Modulation Recognition of BPSK/QPSK Signals based on Features in the Graph Domain

Li Yang,Guobing Hu,Xiaoyang Xu,Pinjiao Zhao 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.11

The performance of existing recognition algorithms for binary phase shift keying (BPSK) and quadrature phase shift keying (QPSK) signals degrade under conditions of low signal-to-noise ratios (SNR). Hence, a novel recognition algorithm based on features in the graph domain is proposed in this study. First, the power spectrum of the squared candidate signal is truncated by a rectangular window. Thereafter, the graph representation of the truncated spectrum is obtained via normalization, quantization, and edge construction. Based on the analysis of the connectivity difference of the graphs under different hypotheses, the sum of degree (SD) of the graphs is utilized as a discriminate feature to classify BPSK and QPSK signals. Moreover, we prove that the SD is a Schur-concave function with respect to the probability vector of the vertices (PVV). Extensive simulations confirm the effectiveness of the proposed algorithm, and its superiority to the listed model-driven-based (MDB) algorithms in terms of recognition performance under low SNRs and computational complexity. As it is confirmed that the proposed method reduces the computational complexity of existing graph-based algorithms, it can be applied in modulation recognition of radar or communication signals in real-time processing, and does not require any prior knowledge about the training sets, channel coefficients, or noise power.

A bis(2-oxoindolin-3-ylidene)-benzodifuran-dione containing copolymer for high-mobility ambipolar transistors

Zhang, Guobing,Li, Peng,Tang, Longxiang,Ma, Jingxuan,Wang, Xianghua,Lu, Hongbo,Kang, Boseok,Cho, Kilwon,Qiu, Longzhen The Royal Society of Chemistry 2014 Chemical communications Vol.50 No.24

<P>A bis(2-oxoindolin-3-ylidene)-benzodifuran-dione (BIBDF)-based low band gap polymer (PBIBDF-BT), containing a solubilizing alkyl chain bithiophene unit as a donor, has been synthesized. The polymer with a low-lying LUMO/HOMO energy level (−4.03/−5.55 eV) exhibits efficient ambipolar charge transport. The electron and hole mobilities are as high as 1.08 and 0.30 cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP>, respectively.</P> <P>Graphic Abstract</P><P>The PBIBDF-BT polymer exhibits high ambipolar charge transport with electron and hole mobilities as high as 1.08 and 0.30 cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP>, respectively. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c3cc48695h'> </P>

Analytical Approximation Algorithm for the Inverse of the Power of the Incomplete Gamma Function Based on Extreme Value Theory

( Shanshan Wu ),( Guobing Hu ),( Li Yang ),( Bin Gu ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.12

This study proposes an analytical approximation algorithm based on extreme value theory (EVT) for the inverse of the power of the incomplete Gamma function. First, the Gumbel function is used to approximate the power of the incomplete Gamma function, and the corresponding inverse problem is transformed into the inversion of an exponential function. Then, using the tail equivalence theorem, the normalized coefficient of the general Weibull distribution function is employed to replace the normalized coefficient of the random variable following a Gamma distribution, and the approximate closed form solution is obtained. The effects of equation parameters on the algorithm performance are evaluated through simulation analysis under various conditions, and the performance of this algorithm is compared to those of the Newton iterative algorithm and other existing approximate analytical algorithms. The proposed algorithm exhibits good approximation performance under appropriate parameter settings. Finally, the performance of this method is evaluated by calculating the thresholds of space-time block coding and space-frequency block coding pattern recognition in multiple-input and multiple-output orthogonal frequency division multiplexing. The analytical approximation method can be applied to other related situations involving the maximum statistics of independent and identically distributed random variables following Gamma distributions.

