A New Dynamic Transmission-Mode Selection Scheme for AMC/HARQ-Based Wireless Networks

( Xiaohui Ma ),( Guobing Li ),( Guomei Zhang ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.11

In this paper, we study the cross-layer design for the AMC/HARQ-based wireless networks, and propose a new dynamic transmission-mode selection scheme to improve system spectrum efficiency. In the proposed scheme, dynamic thresholds for transmission-mode selection in each packet transmission and retransmission are jointly designed under the constraint of the overall packet error rate. Comparing with the existing schemes, the proposed scheme is inclined to apply higher modulation order at the first several (re)transmissions, which corresponds to higher-rate transmission modes thus higher average system spectrum efficiency. We also extend the cross-layer design to MIMO (Multi-input Multi-output) communication scenarios. Numerical results show that the proposed new dynamic transmission-mode selection scheme generally achieves higher average spectrum efficiency than the conventional and existing cross-layer design.

Two-Dimensional SPH Analysis of Seepage with Water Injection Process for Different Crack Morphologies

Haichun Ma,Jingping Wang,Jiazhong Qian,Xiaohui Tan,Luwang Chen,Yaping Deng,Zhitang Lu,Lei Ma 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.5

Crack seepage in nature involves natural and water injection flow, causing crack morphology in nature to be varied. Using the numerical simulation method of smoothed particle hydrodynamics (SPH), the natural free flow process in a crack was analyzed. With the interference of the initial velocity of the x = 0 particles, the other terminal particles were shifted, and the particles with initial velocities were reversed. For water injection simulations, ghost particles were set to block particles from overflowing, as particles subjected to injection water were mobilized more quickly than under free flow conditions. For rough cracks, particle magnitude was affected by the boundary shape, but overall particle velocity was influenced little, and the distribution of particles was sparse and densely spaced. For the branch crack simulation, overall particle seepage velocity decreased, but particles moved faster through the wider branch than through the narrower branch. SPH can simulate the seepage through crack networks and be used to analyze the effects of different crack geometries and physical properties.

Current Review on the Research Status of Cemented Carbide Brazing: Filler Materials and Mechanical Properties

Xiaohui Yin,Qunshuang Ma,Bing Cui,Lei Zhang,Xingyan Xue,Sujuan Zhong,Dong Xu 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.4

Cemented carbides have been widely applied in cutting tools and wear-resistant components due to their ultrahigh hardnessand good wear resistance. However, the disadvantages of limited impact toughness and high cost have restricted their furtherapplication. Consequently, cemented carbides are usually joining with ductile steels to combine the advantages of both. Among various materials joining technologies, brazing have been an effective method to achieve high quality dissimilarcemented carbide joints. In this paper, the research status of cemented carbide brazing is reviewed. The materials utilized asbrazing filler metal in cemented carbide brazing joints are summarized in detail. Researchers have done lots of works utilizingCu based and Ag based brazing filler metals which are the most commonly used interlayers in brazed joints of cementedcarbide and ductile steel. The effects of different filler metal on wettability, microstructure, phase constitution and mechanicalproperties of brazed cemented carbides joints are analysed. Besides, a series of newly developed brazing filler materialsuch as nickel-based high temperature brazing filler metal, amorphous brazing filler metal and high entropy alloy brazingfiller materials are also involved. These newly developed brazing filler metals have shown great potential in fabricating highquality joints. Finally, the current issues of cemented carbide brazing are reviewed and the develop trend is predicted.

Compressive Properties of High-distance Warp-knitted Spacer Flexible Composite

Xiaohui Zhang,Yuanyuan Yu,Andrews Boakye,Pibo Ma 한국섬유공학회 2018 Fibers and polymers Vol.19 No.5

This paper mainly introduces a high-distance warp-knitted spacer flexible composite material which is a special material consisting of high-distance warp-knitted spacer fabric and some coating materials. It introduces the designing process as well as the preparation of high-distance warp-knitted flexible composite material. In order to comprehend the influence of internal pressure on the material, the mechanical properties under 100 %, 80 % and 60 % gas pressure have been explored. A compression test under these three kinds of gas pressure was carried out and the related force displacement diagram, the stress-strain curve and the energy strain curve which directly reflects the variation of the mechanical properties of the composites material under the different gas pressure were obtained and presented. A deep investigation and analysis was conducted into knowing the compressive properties of the material and how they are affected by the gas pressure. The experimental results obtained shows that the compressive properties of the high-distance warp-knitted space flexible material is dependent on the amount of gas inserted. Again the compressive strength of the material keeps growing stronger with an increase in the intensity of the gas pressure.

