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Optimized Content-Aware Image Resizing with Merging and Improved Importance Diffusion

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Journal of Harbin Institute of Technology(New Series) 2015年第2期22卷 67-73页

作者： danfeng zhao Bo Wang College of Information and Communication Engineering Harbin Engineering University

A simple and effective content-aware image resizing method is proposed based on the row / column merging and improved importance diffusion,which preserves the important regions in an image as well as the global visual effect. By repeatedly merging two rows / columns into one row / column or inserting a new row /column between two rows / columns, this method realizes image-resolution reduction and expansion. The importance of the merged row / column is promoted and diffused to four rows / columns around the merged one,which is to avoid the unwanted image distortions resulted from excessively merging of un-important regions. In addition,the proposed method introduces the direction of gradient vector in the low-pass filter to reduce the interference caused by complex texture background and protect important content better. Furthermore,according to human mechanics principles,different weights are given to the row and column direction components of gradient vectors which can obtain better global visual effect. Experimented results show that the proposed method satisfied in not only visual effect but also objective evaluation.

关键词： content-aware image resizing merging importance diffusion gradient vector

Simplified iterative algorithm for OFDM phase noise mitigation

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Journal of Systems Engineering and Electronics 2007年第4期18卷 716-720页

作者： Yang Jianhua zhao danfeng Yue Li zhao Chunhui Coll. of Information and Communication Engineering Harbin Engineering Univ. Harbin 150001 P. R. China

OFDM has been widely adopted in several communication systems. However, OFDM systems are very sensitive to the phase noise, which causes the CPE （common phase error） and ICI （inter-carrier interference）, and thus degrades the system performance significantly. Based on the IEEE 802.11a standard, a simplified iterative phase noise mitigation algorithm is proposed. The proposed algorithm has very low complexity, and requires no additional pilot information. The simulation result shows that good BER performance can be achieved through several few times of iteration.

关键词： phase noise OFDM systems IEEE 802.11a standard inter-carrier interference

Low-complexity iterative equalization for OTFS based on alternating minimization

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Journal of Systems Engineering and Electronics 2023年第4期34卷 851-860页

作者： HE Xin JIA Haoxiang SUN Yutong ZHOU Zijian zhao danfeng School of Information and Communication Engineering Harbin Engineering UniversityHarbin 150001China

To achieve robust communication in high mobility scenarios,an iterative equalization algorithm based on alternating minimization(AM)is proposed for the orthogonal time frequency space(OTFS)*** algorithm approximates the equalization problem to a convex function optimization problem in the real-valued domain and solves the problem iteratively using the AM *** the iterative process,the complexity of the proposed algorithm is reduced further based on the study of the cyclic structure and sparse property of the OTFS channel matrix in the delay-Doppler(DD)*** new method for OTFS is simulated and verified in a high-speed mobile scenario and the results show that the proposed equalization algorithm has excellent bit error rate performance with low complexity.

关键词： orthogonal time frequency space(OTFS) alternating minimization(AM) high-speed mobile scenario iterative equalization

Novel joint encoding/decoding algorithms of fountain codes for underwater acoustic communication

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Journal of Systems Engineering and Electronics 2016年第4期27卷 772-779页

作者： Mingshen Liang Jinjue Duan danfeng zhao Jiaxi Si Xiangyu Song College of Information and Communication Engineering Harbin Engineering University

Fountain codes are considered to be a promising coding technique in underwater acoustic communication（UAC） which is challenged with the unique propagation features of the underwater acoustic channel and the harsh marine environment. And Luby transform（LT） codes are the first codes fully realizing the digital fountain concept. However, in conventional LT encoding/decoding algorithms, due to the imperfect coverage（IC） of input symbols and short cycles in the generator matrix, stopping sets would occur and terminate the decoding. Thus, the recovery probability is reduced,high coding overhead is required and decoding delay is *** issues would be disadvantages while applying LT codes in underwater acoustic communication. Aimed at solving those issues, novel encoding/decoding algorithms are proposed. First,a doping and non-uniform selecting（DNS） encoding algorithm is proposed to solve the IC and the generation of short cycles problems. And this can reduce the probability of stopping sets occur during decoding. Second, a hybrid on the fly Gaussian elimination and belief propagation（OFG-BP） decoding algorithm is designed to reduce the decoding delay and efficiently utilize the information of stopping sets. Comparisons via Monte Carlo simulation confirm that the proposed schemes could achieve better overall decoding performances in comparison with conventional schemes.

