Test for the covariance matrix in time-varying coefficients panel data models with fixed effects

Yuping Hu,Sanying Feng,Jing Zhao 한국통계학회 2021 Journal of the Korean Statistical Society Vol.50 No.2

This paper proposes tests for the null of sphericity and identity matrix for nonparametric time-varying coefficient panel data models with fixed effects. Firstly, based on the local linear smoothing technique, the estimators of the unknown coefficient functions and model residuals are obtained. Secondly, proper test statistics are proposed aiming at tests for sphericity or identity matrix with a large number of cross sectional units and time series observations. In addition, the limiting distributions of the proposed test statistics are derived based on random matrix theory. At last, some simulation studies are conducted to examine the finite sample performance for the proposed test statistics and a real data example is analyzed.

A Novel Image Encryption Scheme based on the LSM Chaotic System

Congxu Zhu,Yuping Hu,Xinran Zhou 보안공학연구지원센터 2014 International Journal of Security and Its Applicat Vol.8 No.6

The Logistic-Sine map (LSM) chaotic system is introduced by combing the Logistic map (LM) and Sin map (SM). The bifurcation diagrams show that the chaotic range of LSM is much larger than these of the Logistic or Tent maps. Complexity characteristics of Logistic map, Sine map and Logistic-Sine map are analyzed based on C0 algorithm. The results show that C0 complexity value of the LSM is the largest one among the three. Then, a novel image encryption scheme based on the LSM chaotic system was proposed. First, the positions of image pixels are shuffled through swapping positions randomly by using chaotic values. The permutation sequences are ralated to plain-images by introducing the plaintext feedback technique. Second, the diffusion procedure with LSM is introduced to diffuse the image, which is composed of two rounds. The experimental results and analysis by using several security measures show that the proposed image encryption scheme has high security and efficiency.

Study of Deflection Routing from an Information-theoretic Perspective

Xinwei Zheng,Yuping Hu,Dongjun Luo,Xiaoyun Wu 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.1

Deflection routing is an effective way to improve the efficiency and reliability of data transmission in the network. Information theory, which is the foundation of channel communications, has not yet had a direct impact on network communications. In this paper, we study the deflection routing processes of point-to-point networks from an information-theoretic perspective. It is found that the packet routing processes, which can further be divided into path determination and path switching, are quite analogous to channel communications. And such a corresponding relationship makes it possible to analyze routing processes and its performance with models and concepts in the information theory.

OOAP : A Novel Authorization Protocol for Access to Sensitive Data in Trusted Cloud Computing Platforms

Dongjun Luo,Xiaoyun Wu,Xinwei Zheng,Yuping Hu 보안공학연구지원센터 2014 International Journal of Security and Its Applicat Vol.8 No.6

Cloud computing platforms are usually constructed as trusted virtual platforms based on trusted computing technologies. This is one of the most effective approaches to resolve cloud computing security problems. However, the protection of sensitive data in trusted virtual platforms is an important problem needed to be resolved. In this paper, we proposed a novel authorization protocol. The protocol assembled the functions of OIAP, OSAP and AACP protocols, and prevented all known attacks in existing authorization protocols. Moreover, it satisfied the property of exclusivity and was compatible with TCG TPM command formats. The protocol effectively protects the sensitive data from unauthorized accesses in trusted cloud computing platforms.

Artificial Ground Freezing In Tunnelling Through Aquifer Soil Layers: a Case Study in Nanjing Metro Line 2

Jun Hu,Yong Liu,Yuping Li,Kai Yao 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.10

In this paper, the construction of a section of Nanjing Metro Line 2, a shallow underground tunnel constructed with an underground mining method, was analysed. Due to the existence of two aquifer soil layers near the tunnel, water and sand inrush occurred during the tunnelling process. This disrupted tunnelling project was covered until the artificial ground freezing technique was used to achieve a waterless environment. After the 40-day active freezing period, the ground temperature conditions satisfied the design requirements, thereby ensuring the construction schedule. The ground freezing technique and other supplementary measurements were introduced in this study, which could be useful for other similar projects.

Smooth-threshold GEE variable selection for varying coefficient partially linear models with longitudinal data

Ruiqin Tian,Liugen Xue,Yuping Hu 한국통계학회 2015 Journal of the Korean Statistical Society Vol.44 No.3

In this paper, we consider the problem of variable selection for varying coefficient partially linear models with longitudinal data. A new variable selection procedure is proposed based on smooth-threshold generalized estimating equation (SGEE). The proposed procedure simultaneously selects significant variables in the parametric components and the nonparametric components. The approach avoids the convex optimization problem and is flexible and easy to implement. The consistency and asymptotic normality of the resulting estimators are established. Extensive Monte Carlo simulation studies are conducted to examine the finite sample performance of the proposed variable selection procedure. The proposed procedure is further illustrated by an application.

