Low Complexity Hybrid Precoding in Millimeter Wave Massive MIMO Systems

Tongtong Cheng,Yigang He,Yuting Wu,Shuguang Ning,Yongbo Sui,Yuan Huang 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.4

As a preprocessing operation of transmitter antennas, the hybrid precoding is restricted by the limited computing resources of the transmitter. Therefore, this paper proposes a novel hybrid precoding that guarantees the communication efficiency with low complexity and a fast computational speed. First, the analog and digital precoding matrix is derived from the maximum eigenvectors of the channel matrix in the sub-connected architecture to maximize the communication rate. Second, the extended power iteration (EPI) is utilized to obtain the maximum eigenvalues and their eigenvectors of the channel matrix, which reduces the computational complexity caused by the singular value decomposition (SVD). Third, the Aitken acceleration method is utilized to further improve the convergence rate of the EPI algorithm. Finally, the hybrid precoding based on the EPI method and the Aitken acceleration algorithm is evaluated in millimeter-wave (mmWave) massive multiple-input and multiple-output (MIMO) systems. The experimental results show that the proposed method can reduce the computational complexity with the high performance in mmWave massive MIMO systems. The method has the wide application prospect in future wireless communication systems.

A new bismuth vanadate photocatalyst of Bi₂₃V₄O_44.5 nanoplates with layered δ-Bi₂O₃ based fluorite-type superstructures

Lu, Yuting,Chen, Luyang,Li, Yuze,Xie, Hongde,Cheng, Han,Jin Seo, Hyo Elsevier 2016 Materials letters Vol.164 No.-

<P><B>Abstract</B></P> <P>The work reports the large-scale synthesis and photocatalytic activity of Bi<SUB>23</SUB>V<SUB>4</SUB>O<SUB>44.5</SUB> nanoplates. The structural refinement was conducted in the layered δ-Bi<SUB>2</SUB>O<SUB>3</SUB> based superstructuLre. The detailed surface properties were characterized. Bi<SUB>23</SUB>V<SUB>4</SUB>O<SUB>44.5</SUB> shows efficient absorption in visible region with a band-gap of 2.384eV from the hybridization of Bi-6s and O-2p orbitals. Particularly, Bi<SUB>23</SUB>V<SUB>4</SUB>O<SUB>44.5</SUB> shows an efficient photodegradation for methylene blue (MB). The photocatalysis benefits from the layered B–O structure characteristic and the codoped defects of V<SUP>4+</SUP>/V<SUP>5+</SUP> ions in the lattices. Bi<SUB>23</SUB>V<SUB>4</SUB>O<SUB>44.5</SUB> nanoplates could be a potential photocatalyst.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Bi<SUB>23</SUB>V<SUB>4</SUB>O<SUB>44.5</SUB> nanoplates were prepared by the Pechini method. </LI> <LI> It has a narrow band-gap of 2.384eV from hybridization of Bi-6s and O-2p. </LI> <LI> Bi<SUB>23</SUB>V<SUB>4</SUB>O<SUB>44.5</SUB> has photocatalysis report visible-light-irradiation. </LI> <LI> Photocatalysis is due to layered δ-Bi<SUB>2</SUB>O<SUB>3</SUB>-like structure and codoped V<SUP>4+</SUP>/V<SUP>5+</SUP> ions. </LI> </UL> </P>

Improvement of two-phase flow distribution in the header of a plate-fin heat exchanger

Tu, Xin-Cheng,Wu, Yuting,Kim, Hyoung-Bum Elsevier 2018 INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER - Vol.123 No.-

<P><B>Abstract</B></P> <P>The two-phase (liquid and gas) flow distribution in the header of a plate-fin heat exchanger was experimentally investigated. Small mass fractions of the liquid phase in the liquefaction process of natural gas were considered in this study. The liquid and gas flow velocity were measured using optical methods such as PIV/PTV/LIF. The flow maldistribution of liquid and gas flows was quantified and addressing this problem by attaching a porous baffle or modifying the inlet nozzle configuration was studied. The results showed that a vane swirler with a diffuser enhanced the flow distribution of both the liquid and gas phases fluid.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Two-phase flow distribution in the header of plate-fin heat exchanger was quantified. </LI> <LI> The effect of porous baffle and other passive jet modifiers was investigated. </LI> <LI> Vane swirler and diffuser improves the two-phase flow distribution. </LI> </UL> </P>

Exogenous 5-aminolevulinic acid promotes plant growth and salinity tolerance of grape rootstocks in coastal areas

Zheng Weiwei,Tian Yuting,Shi Haili,Chen Miaomiao,Hong Seungbeom,Xu Kai,Cheng Jianhui,Zang Yunxiang 한국원예학회 2023 Horticulture, Environment, and Biotechnology Vol.64 No.2

