Performance Analysis of IEEE 802.15.6 MAC Protocol in Beacon Mode with Superframes

( Changle Li ),( Xiaoyan Geng ),( Jingjing Yuan ),( Tingting Sun ) 한국인터넷정보학회 2013 KSII Transactions on Internet and Information Syst Vol.7 No.5

Wireless Body Area Networks (WBANs) are becoming increasingly important to solve the issue of health care. IEEE 802.15.6 is a wireless communication standard for WBANs, aiming to provide a real-time and continuous monitoring. In this paper, we present our development of a modified Markov Chain model and a backoff model, in which most features such as user priorities, contention windows, modulation and coding schemes (MCSs), and frozen states are taken into account. Then we calculate the normalized throughput and average access delay of IEEE 802.15.6 networks under saturation and ideal channel conditions. We make an evaluation of network performances by comparing with IEEE 802.15.4 and the results validate that IEEE 802.15.6 networks can provide high quality of service (QoS) for nodes with high priorities.

An Optical Graphene-silicon Resonator Phase Shifter Suitable for Universal Linear Circuits

Changling Liu,Jianping Wang,Hongyao Chen,Zizheng Li 한국광학회 2022 Current Optics and Photonics Vol.6 No.1

This paper describes the construction of a phase shifter with low loss and small volume. To construct it, we use the two graphene layers that are separated by a hexagonal boron nitride (hBN) and embedded in a silicon waveguide. The refractive index of the waveguide is adjusted by applying a bias voltage to the graphene sheet to create an optical phase shift. This waveguide is a compact device that only has a radius of 5 μm. It has a phase shift of 6π. In addition, the extinction ratio (ER) is 11.6 dB and the inser-tion loss (IL) is 0.031 dB. Due to its unique characteristics, this device has great potential in silicon onchip optical interconnection and all-optical multiple-input multiple-output processing.

Interface Properties of Epoxy and Polyurethane Mutually Sized Carbon Fiber Reinforced Composites

Shengxia Li,Changling Yang,Lili Yao,Bo Wu,Yonggen Lu 한국섬유공학회 2022 Fibers and polymers Vol.23 No.3

Anodized carbon fiber (OCF) is sized with epoxy sizing agent (EPS) and polyurethane sizing agent (PUS) toreinforce epoxy resin (EP) and polyurethane resin (PU) mutually. The dependence of interlaminar shear strength (ILSS) andfailure strain on the sizing agent and amount is investigated. The ILSS of the as-received OCF reinforced EP composite is59.5 MPa, while that of EPS sized OCF reinforced EP composite can be optimally increased to 66.7 MPa, and that of PUSsized OCF reinforced EP composite can be increased maximumly to 72.8 MPa. The ILSS of the as-received OCF reinforcedPU composite is 39.5 MPa, while that of PUS sized OCF reinforced PU composite can be optimally increased to 50.5 MPa,and that of EPS sized OCF reinforced PU composite can be increased maximumly to 63.9 MPa. The results show the EPS ismore suitable to size OCF for reinforcing PU while the PUS is more suitable to size OCF for reinforcing EP. Hence it isconcluded that the law of similarity and intermiscibility does not always work, rather the chemical reactions are moreimportant for strong interface formation. The sizing amount has a great influence on both the ILSS and failure strain.

An Efficient Downlink MAC Protocol for Multi-User MIMO WLANs

( Kui Liu ),( Changle Li ),( Chao Guo ),( Rui Chen ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.9

Multi-User Multiple-Input Multiple-Output (MU-MIMO) technology has recently attracted significant attention from academia and industry because of it is increasingly important role in improving networks` capacity and data rate. Moreover, MU-MIMO systems for the Fifth Generation (5G) have already been researched. High Quality of Service (QoS) and efficient operations at the Medium Access Control (MAC) layer have become key requirements. In this paper, we propose a downlink MU-MIMO MAC protocol based on adaptive Channel State Information (CSI) feedback (called MMM-A) for Wireless Local Area Networks (WLANs). A modified CSMA/CA mechanism using new frame formats is adopted in the proposed protocol. Specifically, the CSI is exchanged between stations (STAs) in an adaptive way, and a packet selection strategy which can guarantee a fairer QoS for scenarios with differentiated traffic is also included in the MMM-A protocol. We then derive the expressions of the throughput and access delay, and analyze the performance of the protocol. It is easy to find that the MMM-A protocol outperforms the commonly used protocols in terms of the saturated throughput and access delay through simulation and analysis results.

