2D) are two solutions to provide potential resource. However, resource allocation for cognitive wireless multicast based on D2D is still a great challenge for LTE social networks. In this paper, a joint sub-carriers and power allocation model based on D2D for general cognitive radio multicast (CR-D2D-MC) is proposed for Orthogonal Frequency-Division Multiplexing (OFDM) LTE systems. By opportunistically accessing the licensed spectrum, the maximized capacity for multiple cognitive multicast groups is achieved with the condition of the general scenario of imperfect spectrum sensing, the constrains of interference to primary users (PUs) and an upper-bound power of secondary users (SUs) acting as multicast source nodes. Furthermore, the fairness for multicast groups or unicast terminals is guaranteed by setting a lower-bound number of the subcarriers allocated to cognitive multicast groups. Lagrange duality algorithm is adopted to obtain the optimal solution to the proposed CR-D2D-MC model. The simulation results show that the proposed algorithm improves the performance of cognitive multicast groups and achieves a good balance between capacity and fairness.

Joint Resource Allocation for Cellular and D2D Multicast Based on Cognitive Radio

( Xiaolu Wu ),( Yueyun Chen ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.1

Device-to-device (D2D) communication is an excellent technology to improve the system capacity by sharing the spectrum resources of cellular networks. Multicast service is considered as an effective transmission mode for the future mobile social contact services. Therefore, multicast based on D2D technology can exactly improve the spectrum resource efficiency. How to apply D2D technology to support multicast service is a new issue. In this paper, a resource allocation scheme based on cognitive radio (CR) for D2D underlay multicast communication (CR-DUM) is proposed to improve system performance. In the cognitive cellular system, the D2D users as secondary users employing multicast service form a group and reuse the cellular resources to accomplish a multicast transmission. The proposed scheme includes two steps. First, a channel allocation rule aiming to reduce the interference from cellular networks to receivers in D2D multicast group is proposed. Next, to maximize the total system throughput under the condition of interference and noise impairment, we formulate an optimal transmission power allocation jointly for the cellular and D2D multicast communications. Based on the channel allocation, optimal power solution is in a closed form and achieved by searching from a finite set and the interference between cellular and D2D multicast communication is coordinated. The simulation results show that the proposed method can not only ensure the quality of services (QoS), but also improve the system throughput.

Swarm Intelligence-based Power Allocation and Relay Selection Algorithm for wireless cooperative network

( Yaxin Xing ),( Yueyun Chen ),( Chen Lv ),( Zheng Gong ),( Ling Xu ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.3

Cooperative communications can significantly improve the wireless transmission performance with the help of relay nodes. In cooperative communication networks, relay selection and power allocation are two key issues. In this paper, we propose a relay selection and power allocation scheme RS-PA-PSACO (Relay Selection-Power Allocation-Particle Swarm Ant Colony Optimization) based on PSACO (Particle Swarm Ant Colony Optimization) algorithm. This scheme can effectively reduce the computational complexity and select the optimal relay nodes. As one of the swarm intelligence algorithms, PSACO which combined both PSO (Particle Swarm Optimization) and ACO (Ant Colony Optimization) algorithms is effective to solve non-linear optimization problems through a fast global search at a low cost. The proposed RS-PA-PSACO algorithm can simultaneously obtain the optimal solutions of relay selection and power allocation to minimize the SER (Symbol Error Rate) with a fixed total power constraint both in AF (Amplify and Forward) and DF (Decode and Forward) modes. Simulation results show that the proposed scheme improves the system performance significantly both in reliability and power efficiency at a low complexity.

Evaluation and modeling of methyl green adsorption from aqueous solutions using loofah fibers

Xiaonan Tang,Yueyun Li,Runhai Chen,Fanlian Min,Juanjuan Yang,Yunhui Dong 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.1

Loofah fiber, an economical adsorbent material, was first developed for the methyl green (MG) removalfrom aqueous solutions. The loofah fibers were characterized by SEM, FTIR, N2-BET and the potentiometric titration. The pH, contact time and temperature were examined extensively. The adsorption of MG on loofah fiber increasedvery quickly in the pH range 3.0 to 7.0, remaining a high level at pH>7.0. The kinetics of adsorption of MG on theloofah fiber was proved to coincide with pseudo-second-order kinetic models (r2>0.99) very well. Langmuir isothermwas demonstrated to fit the experimental data better than Freundlich isotherm model. Monolayer adsorption capacityincreased with the increase of temperature. Thermodynamic constants were evaluated, and the results indicated thatMG adsorption onto loofah fiber was feasible, spontaneous and endothermic. The high removal efficiency of MG onloofah fiber suggested that the loofah fiber was suitable material in MG pollution cleanup.

