Study on Waterborne Polyurethanes Based on Poly(dimethyl siloxane) and Perfluorinated Polyether

Yang Du,Chao Zhou,Zhihui Yang 한국고분자학회 2015 Macromolecular Research Vol.23 No.9

Methylsiloxane and fluorinated segments were introduced into the polymer backbone of polyurethane by direct reaction of isocyanate with dialcohol terminated perfluoropolyether (E10-H) and poly(dimethyl siloxane) (PDMS). The polyurethane structure was revealed by Fourier transform infrared spectrometer in ATR mode and Xray photoelectron spectroscope. It was found that the silicon and fluorine moieties easily migrated to the surface of material in film-forming process due to their lower energy, so the water contact angle on membrane surface was greatly enhanced (maximum 100.1º), and the hydrophobic property of material was improved. Different degree of phase separation was observed by scanning electron microscope. Increment of PDMS or E10-H content caused the phase separation obviously, but section of PDMS and E10-H modified polyurethane showed that phase separation reduced. The linear dynamic viscoelastic measurements indicated that the dynamic storage modulus of all samples increased with the increment of frequency, and PDMS modified WPU’s grew fastest. The slope of G' vs. G'' showed a decrement, so each sample had a shear thinning behavior. The perfluoropolyether oil was to reduce viscosity of the system.

Robust Fuzzy Varying Coefficient Regression Analysis with Crisp Inputs and Gaussian Fuzzy Output

Yang, Zhihui,Yin, Yunqiang,Chen, Yizeng Korean Institute of Information Scientists and Eng 2013 Journal of Computing Science and Engineering Vol.7 No.4

This study presents a fuzzy varying coefficient regression model after deleting the outliers to improve the feasibility and effectiveness of the fuzzy regression model. The objective of our methodology is to allow the fuzzy regression coefficients to vary with a covariate, and simultaneously avoid the impact of data contaminated by outliers. In this paper, fuzzy regression coefficients are represented by Gaussian fuzzy numbers. We also formulate suitable goodness of fit to evaluate the performance of the proposed methodology. An example is given to demonstrate the effectiveness of our methodology.

Robust Fuzzy Varying Coefficient Regression Analysis with Crisp Inputs and Gaussian Fuzzy Output

Zhihui Yang,Yunqiang Yin 한국정보과학회 2013 Journal of Computing Science and Engineering Vol.7 No.4

This study presents a fuzzy varying coefficient regression model after deleting the outliers to improve the feasibility and effectiveness of the fuzzy regression model. The objective of our methodology is to allow the fuzzy regression coefficients to vary with a covariate, and simultaneously avoid the impact of data contaminated by outliers. In this paper, fuzzy regression coefficients are represented by Gaussian fuzzy numbers. We also formulate suitable goodness of fit to evaluate the performance of the proposed methodology. An example is given to demonstrate the effectiveness of our methodology.

Study on Diurnal Variation of Photosynthesis for Magnolia grandiflora L. and Magnolia denudata Desr

Mohua Yang,Zhihui Li,Youan Liu,Liqun Huang,Yan Yang,Fang Geng 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

Aberrant Effective Connectivity of the Ventral Putamen in Boys With Attention-Deficit/Hyperactivity Disorder

Zhihui Lan,Yunkai Sun,Lei Zhao,Yang Xiao,Changxiao Kuai,Shao-Wei Xue 대한신경정신의학회 2021 PSYCHIATRY INVESTIGATION Vol.18 No.8

Objective The connectivity alterations in the putamen were found in revealing the neural correlates of attention-deficit/hyperactivity disorder (ADHD), but whether the effective connectivity of the putamen is atypical in ADHD remains unclear. Investigating this abnormality contributes to describing the neural circuit of ADHD at the level of macrostructural organization. Methods Data were acquired from thirty-two boys with ADHD and fifty-two matched typically developing controls (TDC) from Peking University (Peking) dataset deposited at the Neuroimaging Informatics Tools and Resources Clearinghouse (NITRC) platform. We examined the effective connectivity of the putamen using Granger causality analysis (GCA) and then determined whether these connections could differentiate ADHD from TDC. Results Compared with TDC, the ADHD group showed decreased effective connectivity from the left ventral rostral putamen (VRP) to left calcarine (CAL), right medial part of the superior frontal gyrus, left orbital part of superior frontal gyrus and left middle occipital gyrus (MOG). Increased effective connectivity from the left inferior occipital gyrus and right lingual gyrus to left VRP was also found in ADHD. The result of the classification accuracy showed that 72.3% of participants were correctly classified using support vector machine. Moreover, GCA values from the left VRP to left CAL and left MOG were significantly correlated with hyper/impulsive scores of patients with ADHD. Conclusion The findings may help extend our understanding of the ADHD-related neural loops.