Phylogeny and Evolution of Calcineurin B‑Like (CBL) Gene Family in Grass and Functional Analyses of Rice CBLs

Min Jiang,Changling Zhao,Mingfu Zhao,Yongzhong Li,Guosong Wen 한국식물학회 2020 Journal of Plant Biology Vol.63 No.2

Calcium signals play critical functions in regulating diverse arrays of plant growth and development and mediating a variety of biotic and abiotic stress responses as a second messenger. Calcineurin B-like (CBL) proteins were involved with plantspecifc Ca2+signaling as calcium sensors. In this work, we retrieved 152 CBL gene members from 15 diferent grass species, surveyed their phylogenetic relationships and sequence features and also performed expression patterns and functional analyses of rice CBLs. Phylogenetic analysis indicated that grass CBLs fall into four diferent groups (Group A–D). Sequence analysis showed that CBL proteins harboring four conserved calcium-binding EF-hand have key amino acid residues Asp and Glu which had relatively high proportion in the average abundance. Molecular evolutionary analyses revealed that group A, B and C CBLs in their evolution process sufered the purifying selection, while group D CBLs were subjected to positive selection. Moreover, expression analyses showed signifcant divergent expression patterns of OsCBLs in various organs and under diferent hormones and abiotic stresses. Furthermore, tolerance analysis revealed that OsCBL3 and OsCBL8 overexpression transgenic rice seedlings improved salt tolerance and OsCBL5, OsCBL6 and OsCBL7 positively regulated drought stress. In general, the domain and base sequence of the CBL gene family is highly conserved in grasses. OsCBL genes had specifc gene expression profles and function in diferent stresses.

Gravity balance mechanism for a spatial robotic manipulator

Yanyan Chen,Yubin Liu,Changle Li,Gangfeng Liu,Yanhe Zhu,Jie Zhao,Hegao Cai 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.2

A gravity balance mechanism for spatial robotic manipulator is proposed. In this design, a parallelogram linkage mechanism, pulleys and springs are utilized to accomplish the balance. As a passive structure, it needs no motors or actuators, and safety is another great highlight of the mechanism. The balance mechanism can solve the balance problem of both planar 2-link mechanism and spatial 2-link mechanism (a roll-pitch-yaw-roll 2-link mechanism) by adding a rotational degree of freedom. This is a more simple and effective method to solve the balance problem of spatial linkage system, especially the linkage system of multi-degree of freedom joint. And the mechanism can be extended to solve a multilink balance problem.

MicroRNA-301b promotes cell proliferation and apoptosis resistance in triple-negative breast cancer by targeting CYLD

( Hongming Song ),( Dengfeng Li ),( Tianqi Wu ),( Dan Xie ),( Kaiyao Hua ),( Jiashu Hu ),( Xiaochong Deng ),( Changle Ji ),( Yijun Deng ),( Lin Fang ) 생화학분자생물학회(구 한국생화학분자생물학회) 2018 BMB Reports Vol.51 No.11

Aberrant expression of microRNAs (miRNAs) plays important roles in carcinogenesis and tumor progression. However, the expression and biological role of miR-301b in triple-negative breast cancer (TNBC) remains unclear. Here we aimed to evaluate the roles and mechanisms of miR-301b in TNBC cells. miR-301b expression was assessed in TNBC specimens and cell lines by quantitative Real-Time PCR (qRT-PCR). TNBC cells were transfected with miR-301b mimics, inhibitors or Cylindromatosis (CYLD) small interfering RNA (siRNA) using Lipofectamine 2000. The functional roles of miR-301b were determined by cell proliferation, colony formation, and apoptosis assays. Western blots and qRT-PCR were used to measure the expression of mRNAs and proteins in the cells. We found that miR-301b was upregulated in TNBC specimens and cell lines. Overexpression of miR-301b promoted cell proliferation in TNBC cells, while inhibited the apoptosis induced by 5-FU. CYLD was downregulated by miR-301b at both mRNA and protein levels in TNBC cells. Dual-luciferase report assay confirmed that miR-301b downregulated CYLD by direct interaction with the 3’-untranslated region(3’-UTR) of CYLD mRNA. NF-κB activation was mechanistically associated with miR-301b-mediated downregulation of CYLD. However, inhibition of miR-301b reversed all the effects of miR-301b. In conclusion, miR-301b plays an oncogenic role in TNBC possibly by downregulating CYLD and subsequently activating NF-κB p65, and this may provide a novel therapeutic approach for TNBC. [BMB Reports 2018; 51(11): 602-607]

Seismic vibration control of an innovative self-centering damper using confined SMA core

