Off-grid direction-of-arrival estimation for wideband noncircular sources

Xiaoyu Zhang1,Haihong Tao,Ziye Fang,Jian Xie 한국전자통신연구원 2023 ETRI Journal Vol.45 No.3

Researchers have recently shown an increased interest in estimating the direction-of-arrival (DOA) of wideband noncircular sources, but existing studies have been restricted to subspace-based methods. An off-grid sparse recovery-based algorithm is proposed in this paper to improve the accuracy of existing algorithms in low signal-to-noise ratio situations. The covariance and pseudo covariance matrices can be jointly represented subject to block sparsity constraints by taking advantage of the joint sparsity between signal components and bias. Furthermore, the estimation problem is transformed into a single measurement vector problem utilizing the focused operation, resulting in a significant reduction in computational complexity. The proposed algorithm's error threshold and the Cramer–Rao bound for wideband noncircular DOA estimation are deduced in detail. The proposed algorithm's effectiveness and feasibility are demonstrated by simulation results.

A New ent-Kaurane type Diterpenoid Glycoside from Inula japonica Thunb

Jiang Jiang Qin,Jia Xian Zhu,Wei Dong Zhang1,2,Yan Zhu,Jian Jun Fu,Xiao Hua Liu,Hui Zi Jin 대한약학회 2009 Archives of Pharmacal Research Vol.32 No.10

A new ent-kaurane type diterpenoid glycoside, 17-O-β-D-glucopyranosyl-16α-ent-kauran-19-oic acid (1), together with 17-hydroxy-16α-ent-kauran-19-oic acid (2), 16α,17-dihydroxyl-ent-kauran-19-oic acid (3), and 16α-hydroxy-17-acetoxy-ent- kauran-19-oic acid (4) were isolated from the aerial parts of Inula japonica Thunb. The structure of 1 was determined mainly by use of 1D and 2D NMR spectroscopic techniques including HSQC, 1H-1H COSY, HMBC, and NOESY. In addition, 4 exhibited significant inhibitory activity on NO production in LPS-stimulated RAW264.7 cells with IC50 value of 14.3 μg/mL.

Microstructure and Compression Strength of W/HfC Composites Synthesized by Plasma Activated Sintering

Jian Zhang,Shuai Ma,Jiawen Zhu,Kejia Kang,Guoqiang Luo,Chuandong Wu,Qiang Shen,Lianmeng Zhang 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.2

In this work, W/HfC composite materials were synthesized using plasma activated sintering. The influence of the sinteringtemperature and HfC weight fraction on the relative density, microstructure and compression strength were investigated. The results demonstrated that the sintering temperature and the HfC content significantly affected the microstructure of W/HfC composites. Moreover, the grain size of the W/HC composites decreased and the mechanical properties were improvedremarkably due to the addition of HfC. The majority of HfC particles reacted with oxygen impurities to generate HfO2,whichpurified the grain boundaries and refined the grain size of the W matrix. The optimum content of HfC is 2 wt%, at which ahigh compressive strength of 1.98 GPa and a high strain of 34.7% were obtained.

Fashion Corporate Social Responsibility, Corporate Image, Product Preference, and Purchase Intention: Chinese Consumers’ Perspectives

Jian Zhang,Yu Hua Cui 한국패션비즈니스학회 2018 패션 비즈니스 Vol.22 No.6

In this age of information, companies are losing grip of their image. Perhaps this explains the reason why corporate social responsibility (CSR) has become somewhat of a buzzword among established fashion industry leaders —companies seem determined to show stakeholders that they have values, are responsible, and they are driven by more by values than the prospects of financial gain. This study assessed the effect of CSR have in the fashion industry on the corporate image, product preference, and purchase intention in China. Three hundred native residents in China participated in an online survey from 1-12th Jan 2017. The results were as follows: (1) CSR consists of five components; economic responsibility, ethical responsibility, environmental protection, consumer protection, and philanthropic responsibility. (2) Both economic and ethical responsibilities have significant positive effects on corporate image, while perceived CSR does not have significant effect on product preference or purchase intention. (3) Consumers’ product preference and perceptions regarding corporate image influence their intention on making a purchase. These findings might operationally assist Korean fashion corporations to identify and address the critical aspects of CSR management which will improve their image as good corporate citizens and foster favorable attitudes toward fashion products from China. Further results and direction of future research were discussed.