A New Dynamic Transmission-Mode Selection Scheme for AMC/HARQ-Based Wireless Networks

( Xiaohui Ma ),( Guobing Li ),( Guomei Zhang ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.11

In this paper, we study the cross-layer design for the AMC/HARQ-based wireless networks, and propose a new dynamic transmission-mode selection scheme to improve system spectrum efficiency. In the proposed scheme, dynamic thresholds for transmission-mode selection in each packet transmission and retransmission are jointly designed under the constraint of the overall packet error rate. Comparing with the existing schemes, the proposed scheme is inclined to apply higher modulation order at the first several (re)transmissions, which corresponds to higher-rate transmission modes thus higher average system spectrum efficiency. We also extend the cross-layer design to MIMO (Multi-input Multi-output) communication scenarios. Numerical results show that the proposed new dynamic transmission-mode selection scheme generally achieves higher average spectrum efficiency than the conventional and existing cross-layer design.

Portal pressure gradient and serum albumin: A simple combined parameter associated with the appearance of ascites in decompensated cirrhosis treated with transjugular intrahepatic portosystemic shunt

Dongmei Zhao,Guobing Zhang,Mingquan Wang,Chaoxue Zhang,Jiabin Li 대한간학회 2019 Clinical and Molecular Hepatology(대한간학회지) Vol.25 No.2

Background/Aims: In recent years, greater assessment accuracy after transjugular intrahepatic portosystemic shunt (TIPS) to ascertain prognosis has become important in decompensated cirrhosis due to portal hypertension. The aim of this study was to assess the ratio of the portal pressure gradient (PPG) pre-TIPS (pre-PPG) to albumin (PPA), which influence ascites formation in cirrhotic patients in the 6-months after TIPS placement, and is a metric introduced in our study. Methods: This was a retrospective cohort study of 58 patients with decompensated cirrhosis admitted to an academic hospital for the purpose of TIPS placement. We collected the following data: demographics, laboratory measures, and PPG during the TIPS procedure. Then we analyzed the association between the above data and ascites formation post- TIPS in cirrhosis patients. Results: Twenty-two patients with ascites and 28 without ascites were evaluated. Univariate and binary logistic regression analysis were adjusted for the following variables: to determine prognosis; Child-Pugh scores, lymphocyte count, platelet count, hemoglobin level, albumin level and pre-PPG or PPA. The outcome showed that PPA was better than pre-PPG and albumin for predicting ascites according to area under receiver operating characteristic curves and a statistical model that also showed PPA’s influence 6-months post-TIPS. Conclusions: The combined measurement of pre-PPG and albumin, defined as PPA, may provide a better way to predict post-TIPS ascites in decompensated cirrhosis, which underlines the need for a large clinical trial in the future.

Interference Management by Vertical Beam Control Combined with Coordinated Pilot Assignment and Power Allocation in 3D Massive MIMO Systems

( Guomei Zhang ),( Bing Wang ),( Guobing Li ),( Fei Xiang ),( Gangming Lv ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.8

In order to accommodate huge number of antennas in a limited antenna size, a large scale antenna array is expected to have a three dimensional (3D) array structure. By using the Active Antenna Systems (AAS), the weights of the antenna elements arranged vertically could be configured adaptively. Then, a degree of freedom (DOF) in the vertical plane is provided for system design. So the three-dimension MIMO (3D MIMO) could be realized to solve the actual implementation problem of the massive MIMO. However, in 3D massive MIMO systems, the pilot contamination problem studied in 2D massive MIMO systems and the inter-cell interference as well as inter-vertical sector interference in 3D MIMO systems with vertical sectorization exist simultaneously, when the number of antenna is not large enough. This paper investigates the interference management towards the above challenges in 3D massive MIMO systems. Here, vertical sectorization based on vertical beamforming is included in the concerned systems. Firstly, a cooperative joint vertical beams adjustment and pilot assignment scheme is developed to improve the channel estimation precision of the uplink with pilots being reused across the vertical sectors. Secondly, a downlink interference coordination scheme by jointly controlling weight vectors and power of vertical beams is proposed, where the estimated channel state information is used in the optimization modelling, and the performance loss induced by pilot contamination could be compensated in some degree. Simulation results show that the proposed joint optimization algorithm with controllable vertical beams` weight vectors outperforms the method combining downtilts adjustment and power allocation.

