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China Ocean Engineering 2009年第4期23卷 679-694页

作者： Dong-Ha LEE Hong-sic YUN Department of Civil Architectural and Environmental System EngineeringSungkyunkwan University

The national benchmarks on islands were mostly established by trigonometric leveling in Korea. This method results in inaccuracy, which is a serious problem in Geoga Grand Bridge construction work that tried to link the mainland and the islands. The Geoga Grand Bridge （Pusan-Geoje fixed link project） was selected as the study area, a huge construction work in Korea that will connect the mainland （Pnsan） and an island （Gecje island）. However, the orthometric heights issued at benchmarks （JINH and GOFJ） were not consistent, because they did not refer to the same zero point, which would make the linking of the sections problematic. This paper introduces the precise local geoidas a vertical datum for the construction area in order to establish a consistent height system. To determine the precise local geoid for the construction area, we firstly developed a precise gravimetric geoid for Korea and its adjoining seas as a whole. This gravimetric geoid was developed by use of all available gravity data, including surface and satellite data on land and on the ocean. The gravimetrie gecid was computed by spherical fast fourier transform with modified Stokes＇ kernels. The remove-restore technique was used to eliminate the terrain effects by use of the RTM reduction and to determine the residual geoid by combining the GGM02S/EGM96 geopotential model, free-air gravity anomalies and high-resolutinn DEM data. Finally, the gravimetric model was fitted to the geoid heights obtained from GPS and tide observations （Ncps/Tiae） by least square coUocatian, to provide the final GPS-consistent local precise geoid model. The post-fit error （std. dev. ） of the final geoid to the NetS/Tide derived from GPS and tide observations was ± 2.2 cm for the construction area. We solved the height inconsistency problem by calculating the orthometric height of the benchmarks and the cnntrol points using the final geoid model. Also, the highly accurate orthometric height was estimated through the GPS/lev

关键词： precise local geoid consistent height system gravity observations GPS! Tide observations least squares fitting

Preparation and heat insulating capacity of Sm2Zr2O7-sic composites based on photon thermal transport

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Journal of Advanced Ceramics 2020年第4期9卷 454-461页

作者： Zhuang Ma Qi Zhang ling Liu Yanbo Liu School of Materials Science and Engineering Beijing Institute of TechnologyBeijing100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing401120China

A series of Sm2Zr2O7-sic composites doped with different volume fraction and particle size of sic were prepared by hot pressing at 1300°*** phase of the composites prepared is P-Sm2Zr2O7 and C-sic,and no other diffraction peaks exist,which indicates that Sm2Zr2O7 has great chemical compatibility with *** thermal conductivity and phonon thermal conductivity of the Sm2Zr2O7-sic composites are measured by the laser pulse *** photon thermal conductivity of the composites is obtained by subtracting the phonon thermal conductivity from the total thermal *** results show that the photon thermal conductivity of Sm2Zr2O7-sic composites is lower than that of pure *** photon thermal conductivity of Sm2Zr2O7-sic composites decreases first and then increases with the increase of sic particle ***2Zr2O7-(5 vol%,10µm)sic composite has the lowest photon thermal conductivity.

关键词： rare-earth zirconates thermal conductivity photon thermal transport

3D Face Reconstruction from a Single Image Using a Combined PCA-LPP Method

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Computers, Materials & Continua 2023年第3期74卷 6213-6227页

作者： Jee-sic Hur Hyeong-Geun Lee Shinjin Kang Yeo Chan Yoon Soo Kyun Kim Department of Computer Engineering Jeju National UniversityJeju63243Korea School of Games Hongik UniversitySejong30016Korea Department of Artificial Intelligence Jeju National UniversityJeju63243Korea

In this paper, we proposed a combined PCA-LPP algorithm toimprove 3D face reconstruction performance. Principal component analysis(PCA) is commonly used to compress images and extract features. Onedisadvantage of PCA is local feature loss. To address this, various studies haveproposed combining a PCA-LPP-based algorithm with a locality preservingprojection (LPP). However, the existing PCA-LPP method is unsuitable for3D face reconstruction because it focuses on data classification and *** the existing PCA-LPP, the adjacency graph, which primarily shows the connectionrelationships between data, is composed of the e-or k-nearest neighbortechniques. By contrast, in this study, complex and detailed parts, such aswrinkles around the eyes and mouth, can be reconstructed by composing thetopology of the 3D face model as an adjacency graph and extracting localfeatures from the connection relationship between the 3D model *** verified the effectiveness of the proposed method. When theproposed method was applied to the 3D face reconstruction evaluation set,a performance improvement of 10% to 20% was observed compared with theexisting PCA-based method.