Tetrazolium Violet Induced Apoptosis and Cell Cycle Arrest in Human Lung Cancer A549 Cells

( Jian Mei Lu ),( Xiao Hong Zhang ),( Nan Zhang ),( Qing Zhong Kong ),( Yun Feng Zhao ) 한국응용약물학회 2012 Biomolecules & Therapeutics(구 응용약물학회지) Vol.20 No.2

Tetrazolium violet is a tetrazolium salt and has been proposed as an antitumor agent. In this study, we reported for the fl rst time that tetrazolium violet not only inhibited human lung cancer A549 cell proliferation but also induced apoptosis and blocked cell cycle progression in the G1 phase. The results showed that tetrazolium violet signifl cantly decreased the viability of A549 cells at 5-15 M. Tetrazolium violet -induced apoptosis in A549 cells was confl rmed by H33258 staining assay. In A549, tetrazolium violet blocked the progression of the cell cycle at G1 phase by inducing p53 expression and further up-regulating p21/WAF1 expression. In addition, an enhancement in Fas/APO-1 and its two forms of ligands, membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), as well as caspase, were responsible for the apoptotic effect induced by tetrazolium violet. The conclusion of this study is that tetrazolium violet induced p53 expression which caused cell cycle arrest and apoptosis. These fl ndings suggest that tetrazolium violet has strong potential for development as an agent for treatment lung cancer.

Personalized Context-aware Recommendation Approach for Web Services

Zhang Xue-Jie,Wang Zhi-Jian,Zhang Wei-Jiang 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.8

With the increasing number of Web services, the goal of consumers becomes to discover and use services that lead to their experiencing the highest quality. Quality of Service (QoS) is important to evaluate the QoS performance of services to differentiate the qualities of service candidates. QoS is highly related to context information since service consumers are typically distributed in different geographical locations. Their experience is usually different. Invoking a huge number of Web services for consumers to predict the quality is time-consuming, resource- consuming, and sometimes even impractical. To address the challenge, this paper proposes a personalized context-aware recommendation approach for predicting the QoS of Web services and designs a prediction framework. This algorithm is a hybrid of the model-based and memory-based collaborative filtering algorithms. In our experiment, we collect QoS information from geographically distributed service consumers through the framework. Based on the QoS and context information, we predict the quality of services. As a result, we can obtain a list of recommended services for selection. Finally, the experiment shows that the algorithm using context information achieves better prediction.

Seismic Behavior of Low-rise Concrete Shear Wall with Single Layer of Web Reinforcement and Inclined Rebars: Restoring Force Model

Jian-Wei Zhang,Wen-Bin Zheng,Wan-Lin Cao,Hong-Ying Dong,Wan-Di Li 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.3

In order to study the restoring force model of low-rise concrete shear wall with single layer of web reinforcement and inclined rebars, a series of specimens were investigated by quasi-static tests. Based on the fitting of experimental data and theoretical analysis, the restoring force model considering four characteristic points (crack point, yield point, peak point and failure point) and degradation of unloading stiffness was established. The hysteretic rule of restoring force model was determined by analyzing characteristic of hysteresis curve for cyclic loading tests. The results show that skeleton curves and hysteresis curves calculated by the restoring force model are in good agreement with the test curves, which can provide reference for the elastic-plastic dynamic analysis of low-rise concrete shear walls with single layer of web reinforcements and inclined rebars. Shaking table tests of two low-rise concrete shear walls were also conducted to investigate dynamic performance and the seismic damage mechanism of low-rise concrete shear wall with single layer of web reinforcement and inclined rebars. Research on dynamic nonlinear simplified model of SAP2000 shows thatthe proposed restoring force model can be used to analyze the elastic and elastic-plastic dynamic response for the low-rise concrete shear wall with single layer of web reinforcement and inclined rebars.