A GPU-based point kernel gamma dose rate computing code for virtual simulation in radiation-controlled area

Zhihui Xu,Mengkun Li,Bowen Zou,Ming Yang Korean Nuclear Society 2023 Nuclear Engineering and Technology Vol.55 No.6

Virtual reality technology has been widely used in the field of nuclear and radiation safety, dose rate computing in virtual environment is essential for optimizing radiation protection and planning the work in radioactive-controlled area. Because the CPU-based gamma dose rate computing takes up a large amount of time and computing power for voxelization of volumetric radioactive source, it is inefficient and limited in its applied scope. This study is to develop an efficient gamma dose rate computing code and apply into fast virtual simulation. To improve the computing efficiency of the point kernel algorithm in the reference (Li et al., 2020), we design a GPU-based computing framework for taking full advantage of computing power of virtual engine, propose a novel voxelization algorithm of volumetric radioactive source. According to the framework, we develop the GPPK(GPU-based point kernel gamma dose rate computing) code using GPU programming, to realize the fast dose rate computing in virtual world. The test results show that the GPPK code is play and plug for different scenarios of virtual simulation, has a better performance than CPU-based gamma dose rate computing code, especially on the voxelization of three-dimensional (3D) model. The accuracy of dose rates from the proposed method is in the acceptable range.

An iBeacon-based Indoor Positioning Systems for Hospitals

Jingjing Yang,Zhihui Wang,Xiao Zhang 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.7

How to help patients find their departments or wards is an issue that needs to be solved by hospitals urgently. This paper presents an iBeacon-based indoor positioning system for hospitals. It firstly analyzes the advantages of iBeacon compared with the common indoor positioning technologies; then designs the indoor positioning system for hospitals based on the three-layer architecture of Internet of things to have message-push-service through clients. Finally, the shortest distance algorithm Floyd is used to recommend the nearest department or ward to patients. Shown as result of the experiment, indoor positioning for hospitals can be realized by the system.

Voltammetric Sensor for Sudan I Based on Glassy Carbon Electrode Modified by SWCNT/β-Cyclodextrin Conjugate

Yu Cao,Zhihui Fang,Duanguang Yang,Yong Gao,Huaming Li 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2015 NANO Vol.10 No.2

We reported a sensitive voltammetric sensor for Sudan I determination by modifying glassy carbon electrode (GCE) with single-walled carbon nanotubes (SWCNTs)/β-cyclodextrin conjugate. The cyclic voltammetry results showed that the modified GCE exhibited strong catalytic activity toward the electro-reduction of Sudan I with a well-defined cyclic voltammetric peak at -673 mV. Differential pulse voltammetry measurement showed that the response current exhibited a linear range between 50 nM and 5 µM, and the detection limit was as low as 2.22 nM (S/N=3). The enhanced electrochemical performance of the fabricated sensor was attributed to the combination of the excellent electrocatalytic properties of SWCNTs and the molecular recognition ability of β-cyclodextrin to Sudan I. The sensor was successfully applied to determine Sudan I in real food samples with satisfactory results.

Maternal nutrition altered embryonic MYOD1, MYF5, and MYF6 gene expression in genetically fat and lean lines of chickens

Li Feng,Yang Chunxu,Xie Yingjie,Gao Xiang,Zhang Yuanyuan,Ning Hangyi,Liu Guangtao,Chen Zhihui,Shan Anshan 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.8

