Sparse Channel Estimation of Single Carrier Frequency Division Multiple Access Based on Compressive Sensing

Zhong, Yuan-Hong,Huang, Zhi-Yong,Zhu, Bin,Wu, Hua Korea Information Processing Society 2015 Journal of information processing systems Vol.11 No.3

It is widely accepted that single carrier frequency division multiple access (SC-FDMA) is an excellent candidate for broadband wireless systems. Channel estimation is one of the key challenges in SC-FDMA, since accurate channel estimation can significantly improve equalization at the receiver and, consequently, enhance the communication performances. In this paper, we study the application of compressive sensing for sparse channel estimation in a SC-FDMA system. By skillfully designing pilots, their patterns, and taking advantages of the sparsity of the channel impulse response, the proposed system realizes channel estimation at a low cost. Simulation results show that it can achieve significantly improved performance in a frequency selective fading sparse channel with fewer pilots.

Sparse Channel Estimation of Single Carrier Frequency Division Multiple Access Based on Compressive Sensing

( Yuan Hong Zhong ),( Zhi Yong Huang ),( Bin Zhu ),( Hua Wu ) 한국정보처리학회 2015 Journal of information processing systems Vol.11 No.3

It is widely accepted that single carrier frequency division multiple access (SC-FDMA) is an excellent candidate for broadband wireless systems. Channel estimation is one of the key challenges in SC-FDMA, since accurate channel estimation can significantly improve equalization at the receiver and, consequently, enhance the communication performances. In this paper, we study the application of compressive sensing for sparse channel estimation in a SC-FDMA system. By skillfully designing pilots, their patterns, and taking advantages of the sparsity of the channel impulse response, the proposed system realizes channel estimation at a low cost. Simulation results show that it can achieve significantly improved performance in a frequency selective fading sparse channel with fewer pilots.

EFFECTS OF INJECTION TIMING ON TRANSIENT PERFORMANCE OF A REGULATED TWO-STAGE TURBOCHARGED DIESEL ENGINE WITH TURBINE BYPASS VALVE

Zhong Chang Liu,Xing Yuan,Jing Tian,Yong Qiang Han,Kai Bo Yu,Peng Kun Teng 한국자동차공학회 2018 International journal of automotive technology Vol.19 No.5

The object of this paper is to reduce soot emissions under typical 5s transient conditions of constant speed and increasing torque. And effects of fuel injection timing on combustion and emissions parameters were experimentally and numerically studied in a regulated two-stage turbocharged diesel engine with a turbine bypass valve (TBV). The test results indicated that: the smaller TBV opening could improve deterioration of smoke emissions and BSFC at medium and heavy loads. Afterward, the full-stage injection timing (FSIT) strategies (delaying injection timing during the entire transient process) could reduce soot and NOX emissions simultaneously. However, when TBV opening became larger, smoke emissions and BSFC were deteriorated gradually. Moreover, the sectional-stage injection timing (SSIT) strategies (advancing injection timing from 10 % load to a preset load and delaying injection timing from the preset load to 100 % load) could markedly reduce soot emissions by 75.8 % with TBV opening 20 %; the degradation of fuel consumption could be effectively suppressed. Finally, coupling the SSIT strategies with the TBV control strategies could significantly improve the transient performance.

Decreased Expression of FADS1 Predicts a Poor Prognosis in Patients with Esophageal Squamous Cell Carcinoma

Du, Yong,Yan, Shu-Mei,Gu, Wan-Yi,He, Fan,Huang, Li-Yun,Li, Mei,Yuan, Yan,Chen, Ren-Hui,Zhong, Qian,Li, Man-Zhi,Li, Yong,Zeng, Mu-Sheng Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.12

FADS1 (fatty acid desaturase 1) plays a crucial role in fatty acid metabolism, and it was recently reported to be involved in tumorigenesis. However, the role of FADS1 expression in esophageal squamous cell carcinoma (ESCC) remains unknown. In the current study, we investigated the expression and clinical pathologic and prognostic significance of FADS1 in ESCC. Immunohistochemical analyses revealed that 58.2% (146/251) of the ESCC tissues had low levels of FADS1 expression, whereas 41.8% (105/251) exhibited high levels of FADS1 expression. In positive cases, FADS1 expression was detected in the cytoplasm of cells. Correlation analyses demonstrated that FADS1 expression was significantly correlated with tumor location (p=0.025) but not with age, gender, histological grade, tumor status, nodal status or TNM staging. Furthermore, patients with tumors expressing high levels of FADS1had a longer disease-free survival time (p<0.001) and overall survival time (p <0.001). Univariate and multivariate analyses revealed that, along with nodal status, FADS1 expression was an independent and significant predictive factor (p<0.001). In conclusion, our study suggested that FADS1 might be a valuable biomarker and potential therapeutic target for ESCC.