Canxing Qiu,Zhaohui Gong,Changle Peng,Han Li 국제구조공학회 2020 Smart Structures and Systems, An International Jou Vol.25 No.2

Using confined shape memory alloy (SMA) bar or plate, this study proposes an innovative self-centering damper. The damper is essentially properly machined SMA core, i.e., bar or plate, that encased in buckling-restrained device. To prove the design concept, cyclic loading tests were carried out. According to the test results, the damper exhibited desired flag-shape hysteretic behaviors upon both tension and compression actions, although asymmetric behavior is noted. Based on the experimental data, the hysteretic parameters that interested by seismic applications, such as the strength, stiffness, equivalent damping ratio and recentering capacity, are quantified. Processed in the Matlab/Simulink environment, a preliminary evaluation of the seismic control effect for this damper was conducted. The proposed damper was placed at the first story of a multi-story frame and then the original and controlled structures were subjected to earthquake excitations. The numerical outcome indicated the damper is effective in controlling seismic deformation demands. Besides, a companion SMA damper which represents a popular type in previous studies is also introduced in the analysis to further reveal the seismic control characteristics of the newly proposed damper. In current case, it was found that although the current SMA damper shows asymmetric tension-compression behavior, it successfully contributes comparable seismic control effect as those having symmetrical cyclic behavior. Additionally, the proposed damper even shows better global performance in controlling acceleration demands. Thus, this paper reduces the concern of using SMA dampers with asymmetric cyclic behavior to a certain degree.

VGLL4 interacts with STAT3 to function as a tumor suppressor in triple-negative breast cancer

Hongming Song,Qifeng Luo,Xiaochong Deng,Changle Ji,Dengfeng Li,Amik Munankarmy,Wei Jian,Junyong Zhao,Lin Fang 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

Triple-negative breast cancer (TNBC) is an aggressive malignancy with a poor prognosis, and there are no effective molecular-targeted drugs for TNBC patients in clinical practice. The JAK-STAT pathway is implicated in tumorigenesis and the progression of various cancers. In this study, the results demonstrated that VGLL4 is expressed at low levels in both TNBC specimens and cell lines and that VGLL4 expression is negatively correlated with Ki67 expression and tumor size in TNBC patients. VGLL4 knockdown can promote the growth of TNBC cells, while VGLL4 overexpression significantly suppresses the growth of TNBC cells in vitro. More importantly, VGLL4 significantly inhibits tumor progression in a nude mouse model. In addition, VGLL4 is a direct target of miR-454, and the upregulation of miR-454 decreases VGLL4 expression and promotes the cell growth of TNBC cells. Furthermore, we also demonstrated that VGLL4 interacts with STAT3, the core component of the JAK-STAT pathway, leading to the inactivation of STAT3 and the inhibition of STAT3 downstream transcription. Collectively, these findings indicate that VGLL4 expression is negatively associated with poor prognosis in TNBC patients. High expression of miR-454 may be one of the causes of the downregulation of VGLL4 in TNBC, and VGLL4 acts as a tumor suppressor in TNBC by interacting with STAT3 and subsequently suppresses the STAT3 signaling axis, providing potential biomarkers and therapeutic approaches for this fatal disease.

Performance Analysis of IEEE 802.15.4e Time Slotted Channel Hopping for Low-Rate Wireless Networks

( Shuguang Chen ),( Tingting Sun ),( Jingjing Yuan ),( Xiaoyan Geng ),( Changle Li ),( Sana Ullah ),( Mohammed Abdullah Alnuem ) 한국인터넷정보학회 2013 KSII Transactions on Internet and Information Syst Vol.7 No.1

The release of IEEE 802.15.4e specification significantly develops IEEE 802.15.4. The most inspiring improvement is the enhancement for medium access control (MAC) sublayer. To study the performance of IEEE 802.15.4e MAC, in this paper we first present an overview of IEEE 802.15.4e and introduce three MAC mechanisms in IEEE 802.15.4e. And the major concern here is the Time Slotted Channel Hopping (TSCH) mode that provides deterministic access and increases network capacity. Then a detailed analytical Markov chain model for TSCH carrier sense multiple access with collision avoidance (CSMA-CA) is presented. Expressions which cover most of the crucial issues in performance analysis such as the packet loss rate, energy consumption, normalized throughput, and average access delay are presented. Finally the performance evaluation for the TSCH mode is given and we make a comprehensive comparison with unslotted CSMA-CA in non-beacon enabled mode of IEEE 802.15.4. It can validate IEEE 802.15.4e network can provide low energy consumption, deterministic access and increase network capacity.