Objective: The objectives of this study were to evaluate the effects of daily feed intake during the laying period on embryonic myogenic differentiation 1 (MYOD1), myogenic factor 5 (MYF5), and myogenic factor 6 (MYF6) gene expression in genetically fat and lean lines of chickens. Methods: An experiment in a 2×2 factorial design was conducted with two dietary intake levels (100% and 75% of nutrition recommendation) and two broiler chicken lines (fat and lean). Two lines of hens (n = 384 for each line) at 23th week of age were randomly divided into 4 treatments with 12 replicates of 16 birds. The experiment started at 27th week of age (5% egg rate) and ended at 54th week of age. Hatched eggs from the medium laying period were collected. Real time polymerase chain reaction analysis was used to analyse the MYOD1, MYF5, and MYF6 mRNA levels of E7, E9, E11, E13, and E15 body tissues and E17, E19, and E21 chest and thigh muscle samples. Results: The results indicated that there were significant effects of line, dietary intake, and interactions between them on MYOD1, MYF5, and MYF6 gene mRNA expression levels in embryonic tissues. Low daily feed intake did not change the expression trend of MYOD1 mRNA in either line, but changed the peak values, especially in lean line. Low daily feed intake altered the trend in MYF5 mRNA expression level in both lines and apparently delayed its onset. There was no apparent effect of low daily feed intake on the trends of MYF6 mRNA expression levels in either line, but it significantly changed the values on many embryonic days. Conclusion: Maternal nutrient restriction affects myogenesis and is manifested in the expression of embryonic MYOD1, MYF5, and MYF6 genes. Long term selection for fat deposition in broiler chickens changes the pattern and intensity of myogenesis. Objective: The objectives of this study were to evaluate the effects of daily feed intake during the laying period on embryonic myogenic differentiation 1 (<i>MYOD1</i>), myogenic factor 5 (<i>MYF5</i>), and myogenic factor 6 (<i>MYF6</i>) gene expression in genetically fat and lean lines of chickens.Methods: An experiment in a 2×2 factorial design was conducted with two dietary intake levels (100% and 75% of nutrition recommendation) and two broiler chicken lines (fat and lean). Two lines of hens (n = 384 for each line) at 23th week of age were randomly divided into 4 treatments with 12 replicates of 16 birds. The experiment started at 27th week of age (5% egg rate) and ended at 54th week of age. Hatched eggs from the medium laying period were collected. Real time polymerase chain reaction analysis was used to analyse the <i>MYOD1</i>, <i>MYF5</i>, and <i>MYF6</i> mRNA levels of E7, E9, E11, E13, and E15 body tissues and E17, E19, and E21 chest and thigh muscle samples.Results: The results indicated that there were significant effects of line, dietary intake, and interactions between them on <i>MYOD1</i>, <i>MYF5</i>, and <i>MYF6</i> gene mRNA expression levels in embryonic tissues. Low daily feed intake did not change the expression trend of <i>MYOD1</i> mRNA in either line, but changed the peak values, especially in lean line. Low daily feed intake altered the trend in <i>MYF5</i> mRNA expression level in both lines and apparently delayed its onset. There was no apparent effect of low daily feed intake on the trends of <i>MYF6</i> mRNA expression levels in either line, but it significantly changed the values on many embryonic days.Conclusion: Maternal nutrient restriction affects myogenesis and is manifested in the expression of embryonic <i>MYOD1</i>, <i>MYF5</i>, and <i>MYF6</i> genes. Long term selection for fat deposition in broiler chickens changes the pattern and intensity of myogenesis.

Reentry Risk and Safety Assessment of Spacecraft Debris Based on Machine Learning

Hu Gao,Zhihui Li,Depeng Dang,Jingfan Yang,Ning Wang 한국항공우주학회 2024 International Journal of Aeronautical and Space Sc Vol.25 No.1

Uncontrolled spacecraft will disintegrate and generate a large amount of debris in the reentry process. Ablative debris may cause potential risks to the safety of human life and property on the ground. Therefore, predicting the landing points of spacecraft debris and forecasting the degree of risk of waste to human life and property is very important. In view that it is difficult to predict the reentry process and the reentry point in advance, the debris generated from reentry disintegration may cause ground damage for the uncontrolled space vehicle on the expiration of service. In this paper, we adopt the object-oriented approach to consider the spacecraft and its disintegrated components as consisting of simple basic geometric models and introduce three machine learning models: the support vector regression (SVR), decision tree regression (DTR), and multilayer perceptron (MLP) to predict the velocity, longitude, and latitude of spacecraft debris landing points for the first time. Then, we compare the prediction accuracy of the three models. Furthermore, we define the reentry risk and the degree of danger, and we calculate the risk level for each spacecraft debris and make warnings accordingly. The experimental results show that the proposed method can obtain high-accuracy prediction results in at least 10 s and make safety-level warning more real-time.