Privet golden leaves adapt unexpectedly well to light changes

Ming Yuan,Bo Huang,Li-Hua Dong,Qiao-Hong Han,Yong Yang,Chun-Bang Ding,Chao Hu,Yang-Er Chen,Zhong-Wei Zhang,Shu Yuan 한국원예학회 2020 Horticulture, Environment, and Biotechnology Vol.61 No.4

Golden-leaf privet ( Ligustrum × vicaryi ) is widely used as a horticultural shrub because of its upper golden leaves, butits lower leaves are green. However, the putative mechanisms of its upper golden leaves and the leaf color changes inresponse to light shifts have not been well studied so far. Here, chlorophylls (Chl), carotenoids, and Chl precursors from bothgolden and green leaves grown in full sunlight (approximately 1200 μmol photons m −2 s −1 at noon) or low-light conditions(180 μmol m −2 s −1 ) were determined spectrophotometrically. In addition, their gas exchange parameters and Chl fl uorescencewere measured in situ. Metabolic fl ux analysis of chlorophyll intermediates indicated that the conversion of prochlorophyllideto chlorophyllide was signifi cantly blocked in golden leaves when compared with green leaves. Green leaves showed higherphotosynthetic capacity in low light than golden leaves, but golden leaves presented unexpectedly stronger photosyntheticcapacity and lower reactive oxygen species accumulation under the high-light condition. Furthermore, golden leaves showeda higher level of nonphotochemical quenching (NPQ) after the light-to-dark shift and presented a stronger adaptive abilityto a broad range of light environments. Higher NPQ values and less oxidative damage in golden leaves may be correlatedwith their higher carotenoid levels. The results imply that lower chlorophyll levels and higher carotenoid levels in canopyleaves may help privet plants acclimate better to illumination changes. This study demonstrates the key role of irradiance ingenerating the two types of Ligustrum × vicaryi leaves and sheds a light on cultivation of other ornamental foliage plants.

A predicting model for thermal conductivity of high permeability-high strength concrete materials

Tan, Yi-Zhong,Liu, Yuan-Xue,Wang, Pei-Yong,Zhang, Yu Techno-Press 2016 Geomechanics & engineering Vol.10 No.1

The high permeability-high strength concrete belongs to the typical of porous materials. It is mainly used in underground engineering for cold area, it can act the role of heat preservation, also to be the bailing and buffer layer. In order to establish a suitable model to predict the thermal conductivity and directly applied for engineering, according to the structure characteristics, the thermal conductivity predicting model was built by resistance network model of parallel three-phase medium. For the selected geometric and physical cell model, the thermal conductivity forecast model can be set up with aggregate particle size and mixture ratio directly. Comparing with the experimental data and classic model, the prediction model could reflect the mixture ratio intuitively. When the experimental and calculating data are contrasted, the value of experiment is slightly higher than predicting, and the average relative error is about 6.6%. If the material can be used in underground engineering instead by the commonly insulation material, it can achieve the basic requirements to be the heat insulation material as well.

Morphological and Molecular Phylogenetic Data of the Chinese Medicinal Fungus Cordyceps liangshanensis Reveal Its New Systematic Position in the Family Ophiocordycipitaceae

( Yao Wang ),( Yong-dong Dai ),( Zhong-lin Yang ),( Rui Guo ),( Yuan-bing Wang ),( Zhu L. Yang ),( Lei Ding ),( Hong Yu ) 한국균학회 2021 Mycobiology Vol.49 No.4

A cordycipitoid fungus infecting Hepialidae sp. in Nepal was supposed to be identical to Cordyceps liangshanensis, originally described from southwestern China, and thus, transferred to the genus Metacordyceps or Papiliomyces in previous studies. However, our multi-gene (nrSSU-nrLSU-tef-1a-rpb1-rpb2) phylogenetic and morphological studies based on the type specimen and additional collections of C. liangshanensis revealed that the fungus belongs to the genus Ophiocordyceps (Ophiocordycipitaceae). Therefore, a new combination O. liangshanensis was made, and a detailed description of this species was provided.