关键词： underwater acoustic communication(UAC) fountain codes non-uniform encoding hybrid decoding algorithm stopping sets

Low Complexity Multiuser Detection Algorithm for Multi-Beam Satellite Systems

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Journal of Harbin Institute of Technology(New Series) 2015年第5期22卷 105-109页

作者： Yang Wang danfeng zhao Xi Liao College of Information and Communication Engineering Harbin Engineering University

The minimum mean square error-successive interference cancellation( MMSE-SIC) multiuser detection algorithm has high complexity and long processing latency. A multiuser detection algorithm is proposed for multi-beam satellite systems in order to decrease the complexity and latency. The spot beams are grouped base on the distance between them in the proposed algorithm. Some groups are detected in parallel after a crucial group-wise interference cancellation. Furthermore, the multi-stage structure is introduced to improve the performance. Simulation results show that the proposed algorithm can achieve better performance with less complexity compared with the existing group detection algorithm. Moreover,the proposed algorithm using one stage can reduce the complexity over the fast MMSE-SIC and existing group detection algorithm by 9% and20. 9%. The processing latency is reduced significantly compared with the MMSE-SIC.

关键词： satellite communications multi-beam satellites multiuser detection complexity

Stability analysis of reef fish communities based on symbiotic graph model

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Aquaculture and Fisheries 2024年第6期9卷 1007-1017页

作者： danfeng zhao Yaru Lou Wei Song Dongmei Huang Xiaoliang Wang College of Information Technology Shanghai Ocean UniversityShanghai201306China Shanghai University of Electric Power Shanghai200090China East China Sea Information Center of the State Oceanic Administration Shanghai200136China

The community stability of coral reefs and fish is the focus of ecological monitoring of coral *** them,the realization of effective metrics of variations in reef fish communities(i.e.,the combined communities of coral reefs and fish)is important for analyzing the stability of communities as well as maintaining the ecological balance of coral *** on coral reef and fish data collected at ***’s Island from 2004 to 2010,this study proposes a symbiotic graph modeling method to express the biological relationships of reef fish communities,and a Pyramid Match graph kernel method for fusing Attributes(PMA)to quantify community fluctuations to measure interannual variability of *** results showed that the community similarity was low in 2006,2007,and *** total coral cover rate in the study area decreased by 32.04% from 2006 to 2007 and increased by 24% in *** total number of fish fell from 3780 in 2006 to 2596 in 2007 and rose to 6249 in *** them,the proportion of herbivorous fish decreased to 30.84% in ***,we have combined the Louvain algorithm with the proposed PMA method to effectively identify the regions that should be prioritized for *** were conducted on real datasets with good results,demonstrating the potential of the proposed method to assist in the analysis of community stability and identification of priority conservation areas.

关键词： Reef fish community Community stability Community variation Symbiotic graph model Graph kernel Conservation area

Defect engineering and Ni promoter synergistically accelerating electron transfer to Ru^(0) sites in UiO-66(Ce) for dicyclopentadiene hydrogenation under mild condition

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Nano Research 2024年第11期17卷 9550-9563页

作者： Rushuo Li Tao Ban danfeng zhao Jing Lin Zhiyuan Liu Linmeng Wang Xiubing Huang Zhiping Tao Ge Wang Beijing Advanced Innovation Center for Materials Genome Engineering Beijing Key Laboratory of Function Materials for Molecule and Structure Construction School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Sinopec Research Institute of Petroleum Processing Co. Ltd. Beijing 100083 China