Separation and Characterization of Organic Chlorides in a Chinese Crude Oil

Xiaohui Li,Rui Ma,Liang Ding,Huiying Yuan,Bencheng Wu,Jianhua Zhu 대한화학회 2018 Bulletin of the Korean Chemical Society Vol.39 No.4

A crude oil from Shengli oilfield of China was extracted with N,N‐dimethylformamide (DMF) for separation and enrichment of organic chlorides. The resulting extract with relatively higher chlorine concentration was analyzed with gas chromatography–mass spectrometry (GC/MS). Among the identified heteroatom compounds in the extract sample, nitrogen‐containing compounds were most abundant in the extract sample, followed by chlorine‐, sulfur‐, and oxygen‐containing compounds, respectively. Four organochlorines with an aromatic core structure, i.e., 5‐chloro‐2‐methylaniline, 2‐chloro‐6‐methylaniline, 4‐chloro‐2‐nitrotoluene, and 1‐(5‐chloro‐2‐hydroxyphenyl)ethanone, were identified from crude oil extract. The dominant abundant organic chloride is 5‐chloro‐2‐methylaniline with relative content of 65.1% in the total of identified organic chlorides, followed by 1‐(5‐chloro‐2‐hydroxyphenyl)ethanone of 16.3%, 2‐chloro‐6‐methylaniline of 14.5%, and 4‐chloro‐2‐nitrotoluene of 4.1%, respectively.

The Effect of Adapted Aquatic Activity for Children with Cerebral Palsy in School Age

( Xiaohui Hou ),( Yanqing Fen ),( Zeming Ma ),( Hanjing ),( Yuedan Wu ),( Xiaodong Tian ) 한국체육학회 2015 국제스포츠과학 학술대회 Vol.2015 No.1

Objective: To observe the effect of adapted aquatic activity in the role of rehabilitation for children with cerebral palsy in school age. Methods: Twenty-four spastic cerebral palsy children of Guangzhou Cerebral Palsy Rehabilitation School were selected as subjects. These subjects were divided into the control group (regular rehabilitation therapy, RRT, n=12) and the experimental group (regular rehabilitation plus adapted aquatic activity with Halliwick technique, APA n=12). GMFM-88, the Berg balance scale, BMI and sit and reach were measured before and after the treatment. Results: After treatment, GMFM-88 total scores, Berg Balance Scale scores ,Lung`s capacity, sit and reach of APA group increased significantly than before, P<0.05. The RRT group increased too, but the difference was not significant. Half of experiment group can swimming 50-100m independently after 4 months training. There was no significant difference of BMI, sit and reach,GMFM-88 total scores, Berg Balance Scale scores between two groups after treatment (P>0.05), except lung`s capacity of APA group was significant higher than the control group (P < 0.05). Conclusion: Halliwick technical is an effective method to guide APA for school-aged children with cerebral palsy. APA can effectively enhance the gross motor function, balance, flexibility and respiratory capacity and it could be an effective method with other method for school-aged children with cerebral palsy to achieve life-long sport and rehabilitation. But how long to achieve significant effect still need to more research.

A Novel Power Transformer Fault Diagnosis Model Based on Harris-Hawks-Optimization Algorithm Optimized Kernel Extreme Learning Machine

Han Xiaohui,Ma Shifeng,Shi Zhewen,An Guoqing,Du Zhenbin,Zhao Chunlin 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.3

Dissolved gas analysis (DGA) method is widely used to detect the incipient fault of power transformers. This paper presents a novel DGA method for power transformer fault diagnosis based on Harris-Hawks-optimization (HHO) algorithm optimized kernel extreme learning machine (KELM). The non-code ratios of the gases are used as the characterizing vector for the KELM model, and the Harris-Hawks-optimization (HHO) algorithm is introduced to optimize the KELM parameters, which promotes the fault diagnostic performance of KELM. Based on dataset collected from IEC TC 10, the fault diagnosis capability of the proposed method is validated by different characterizing vectors and is compared with conventional KELM and other optimized KELM. Moreover, the generalization ability of the proposed method is confirmed by China DGA data. The results demonstrate that the proposed method is superior to other methods and is more effective and stable for power transformer fault diagnosis with high accuracy.

