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SAR Image Matching Algorithm Base on Improved Hu Invariant Moments
Lin Kuan,Zhang Yi,Dang Yawen,Huang Junheng 보안공학연구지원센터(IJSIP) 2015 International Journal of Signal Processing, Image Vol.8 No.1
SAR image matching as a key technology is valuable in theory and practicality. Recent years, wide attention has been paid to cross-correlation algorithm and Hu invariant moments algorithm in the image matching field. The paper introduces concept of the two methods, and takes samples to analyze them to summarize the merits and faults. These two methods are not so effectual for SAR image matching. So based on the traditional Hu invariants moments algorithm, a new kind of improved Hu invariant moments algorithm is proposed. The experimental results prove that the improved method is stable and reliable under some variations for rotation in SAR image matching.
Yueqin Shen,Xian Li,Yawen Huang,Guanjun Chang,Ke Cao,Junxiao Yang,Renyi Zhang,Xueying Sheng,Xu Ye 한국고분자학회 2016 Macromolecular Research Vol.24 No.7
pH and redox dual stimuli-responsive injectable hydrogels were prepared by cross-linking oxidized carboxymethyl cellulose (oxi-CMC) with 3,3'-dithiobis (propionohydrazide) (DTP) via Schiff base reaction under physiological condition. The hydrogels showed good performance such as tunable gelling time, appropriate rheology properties, high swelling ratio and low degradation rate. In vitro release studies confirmed that bovine serum albumin (BSA) as a model drug exhibited a sustainable release at pH 7.4 and an accelerated release under a lower pH 5.0 and/or reducing environments. The results signified that oxi-CMC/DTP hydrogels could be an attractive candidate for drug delivery system, tissue engineering or cell scaffold materials.
Transparent Lamellar Porous Material and Its Greatly Reduced Dielectric Constant
Lili Liu,Cuijiao Zhao,Yawen Huang,Xiaonan Wei,Hongtao Yu,Junxiao Yang 한국고분자학회 2017 Macromolecular Research Vol.25 No.10
One trend for low dielectric materials is to reach low dielectric constant values at as low porosity as possible. In this work, a lamellar porous material was prepared by spin-coating of poly(vinyl alcohol) (PVA)/manganese dioxide (MnO2) nanosheet composited film, followed by cross-linking of PVA and removing nanosheets. FTIR, XRD and TGA measurement results demonstrate that the templates were almost completely removed. SEM image shows that the etched PVA film has a lamellar porous structure. Dielectric test results indicate that at the porosity of only 17.5%, the dielectric constant of porous PVA is reduced to approximately half that of neat cross-linked PVA. The serial model shows a good consistence with experimental dielectric constant value. This explains well the high efficiency of lamellar porous structure in reducing dielectric constant.
Kun Fang,Xu Ye,Yawen Huang,Guanjun Chang,Junxiao Yang,Yueqin Shen 한국고분자학회 2015 Macromolecular Research Vol.23 No.6
Three original conjugated polymers were devised and synthesized via the alternating conjugated polymerization of the electron-donating monomer of the modified benzo[1,2-b:4,5-b']dithiophene (BDT) and electronaccepting monomers of perylene diimide (PDI), dithienyl-perylene diimide (DTPDI) and dithienocoronene diimide (DTCDI), respectively. The synthesized conjugated polymers presented excellent thermal stability (Td >400 oC) as well as broad absorption in visible region and narrow gap of energy level (1.80 to 2.01 eV). Moreover, P(BDT-DTCDI) exhibited strong fluorescence properties ( =736 nm with excitation at 680 nm). According to the theoretical calculations, P(BDT-PDI) and P(BDT-DTPDI) displayed significant polymer backbone torsion (41.44o and 39.64o), and P(BDT-DTCDI) had highly coplanar backbone with negligible angle between BDT and DTCDI. The results indicated that P(BDT-DTCDI) had potential applications in the fields of organic thin-film transistors (OTFTs) and fluorescence materials, and P(BDT-PDI) and P(BDT-DTPDI) could be used as a stable n-type semiconductor for polymer solar cells.
Nan Zhong,Xian Li,Huan Hu,Yawen Huang,Xu Ye,Junxiao Yang 한국고분자학회 2019 Macromolecular Research Vol.27 No.12
All-benzocyclobutene functionalized polycarbosilanes and the derived copolymers were successfully synthesized by ring-opening polymerization (ROP) of 1,1-dibenzocyclobutene-1-silacyclobutane (DBCBSCB) and 1,1-diphenylsiletane (DPSCB) using Karstedt’s catalyst. Adjusting the copolymerization ratio of DBCBSCB and DPSCB could afford to control the ultimate properties of the cured resins. The linear polycarbosilanes containing dibenzocyclobutene were directly cross-linked upon high temperature. With increasing the copolymerization ratio of DBCBSCB and DPSCB, the 5% weight loss temperature (T5%) of cured resins is increased from 450 °C to 506 °C under a nitrogen atmosphere, while the dielectric constant (k) is decreased from 2.60 to 2.42 at 10 MHz. The excellent thermostability and low-dielectric performance make such thermosets have potential application in the microelectronic industry.
Shengbo Zhang,Huan Hu,Hongtao Yu,Yawen Huang,Junxiao Yang 한국고분자학회 2017 Macromolecular Research Vol.25 No.4
Low dielectric materials show great application potential in future microelectronic industry. In this study, benzocyclobutene-functionalized polycarbosilane derived block copolymer, poly(carbosilane-b-lactide), was synthesized via sequential anionic polymerization of silacyclobutene and ring-opening polymerization of lactide. The block copolymer revealed microphase-separation behavior to form a well-defined morphology. Simultaneously, the sacrifice of polylactide blocks by thermal decomposition and thermally-induced reaction of benzocyclobutene produces cross-linked nanoporous polycarbosilane (PBCS). The dielectric constant of this nanoporous material reaches to around 2.1.