Design strategies of supported metal-based catalysts for efficient oxidative desulfurization of fuel

Lei Chen,Zhong-Yong Yuan 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.108 No.-

The consumption of fuel oil containing sulfur compounds produces SOx, which inevitably leads to severeenvironmental pollution and even threatens human health. Oxidative desulfurization (ODS) has beenidentified as a promising pathway to produce clean fuel by virtue of its high efficiency and mild reactionconditions. In recent years, supported metal-based catalysts have attracted scientific research interestdue to the high activity and remarkable recyclability for ultra-deep ODS reactions. In this review, the latestresearch progress on the supported metal-based ODS catalysts is summarized. The reaction mechanismof the supported metal-based ODS catalysts is briefly discussed based on the different metalactive components. Notably, we focus on summarizing the design strategies of highly efficient supportedmetal-based ODS catalysts, with special emphasis on the creation of the concentrated microenvironmentof reactants around active sites, construction of highly effective catalytically active sites and improvementof recyclability. These improved strategies are also applicable to the development of the supportedmetal-based catalysts for other green catalytic reactions. In addition, the current issues and future developmenttrends of the supported metal-based ODS catalysts are pointed out.

Orthogonal 방법을 통한 Poly(AM-DMDAAC)/MMT 고흡수성나노복합체 제조 연구

Jun Dong Yuan,Ming Zhou,Shuang Qiao Yang,Yong Guo Zhou,Nan Qin,Song Tao He,Dong Lai,Zhong Qiang Xie 한국고분자학회 2014 폴리머 Vol.38 No.1

A novel poly(AM-DMDAAC)/MMT superabsorbent nanocomposites are prepared by radical polymerizationusing ammonium persulfate (APS) and anhydrous sodium sulfite as a free radical initiator and N,N-methylene bisacrylamide(MBA) as a crosslinker. In this paper, an optimization study on the synthesis of superabsorbent nanocompositesis carried out. Orthogonal array experiment indicates that the optimized conditions is acrylamide (AM) content 23 wt%,diallyl dimethyl ammonium chloride (DMDAAAC) content 6 wt%, montmorillonite (MMT) content 4 wt%, initiatorcontent 0.2 wt% and crosslinker content 0.02 wt%. Under the optimization syntheses conditions concluded, the maximumwater absorbency in distilled water is 659.53 g·g-1 and in 2 wt% sodium chloride solution is 116.25 g·g-1. Compared withthe range values of different factors (Rj), the order of significance factors in distilled water is C (MMT) > B (DMDAAC)> A (AM) > D (crosslinker) > E (initiator). MMT is intercalated during polymerization reaction and a nanocompositestructure is formed as shown by TEM analysis and XRD analysis.

Recent advances in transition metal layered double hydroxide based materials as efficient electrocatalysts

Yi Feng,Lei Chen,Zhong-Yong Yuan 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.120 No.-

The development of efficient electrocatalysts occupies a vital position in achieving efficient energy conversionand storage. Transition-metal-based layered double hydroxides (TM LDHs) featuring unique layeredstructure have received extensive attention in the field of designing highly cost-effectiveelectrocatalysts. Nevertheless, the practical application of TM LDH-based electrocatalysts still faces a seriesof challenges including insufficient active sites, inferior intrinsic conductivity and suboptimal robustness. Throughout this review, the most recent researches dedicated to TM LDH-based electrocatalysts arereviewed in terms of structural features, synthetic strategies, modification approaches and electrocatalyticapplications. This review focuses on the effective modification approaches and important electrochemicalapplications of TM LDHs. This review supplies the conducive tools to select the appropriatetechnics for adequately boosting the electrocatalytic performance of TM LDH-based electrocatalystsand concludes with a salient summary outlining orientations for further research.