Inequalities in Awareness and Attitude towards HPV and Its Vaccine between Local and Migrant Residents Who Participated in Cervical Cancer Screening in Shenzhen, China

Wei Lin,Yueyun Wang,Zhihua Liu,Bin Chen,Shixin Yuan,Bo Wu,Lin Gong 대한암학회 2020 Cancer Research and Treatment Vol.52 No.1

Purpose A cross-sectional survey was conducted to evaluate the differences on awareness and attitude towards human papillomavirus (HPV) and its vaccine between local and migrant residents who participated in cervical cancer screening in Shenzhen, China. Materials and Methods A total of 9,855 females sampled from healthcare institutions in 20 street blocks through the Cervical Cancer Prevention Network were surveyed in this study by a self-administered questionnaire. Multivariate logistic regression was conducted to explore the role of the hukou and resident status in the willingness to receive HPV vaccination. Results Local residents had a relatively higher awareness of HPV (62.0% vs. 35.6% vs. 29.9%, p < 0.001) and its vaccine (35.3% vs. 15.4% vs. 14.8%, p < 0.001), as well as a higher willingness to receive HPV vaccination (68.5% vs. 62.5% vs. 56.2%, p < 0.001) than non-permanent residents and floating population. Except for age, education level, marital status, monthly income, having daughter(s), and heard of HPV and its vaccine, the hukou and resident status significantly associated with the willingness to receive HPV vaccination (local residents vs. floating population: odds ratio, 1.216; 95% confidence interval, 1.057 to 1.398). None significant difference on the associated factors was found between local residents and internal migrants (p for interactions > 0.05). Conclusion Inequalities in awareness and attitude towards HPV and its vaccine existed between local and migrant residents in Shenzhen. The hukou and resident status did impact on the willingness to receive HPV vaccination, therefore, it is critical to implement effective health education campaigns on HPV and its vaccine among internal migrants.

Resource Allocation based on Hybrid Sharing Mode for Heterogeneous Services of Cognitive Radio OFDM Systems

( Qun Lei ),( Yueyun Chen ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.1

In cognitive radio networks (CRNs), hybrid overlay and underlay sharing transmission mode is an effective technique for improving the efficiency of radio spectrum. Unlike existing works in the literature, where only one secondary user (SU) uses overlay and underlay modes, the different transmission modes should be allocated to different SUs, according to their different quality of services (QoS), to achieve the maximal efficiency of radio spectrum. However, hybrid sharing mode allocation for heterogeneous services is still a challenge in CRNs. In this paper, we propose a new resource allocation method for hybrid sharing transmission mode of overlay and underlay (HySOU), to achieve more potential resources for SUs to access the spectrum without interfering with the primary users. We formulate the HySOU resource allocation as a mixed-integer programming problem to optimize the total system throughput, satisfying heterogeneous QoS. To decrease the algorithm complexity, we divide the problem into two sub-problems: subchannel allocation and power allocation. Cutset is used to achieve the optimal subchannel allocation, and the optimal power allocation is obtained by Lagrangian dual function decomposition and subgradient algorithm. Simulation results show that the proposed algorithm further improves spectrum utilization with a simultaneous fairness guarantee, and the achieved HySOU diversity gain is a satisfactory improvement.

Task Offloading Based on Edge Collaboration in MEC-Enabled IoV Networks

Deng, Tao Yu,Chen, Yueyun,Chen, Guang,Yang, Meijie,Du, Liping 한국통신학회 2023 Journal of communications and networks Vol.25 No.2

Benefiting from its abundant computing resourcesand low computing latency, mobile edge computing (MEC) isa promising approach for enhancing the computing capacity ofthe 5G Internet of vehicles (IoV). Because of the high mobility,handover is frequent and inevitable in IoV networks. In thispaper, we investigate an edge collaborative task offloading andsplitting strategy in MEC-enabled IoV networks, in which thetask is splitted on the edge and paralleling executed by eachpart of the task on several MEC servers when handover isoccured. Applications in IoV networks have flexible requirementson latency and energy consumption. To realize the tradeoffbetween latency and energy consumption, we formulate the taskoffloading and splitting as an optimization problem with the aimof minimizing the total cost of latency and energy consumptionby jointly optimizing the task splitting ratio and uplink transmitpower of vehicle terminal (VT). Because the proposed problemis non-smooth and non-convex, we divide the original probleminto two convex subproblems, and apply an alternate convexsearch (ACS) algorithm to obtain the optimized solution withlow computational complexity. Numerical simulation results showthat the proposed method can adjust the offloading strategyproperly according to task preference, and obtain a lower totalcost compared with the baseline algorithms.