Olefin hydrogenation under mild condition is crucial and challenging for industrial applications. Herein, defective UiO-66(Ce) was constructed by using cyanuric acid as the molecular etching “scissors” and further to synthesize heterogeneous catalyst with highly dispersed RuNi nanoparticles (Ru1Ni1.5@UiO-66(Ce)-12 h). The construction of Ce-O-Ru/Ni heterogeneous interfaces and Ni–Ru bonds provide electron transfer channels from Ce-oxo clusters and Ni species to Ru species. Furthermore, the microenvironment and electronic structure of Ru0 active sites were synergistically regulated by adjusting the content of metal-organic frameworks (MOFs) defects and Ni promoter, thereby enhancing the adsorption and activation ability of H–H and C=C bonds. Therefore, Ru1Ni1.5@UiO-66(Ce)-12 h achieved dicyclopentadiene saturated hydrogenation (100% conversion) to tetrahydrodicyclopentadiene (∼ 100% selectivity) under mild condition (35℃, 1 MPa) with only 25 min. Meanwhile, the sample exhibited excellent structural stability after 6 cycles test. This study provides a promising strategy for the rational design of remarkable noble metal-based catalysts for practical applications.

关键词： metal-organic frameworks defect engineering Ni promoter electron-rich Ru^(0)active sites dicyclopentadiene hydrogenation

An Improved Decoding Algorithm Based on Min-max for NB-LDPC Codes 36

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An Improved Decoding Algorithm Based on Min-max for NB-LDPC ...

Design of Raptor Design of Raptor-Like Rate Compatible SC Like Rate Compatible SC-LDPC Codes

第36届中国控制会议

作者： Mengzhu Chen Jin Xu Jun Xu danfeng zhao Jiahui Meng Wireless Technology preresearch Team ZTE Corporation College of Information and Communication Engineering Harbin Engineering University

ISBN: (纸本)9781538629185

When the code length is moderate,non-binary low-density parity-check（NB-LDPC） codes can achieve better error correcting performance than their binary counterparts at the expense of higher decoding *** check node processing is a major bottleneck of NB-LDPC *** this paper,Min-max decoding algorithm is proposed based on a new forward backward processing method of check nodes,select only a part of the most reliable information to the forward-backward calculation process,and change the variable nodes to check nodes（v-to-c） generation of *** this algorithm,a kind of code（768,1152） defined on GF（4） is simulated and compared with belief propagation in log domain（LOG-BP） decoding *** results show Min-max decoding algorithm reduce information storage requirements and the computational complexity,conducive to engineering implementation.

关键词： non-binary low density parity check codes Min-max decoding algorithm check nodes

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ZTE Communications 2022年第S01期20卷 16-21页

作者： SHI Xiangyi HAN Tongzhou TIAN Hai zhao danfeng College of Information and Communication Engineering Harbin Engineering UniversityHarbin 150001China

This paper proposes a family of raptor-like rate-compatible spatially coupled low-density parity-check(RL-RC-SC-LDPC)codes from RL-RC-LDPC block *** are two important *** is the performance of the base ***-LDPC codes have been adopted in the technical specification of 5G new radio(5G-NR).We use the 5G NR LDPC code as the base *** other is the edge coupling *** this regard,we have designed a rate-compatible coupling algorithm,which can improve performance under multiple code *** constructed RL-RC-SC-LDPC code property requires a large coupling length L and thus we improved the reciprocal channel approximation(RCA)algorithm and proposed a sliding window RCA *** can provide lower com-plexity and latency than RCA *** code family shows improved thresholds close to the Shannon limit and finite-length performance compared with 5G NR LDPC codes for the additive white Gaussian noise(AWGN)channel.

关键词： SC-LDPC code 5G NR LDPC code rate-compatibility threshold sliding win-dow RCA algorithm