Preparation of monodisperse poly(styrene-co-divinylbenzene) microspheres by vibration dispersion method

Jiangyang Fan,Ye Wang,Guobing Li,Song Chen,Rongshuang Si 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.1

Monodisperse micron-size poly(styrene-co-divinylbenzene) (PST-DVB) microspheres were successfully prepared by vibration dispersion. A vibrator was used to generate a controlled vibration to jet from a single nozzle of 200 μm to produce uniform droplets. The effects of variations in selected process parameters upon the droplets formation and the diameter of the microspheres were investigated. It was demonstrated that changes in the velocity of oil phase, drive frequency and destabilization amplitude have significant effects on the formation of uniform droplets and the average diameter of the microspheres. Rational polynomial regression equations of the above parameters were established. Based on these equations, we could calculate the operation conditions to produce uniform droplets with the desirable diameter.

Multiple-Phase Energy Detection and Effective Capacity Based Resource Allocation Against Primary User Emulation Attacks in Cognitive Radio Networks

( Zongyi Liu ),( Guomei Zhang ),( Wei Meng ),( Xiaohui Ma ),( Guobing Li ) 한국인터넷정보학회 2020 KSII Transactions on Internet and Information Syst Vol.14 No.3

Cognitive radio (CR) is regarded as an effective approach to avoid the inefficient use of spectrum. However, CRNs have more special security problems compared with the traditional wireless communication systems due to its open and dynamic characteristics. Primary user emulation attack (PUEA) is a common method which can hinder secondary users (SUs) from accessing the spectrum by transmitting signals who has the similar characteristics of the primary users’ (PUs) signals, and then the SUs’ quality of service (QoS) cannot be guaranteed. To handle this issue, we first design a multiple-phase energy detection scheme based on the cooperation of multiple SUs to detect the PUEA more precisely. Second, a joint SUs scheduling and power allocation scheme is proposed to maximize the weighted effective capacity of multiple SUs with a constraint of the average interference to the PU. The simulation results show that the proposed method can effectively improve the effective capacity of the secondary users compared with the traditional overlay scheme which cannot be aware of the existence of PUEA. Also the good delay QoS guarantee for the secondary users is provided.

ROCK1 induces dopaminergic nerve cell apoptosis via the activation of Drp1-mediated aberrant mitochondrial fission in Parkinson’s disease

Qian Zhang,Changpeng Hu,Jingbin Huang,Wuyi Liu,Wenjing Lai,Faning Leng,Qin Tang,Yali Liu,Qing Wang,Min Zhou,Fangfang Sheng,Guobing Li,Rong Zhang 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

Dopamine deficiency is mainly caused by apoptosis of dopaminergic nerve cells in the substantia nigra of themidbrain and the striatum and is an important pathologic basis of Parkinson’s disease (PD). Recent research has shownthat dynamin-related protein 1 (Drp1)-mediated aberrant mitochondrial fission plays a crucial role in dopaminergicnerve cell apoptosis. However, the upstream regulatory mechanism remains unclear. Our study showed that Drp1knockdown inhibited aberrant mitochondrial fission and apoptosis. Importantly, we found that ROCK1 was activated inan MPP+-induced PD cell model and that ROCK1 knockdown and the specific ROCK1 activation inhibitor Y-27632blocked Drp1-mediated aberrant mitochondrial fission and apoptosis of dopaminergic nerve cells by suppressing Drp1dephosphorylation/activation. Our in vivo study confirmed that Y-27632 significantly improved symptoms in a PDmouse model by inhibiting Drp1-mediated aberrant mitochondrial fission and apoptosis. Collectively, our findingssuggest an important molecular mechanism of PD pathogenesis involving ROCK1-regulated dopaminergic nerve cellapoptosis via the activation of Drp1-induced aberrant mitochondrial fission.