Cyanide- and Phenoxo-Bridged Heterobimetallic Fe(III)-Mn(III) Coordination Polymer: Synthesis, Crystal Structures and Magnetic Properties

Daopeng Zhang,Lingqian Kong,Yueyun Li,Ping Wang,Xia Chen 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.9

Two two-dimensional cyanide- and phenoxo-bridged heterometallic M(II)-Mn(III) (M = Ni, Pd) coordination polymers {[Mn(saltmen)]4[Ni(CN)4]}(ClO4)2·CH3OH·H2O (1) and {[Mn(saltmen)]4[Pd(CN)4]}(ClO4)2· CH3CN·H2O (2) (saltmen2– = N,N'-(1,1,2,2-tetramethylethylene)bis(salicylideneaminato)dianion) have been obtained by using K2[M(CN)4] as building blocks and a salen-tpye Schiff-base manganese(III) compound as assembling segment. Single X-ray analysis reveals their isostrutural cyanide-bridged MMn4 pentanuclear cationic structure. The four Schiff base manganese units of the pentanuclear entity are self-complementary through the phenoxo oxygen atoms from the neighboring complex, therefore forming cyanide- and phenoxobridged 2D sheet-like structure. Investigation over magnetic susceptibilities reveals the overall ferromagnetic coupling between the adjacent Mn(III) ions bridged by the phenoxo oxygen atoms with J = 2.13 and 2.21 cm−1 for complexes 1 and 2, respectively.

Cervical Cancer Screening Rate and Willingness among Female Migrants in Shenzhen, China: Three-Year Changes in Citywide Surveys

Wei Lin,Bin Chen,Bo Wu,Shixin Yuan,Chuyan Zhong,Weikang Huang,Haiyan Hu,Zhihua Liu,Yueyun Wang 대한암학회 2021 Cancer Research and Treatment Vol.53 No.1

Purpose This study attempted to detect the changes of cervical cancer screening rate and willingness among female migrants, and the associated socio-demographic factors in Shenzhen city. Materials and Methods Two citywide surveys were conducted using a multistage random cluster sampling method in 2011 and 2014, respectively. Data on demographic characteristics, screening participation, and willingness to screen were collected. Logistic regression models were applied to detect possible associated socio-demographic characteristics, and their variations with survey years. Results In total, 12,017 female migrants were enrolled, with a mean age (standard deviation) of 36.73 (6.55) years. From 2011 to 2014, the screening rate increased (25.8% vs. 35.1%, p < 0.001), while the willingness to screen remained stable (82.2% vs. 82.8%, p=0.46). Overall, socio-demographic characteristics of female migrants, including age, marital status, education, monthly income, employment, and medical insurance, were found to be positively associated with screening participation. Similar impacts in relation to willingness were observed except for age. However, these associations varied with survey years, mainly in the contributions of education and monthly income to screening participation, as well as age, monthly income, and medical insurance to willingness of being screened. Conclusion Identifying changes of associated socio-demographic factors precisely is warranted of necessity, which provides novel clues to adjust targeted actions regularly in promoting cervical cancer screening participation among female migrants in Shenzhen.

Cyanide- and Phenoxo-Bridged Heterobimetallic Fe(III)-Mn(III) Coordination Polymer: Synthesis, Crystal Structures and Magnetic Properties

Zhang, Daopeng,Kong, Lingqian,Li, Yueyun,Wang, Ping,Chen, Xia Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.9

Two two-dimensional cyanide- and phenoxo-bridged heterometallic M(II)-Mn(III) (M = Ni, Pd) coordination polymers $\{[Mn(saltmen)]_4[Ni(CN)_4]\}(ClO_4)_2{\cdot}CH_3OH{\cdot}H_2O$ (1) and $\{[Mn(saltmen)]_4[Pd(CN)_4]\}(ClO_4)_2{\cdot}CH_3CN{\cdot}H_2O$ (2) ($saltmen^{2-}$ = N,N'-(1,1,2,2-tetramethylethylene)bis(salicylideneaminato)dianion) have been obtained by using $K_2[M(CN)_4]$ as building blocks and a salen-tpye Schiff-base manganese(III) compound as assembling segment. Single X-ray analysis reveals their isostrutural cyanide-bridged $MMn_4$ pentanuclear cationic structure. The four Schiff base manganese units of the pentanuclear entity are self-complementary through the phenoxo oxygen atoms from the neighboring complex, therefore forming cyanide- and phenoxo-bridged 2D sheet-like structure. Investigation over magnetic susceptibilities reveals the overall ferromagnetic coupling between the adjacent Mn(III) ions bridged by the phenoxo oxygen atoms with J = 2.13 and $2.21cm^{-1}$ for complexes 1 and 2, respectively.