Engineered fibrotic liver-targeted truncated transforming growth factor β receptor type II variant for superior anti-liver fibrosis therapy

Manman Ma,Xiaohua Wang,Xiaohui Liu,Yang Han,Yanhui Chu,Yanzhong Guan,Haifeng Liu 대한약학회 2023 Archives of Pharmacal Research Vol.46 No.3

Truncated transforming growth factor β receptor type II (tTβRII) is a promising anti-liver fibrotic candidate because it serves as a trap for binding excessive TGF-β1 by means of competing with wild type TβRII (wtTβRII). However, the widespread application of tTβRII for the treatment of liver fibrosis has been limited by its poor fibrotic liver-homing capacity. Herein, we designed a novel tTβRII variant Z-tTβRII by fusing the platelet-derived growth factor β receptor (PDGFβR)-specific affibody ZPDGFβR to the N-terminus of tTβRII. The target protein Z-tTβRII was produced using Escherichia coli expression system. In vitro and in vivo studies showed that Z-tTβRII has a superior specific fibrotic liver-targeting potential via the engagement of PDGFβR-overexpressing activated hepatic stellate cells (aHSCs) in liver fibrosis. Moreover, Z-tTβRII significantly inhibited cell migration and invasion, and downregulated fibrosis- and TGF-β1/Smad pathway-related protein levels in TGF-β1-stimiluated HSC-T6 cells. Furthermore, Z-tTβRII remarkably ameliorated liver histopathology, mitigated the fibrosis responses and blocked TGF-β1/Smad signaling pathway in CCl4-induced liver fibrotic mice. More importantly, Z-tTβRII exhibits a higher fibrotic liver-targeting potential and stronger anti-fibrotic effects than either its parent tTβRII or former variant BiPPB-tTβRII (PDGFβR-binding peptide BiPPB modified tTβRII). In addition, Z-tTβRII shows no significant sign of potential side effects in other vital organs in liver fibrotic mice. Taken together, we conclude that Z-tTβRII with its a high fibrotic liver-homing potential, holds a superior anti-fibrotic activity in liver fibrosis in vitro and in vivo, which may be a potential candidate for targeted therapy for liver fibrosis.

Illumina-sequencing based transcriptome study of coat color phenotypes in domestic goats

Yongdong Peng,Xiaohui Liu,Liying Geng,Ruxue Ma,Lisha Li,Jingshi Li,Chuansheng Zhang,Zhengzhu Liu,Yuanfang Gong,Xianglong Li 한국유전학회 2017 Genes & Genomics Vol.39 No.8

This study performed a comprehensive expression profiling of genes expressed in the skin of goats with three different coat colors by Illumina Sequencing. A total of 91 significantly expressed genes were detected when comparing gray skin to white skin library and these included 74 up-regulated and 17 down-regulated genes in gray skin. There were 67 differentially expressed genes between brown skin and white skin libraries, 23 of which were up-regulated and 44 were down-regulated in brown skin. When we compared brown and gray libraries, 154 differentially expressed genes were found, of which 33 showed higher expression and 121 showed lower expression in brown skin. To our surprise, MC1R, MITF, TYR and KIT showed no significant difference in expression between the goats with three skin colors, whereas ASIP was detected in white skin but not in dark skins. In this study, PMEL, TRPM1, TYRP1 and DCT were significantly upregulated in brown goat skin compare with gray and white skins. PMEL showed higher expression in gray goat skin compared with white goat skin, whereas there were no significant differences in the expression of TYRP1, TRPM1 and DCT between gray and white skin samples. In addition, ELOVL3 showed higher expression in gray goat skin than in brown and white skins, whereas there was no significant differences in the expression of ELOVL3 between brown and white skin samples. These results expand our understanding of the complex molecular mechanisms of skin physiology and melanogenesis in goat and provide a foundation for future studies.

An Experimental Study on Seepage within Shale Fractures due to Confining Pressure and Temperature

Jingping Wang,Haichun Ma,Peichao Feng,Qing Zhang,Jiazhong Qian,Xiaohui Tan,Lei Ma,Daoxiang Wu 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.9

Seepage of groundwater within rock fractures is widespread. The seepage conditions in the fractures can be affected by the stress and temperature conditions. Shale seepage conditions are a complicated coupling of stress and temperature. Experiments were carried out on shale samples containing three types of fractures: a single short fracture (type A), a single long fracture (type B), and symmetrical short fractures (type C). Three temperature conditions were set for type A. The coefficient C, which is defined as the ratio between the seepage pressure and the flow rate, is constant when the temperature effects are slight. Linear correlations between the coefficient C and the temperature were simulated. For type B, four confining pressures were applied using the confining pressure pump. As the confining pressure increases, the seepage pressure increases. The seepage pressure distribution is nonlinear when the flow rate increases to 6 ml/min under a confining pressure of 12 MPa. For type C, three temperature conditions with three confining pressure conditions were analyzed to determine the seepage pressure. The effects of the confining pressure on the seepage pressure are different from those of type B. Nonlinear curves occur under confining pressures of 3 MPa and 6 MPa at 50°C. The seepage pressure values at 70°C are smaller than those at 30°C and 50°C. The coefficient C contour is depicted for the experimental ranges of temperature and confining pressures. The small value region of coefficient C occurs at about 6 MPa and 50°C. The nonlinear increase in the seepage pressure in the fractures occurred when the confining pressure was larger for a single fracture and when the confining pressure was lower for double fractures.