关键词： Principal component analysis locality preserving project 3DMM face reconstruction face modeling

Electrochemically metal-doped reduced graphene oxide films:Properties and applications

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Journal of Materials Science & Technology 2020年第5期40卷 72-80页

作者： Myung-sic Chae Tae Ho Lee Kyung Rock Son Tae Hoon Park Kyo Seon Hwang Tae Geun Kim School of Electrical Engineering Korea UniversityAnam-ro 145Seongbuk-guSeoul 02841South Korea Department of Clinical Pharmacology and Therapeutics College of MedicineKyung Hee UniversitySeoul 02447South Korea

The fine control of doping levels in graphene materials such as reduced graphene oxide(RGO)is important to properly manipulate their ambipolar transport characteristics for various device ***,conventional doping methods involve complex chemical reactions,large-scale doping processes,and poor ***,a simple and controllable electrochemical doping treatment(EDT),performed via the conductive channels created at the RGO surface by the application of an electric field,is introduced to tailor the electrical properties of RGO films.X-ray photoelectron spectroscopy and Raman spectroscopy measurements are performed to detect the presence of Ni atoms in RGO films after the EDT(EDT-RGO).Then,EDT-RGO field-effect transistors(FETs)are fabricated with different doping areas(0 to 100%fractional area)on the RGO active channel to investigate the effect and selective-area doping capability of the *** to p-type doping compensation by the intercalated Ni atoms,the electron mobility of the EDT-RGO FET decreases from 1.40 to 0.12 cm2 V-1s-1 compared with that of the undoped RGO-FET,leading to the conversion from ambipolar to unipolar p-type transfer characteristics.

关键词： Reduced graphene oxide Electrochemical doping treatment Electrical breakdown process Field-effect transistor

Uplink NOMA signal transmission with convolutional neural networks approach

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Journal of Systems Engineering and Electronics 2020年第5期31卷 890-898页

作者： LIN chuan CHANG Qing LI Xianxu School of Electronic and Information Engineering Beihang UniversityBeijing 100191China State Grid Information and Telecommunication Branch Beijing 100761China

Non-orthogonal multiple access(NOMA), featuring high spectrum efficiency, massive connectivity and low latency, holds immense potential to be a novel multi-access technique in fifth-generation(5G) communication. Successive interference cancellation(sic) is proved to be an effective method to detect the NOMA signal by ordering the power of received signals and then decoding them. However, the error accumulation effect referred to as error propagation is an inevitable problem. In this paper,we propose a convolutional neural networks(CNNs) approach to restore the desired signal impaired by the multiple input multiple output(MIMO) channel. Especially in the uplink NOMA scenario,the proposed method can decode multiple users' information in a cluster instantaneously without any traditional communication signal processing steps. Simulation experiments are conducted in the Rayleigh channel and the results demonstrate that the error performance of the proposed learning system outperforms that of the classic sic detection. Consequently, deep learning has disruptive potential to replace the conventional signal detection method.

关键词： non-orthogonal multiple access(NOMA) deep learning(DL) convolutional neural networks(CNNs) signal detection

Novel multi-tap analog self-interference cancellation architecture with shared phase-shifter for full-duplex communications

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Science China(Information Sciences) 2017年第10期60卷 139-154页

作者： Hongtao LU chuan HUANG Shihai SHAO Youxi TANG National Key Laboratory of Science and Technology on Communications University of Electronic Science and Technology of China

Multi-tap analog self-interference(SI) cancellation structures adopt parallel taps to reconstruct and then cancel SI in full-duplex radios. Each tap is usually comprised of one fixed delay line, one variable attenuator, and one optional variable phase shifter. To balance the quantity of the variable phase shifters and the achievable SI cancellation(sic) performance, this paper proposes a novel analog sic cancellation structure,called shared-phase-shifter constrained multi-tap structure(SMTS). In the proposed architecture, all taps share one phase shifter to emulate the dominated phase offset of the SI channel, which reduces the complexity of the implementation of the multi-tap analog sic structure and avoids the sic performance degradation. Then, the proposed SMTS and the existing structures are compared in terms of sic performance and power ***, extensive simulations show that SMTS provides the close-to-optimal sic performance as well as the lowest power dissipation relative to the existing multi-tap structures.

关键词： full-duplex multi-tap structure power dissipation phase shifter self-interference cancellation

Adsorption of Au on β-sic(111) Surfaces

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Chinese Physics Letters 1992年第2期9卷 101-104页

作者： LU Wenchang YE ling ZHANG Kaiming Department of Physics Fudan UniversityShanghai 200433

The adsorption properties of Au on β-sic(111)surfaces are studied using the charge self-consistent extended Hiickel *** intermixing between Au atom and β-sic could happen only on the Si-terminated(111)*** the case of Si~terminated,there is a intrinsic surface state in the energy gap,and the Fermi energy is pinned at this surface *** in the case of C-terminated,the surface state exists near the top of the valence band.

关键词： surface terminated surface

Fabrication of 2D C_f/sic Composites by Liquid Silicon Infiltration

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Journal of the Chinese Ceramic Society 2015年第4期 198-203页

作者： ling Yihui JIANG Pinyi HUANG Xiangdong College of Materials Sciences and Engineering Fuzhou University Fuzhou Ceravite New Materials Development Company Limited

The carbon/carbon(C/C) composite was prepared by repeatedly overlapping the layers of 2D carbon cloths, and the 2D C_f/sic composites were subsequently prepared in vacuum by a liquid silicon infiltration process. The flexural strength of samples obtained under different preparation conditions was investigated. The results show that the composite has a better performance when the mass of silicon powder is 1.5 times greater than that of C/C composite, the temperature of silicon infiltration is 1550 ℃ and the holding time of silicon infiltration is 3 h. The density and flexural strength of the composite are 2.15 g/cm^3 and 128 MPa, respectively, and the thickness of the sic layer is 12 μm.

关键词： 2D C_f/sic composites liquid silicon infiltration preparation technology flexural strength

Fabrication of mullite fiber reinforced sic porous ceramic

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Fabrication of mullite fiber reinforced SIC porous ceramic