Isolation and Characterization of Plant Growth-Promoting Rhizobacteria from Wheat Roots by Wheat Germ Agglutinin Labeled with Fluorescein Isothiocyanate

Jian Zhang,Jingyang Liu,Liyuan Meng,Zhongyou Ma,Xinyun Tang,Yuanyuan Cao,Leni Sun 한국미생물학회 2012 The journal of microbiology Vol.50 No.2

Thirty-two isolates were obtained from wheat rhizosphere by wheat germ agglutinin (WGA) labeled with fluorescein isothiocyanate (FITC). Most isolates were able to produce indole acetic acid (65.6%) and siderophores (59.3%), as well as exhibited phosphate solubilization (96.8%). Fourteen isolates displayed three plant growth-promoting traits. Among these strains, two phosphate-dissolving ones, WS29 and WS31, were evaluated for their beneficial effects on the early growth of wheat (Triticum aestivum Wan33). Strain WS29and WS31 significantly promoted the development of lateral roots by 34.9% and 27.6%, as well as increased the root dry weight by 25.0% and 25.6%, respectively, compared to those of the control. Based on 16S rRNA gene sequence comparisons and phylogenetic positions, both isolates were determined to belong to the genus Bacillus. The proportion of isolates showing the properties of plant growth-promoting rhizobacteria (PGPR) was higher than in previous reports. The efficiency of the isolation of PGPR strains was also greatly increased by WGA labeled with FITC. The present study indicated that WGA could be used as an effective tool for isolating PGPR strains with high affinity to host plants from wheat roots. The proposed approach could facilitate research on biofertilizers or biocontrol agents.

Grouting effects evaluation of water-rich faults and its engineering application in Qingdao Jiaozhou Bay Subsea Tunnel, China

Zhang, Jian,Li, Shucai,Li, Liping,Zhang, Qianqing,Xu, Zhenhao,Wu, Jing,He, Peng Techno-Press 2017 Geomechanics & engineering Vol.12 No.1

In order to evaluate the grouting effects of water-rich fault in tunnels systematically, a feasible and scientific method is introduced based on the extension theory. First, eight main influencing factors are chosen as evaluation indexes by analyzing the changes of permeability, mechanical properties and deformation of surrounding rocks. The model of evaluating grouting effects based on the extension theory is established following this. According to four quality grades of grouting effects, normalization of evaluation indexes is carried out, aiming to meet the requirement of extension theory on data format. The index weight is allocated by adopting the entropy method. Finally, the model is applied to the grouting effects evaluation in water-rich fault F4-4 of Qingdao Jiaozhou Bay Subsea Tunnel, China. The evaluation results are in good agreement with the test results on the site, which shows that the evaluation model is feasible in this field, providing a powerful tool for systematically evaluating the grouting effects of water-rich fault in tunnels.

A new geopolymeric grout blended completely weathered granite with blast-furnace slag

Zhang, Jian,Li, Shucai,Li, Zhaofeng,Li, Hengtian,Du, Junqi,Gao, Yifan,Liu, Chao,Qi, Yanhai,Wang, Wenlong Techno-Press 2020 Advances in concrete construction Vol.9 No.6

In order to reduce the usage of cement slurry in grouting engineering and consume the tunnel excavation waste soil, a new geopolymeric grouting material (GGM) was prepared by combine completely weathered granite (CWG) and blast-furnace slag (BFS), which can be applied to in-situ grouting treatment of completely weathered granite strata. The results showed CWG could participate in the geopolymerization process, and GGM slurry has the characteristics of short setting time, high flowability, low viscosity, high stone rate and high mechanical strength, and a design method of grouting pressure based on viscosity evolution was proposed. By adjusted the content of completely weathered granite and alkali activator concentration, the setting time of GGM were ranged from 5 to 30 minutes, the flowability was more than 23.5 cm, the stone rate was higher than 90%, the compressive strength of 28 days were 7.8-16.9 MPa, the porosity were below 30%. This provides a novel grouting treatment and utilizing excavated soil of tunnels in the similar strata.