Salinity stress is a key factor aff ecting grape production in coastal areas. Two grape rootstock cultivars, ‘Beta’ (sensitive to salt stress) and ‘3309 C’ (resistant to salt stress), were used to investigate the physiological role of 5-aminolevlinic acid (5-ALA) in salinity tolerance. Functional capacities in the rhizosphere, leaf phenotype, photosynthetic parameters, antioxidant enzymes activities and certain physiological indexes were determined after treatment with seawater or seawa- ter followed by 100 mg/L 5-ALA application. The results showed that the functional capacities of the rhizosphere were distinct between the two management regimes. Microbial biomass and soil enzyme activities were reduced by salinity but promoted by 5-ALA. Salinity also suppressed the overall plant growth, leaf chlorophyll content, photosynthetic rate, maxi- mal photochemical effi ciency (Fv/Fm), photochemical quenching (qP), electron transport rate (ETR), root activity, ATP content, ATPase activity, and activities of the antioxidant enzymes ascorbate peroxidase (APX), peroxidase (POD), cata- lase (CAT), and superoxide dismutase (SOD) in both cultivars. Although plant growth, chlorophyll content, and activities of antioxidant enzymes in Beta were decreased to a greater extent than those in 3309 C under salinity stress, exogenous application of 5-ALA signifi cantly improved plant growth along with enhancement of all the above photosynthetic param- eters and activities of the four antioxidant enzymes in both cultivars. Seawater treatment alone signifi cantly increased non- photochemical quenching (NPQ), relative electrical conductivity (REC), and malondialdehyde (MDA) contents in leaves, especially for Beta. However, 5-ALA treatment decreased the levels of NPQ, REC, and MDA, but increased ATP content and ATPase activity in roots and leaves of both cultivars. Thus, application of 5-ALA would be benefi cial to improve the salt tolerance of grape rootstocks grown in coastal areas.

MULTIDISCIPLINARY DESIGN OPTIMIZATION FOR FRONT STRUCTURE OF AN ELECTRIC CAR BODY-IN-WHITE BASED ON IMPROVED COLLABORATIVE OPTIMIZATION METHOD

Wenwei Wang,Fengling Gao,Yuting Cheng,Cheng Lin 한국자동차공학회 2017 International journal of automotive technology Vol.18 No.6

In this investigation, an Improved Collaborative Optimization (ICO) method based Multidisciplinary Design Optimization (MDO) framework for front structure of an electric car body-in-white (BIW) is presented. ICO method based on 1-norm and dynamic flabby coefficient, which shows relatively high efficiency and accuracy, is first proposed here and prepared to conduct MDO in this work. Finite element analysis (FEA) results of the baseline design for an integral battery electric car body structure show that its front part needs to be optimized designed in the consideration of full-lap frontal crashworthiness. Selecting the thicknesses of 5 components, with global mass and free basic frequency constraints, a multidisciplinary size optimization problem is implemented using both ICO and standard CO methods combined with OLHS technique, metamodel and SQL algorithm. Optimal scheme based on ICO method is preferred and selected for its better performance compared with result calculated by standard CO method. The energy absorption of redesigned front body structure is finally raised by 14.2 % with 55 iterations.

Electrochemical Determination of Paracetamol at Poly(3-Methylthiophene)/Reduced Graphene Oxide Modified Glassy Carbon Electrode

Caiwei Li,Weimeng Si,Yuting Wu,Cheng Zhang,Wu Lei,Qingli Hao 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.09

Poly(3-methylthiophene)/reduced graphene oxide (P3MT/RGO) modified glassy carbon electrode (GCE) was fabricated via a facile procedure. P3MT was directly electrodeposited on the RGO coated electrode and employed for the electrochemical detection of paracetamol (PCT). The morphology of composite was characterized by scanning electron microscopy (SEM). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to investigate the electrochemical behaviors of PCT on P3MT/RGO/GCE. Experimental parameters, such as the scan rates, polymerization laps and the pH of buffer solution were optimized. Under the optimal conditions, the anodic peak current in DPVs varies linearly with the concentration of PCT, and the limit of detection was 0.025 μM. Moreover, the proposed P3MT/RGO/GCE also exhibited superior stability and reproducibility.

The clustering of the SDSS-IV extended Baryon Oscillation Spectroscopic Survey DR14 quasar sample: anisotropic Baryon Acoustic Oscillations measurements in Fourier-space with optimal redshift weights

Wang, Dandan,Zhao, Gong-Bo,Wang, Yuting,Percival, Will J,Ruggeri, Rossana,Zhu, Fangzhou,Tojeiro, Rita,Myers, Adam D,Chuang, Chia-Hsun,Baumgarten, Falk,Zhao, Cheng,Gil-Marí,n, Hé,ctor,Ross, Oxford University Press 2018 MONTHLY NOTICES- ROYAL ASTRONOMICAL SOCIETY Vol.477 No.2

<B>Abstract</B><P>We present a measurement of the anisotropic and isotropic Baryon Acoustic Oscillations (BAO) from the extended Baryon Oscillation Spectroscopic Survey Data Release 14 quasar sample with optimal redshift weights. Applying the redshift weights improves the constraint on the BAO dilation parameter α(zeff) by 17 per cent. We reconstruct the evolution history of the BAO distance indicators in the redshift range of 0.8 &lt; z &lt; 2.2. This paper is part of a set that analyses the eBOSS DR14 quasar sample.</P>