Gene expression and promoter methylation of porcine uncoupling protein 3 gene

Ruiyi Lin,Weimin Lin,Qiaohui Chen,Jianchao Huo,Yuping Hu,Junxiao Ye,Jingya Xu,Tianfang Xiao 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.2

Objective: Uncoupling protein 3 gene (UCP3) is a candidate gene associated with the meat quality of pigs. The aim of this study was to explore the regulation mechanism of UCP3 expression and provide a theoretical basis for the research of the function of porcine UCP3 gene in meat quality. Methods: Bisulfite sequencing polymerase chain reaction (PCR) and quantitative real-time PCR (Q-PCR) were used to analyze the methylation of UCP3 5′-flanking region and UCP3 mRNA expression in the adipose tissue or skeletal muscle of three pig breeds at different ages (1, 90, 210-day-old Putian Black pig; 90-day-old Duroc; and 90-day-old Dupu). Results: Results showed that two cytosine-guanine dinucleotide (CpG) islands are present in the promoter region of porcine UCP3 gene. The second CpG island located in the core promoter region contained 9 CpG sites. The methylation level of CpG island 2 was lower in the adipose tissue and skeletal muscle of 90-day-old Putian Black pigs compared with 1-day-old and 210-day-old Putian Black pigs, and the difference also existed in the skeletal muscle among the three 90-day-old pig breeds. Furthermore, the obvious changing difference of UCP3 mRNA expression was observed in the skeletal muscle of different groups. However, the difference of methylation status and expression level of UCP3 gene was not significant in the adipose tissue. Conclusion: Our data indicate that UCP3 mRNA expression level was associated with the methylation status of UCP3 promoter in the skeletal muscle of pigs.

Genetic architecture and candidate genes detected for chicken internal organ weight with a 600 K single nucleotide polymorphism array

Taocun Dou,Manman Shen,Meng Ma,Liang Qu,Yongfeng Li,Yuping Hu,Jian Lu,Jun Guo,Xingguo Wang,Kehua Wang 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.3

Objective: Internal organs indirectly affect economic performance and well-being of animals. Study of internal organs during later layer period will allow full utilization of layer hens. Hence, we conducted a genome-wide association study (GWAS) to identify potential quantitative trait loci or genes that potentially contribute to internal organ weight. Methods: A total of 1,512 chickens originating from White Leghorn and Dongxiang Blue-Shelled chickens were genotyped using high-density Affymetrix 600 K single nucleotide polymorphism (SNP) array. We conducted a GWAS, linkage disequilibrium analysis, and heritability estimated based on SNP information by using GEMMA, Haploview and GCTA software. Results: Our results displayed that internal organ weights show moderate to high (0.283 to 0.640) heritability. Variance partitioned across chromosomes and chromosome lengths had a linear relationship for liver weight and gizzard weight (R2 = 0.493, 0.753). A total of 23 highly significant SNPs that associated with all internal organ weights were mainly located on Gallus gallus autosome (GGA) 1 and GGA4. Six SNPs on GGA2 affected heart weight. After the final analysis, five top SNPs were in or near genes 5-Hydroxytryptamine receptor 2A, general transcription factor IIF polypeptide 2, WD repeat and FYVE domain containing 2, non-SMC condensin I complex subunit G, and sonic hedgehog, which were considered as candidate genes having a pervasive role in internal organ weights. Conclusion: Our findings provide an understanding of the underlying genetic architecture of internal organs and are beneficial in the selection of chickens.

Genetic evaluation of eggshell color based on additive and dominance models in laying hens

Guo Jun,Wang Kehua,Qu Liang,Dou Taocun,Ma Meng,Shen Manman,Hu Yuping 아세아·태평양축산학회 2020 Animal Bioscience Vol.33 No.8

Objective: Eggshells with a uniform color and intensity are important for egg production because many consumers assess the quality of an egg according to the shell color. In the present study, we evaluated the influence of dominant effects on the variations in eggshell color after 32 weeks in a crossbred population. Methods: This study was conducted using 7,878 eggshell records from 2,626 hens. Heritability was estimated using a univariate animal model, which included inbreeding coefficients as a fixed effect and animal additive genetic, dominant genetic, and residuals as random effects. Genetic correlations were obtained using a bivariate animal model. The optimal diagnostic criteria identified in this study were: L* value (lightness) using a dominance model, and a* (redness), and b* (yellowness) value using an additive model. Results: The estimated heritabilities were 0.65 for shell lightness, 0.42 for redness, and 0.60 for yellowness. The dominance heritability was 0.23 for lightness. The estimated genetic correlations were 0.61 between lightness and redness, –0.84 between lightness and yellowness, and –0.39 between redness and yellowness. Conclusion: These results indicate that dominant genetic effects could help to explain the phenotypic variance in eggshell color, especially based on data from blue-shelled chickens. Considering the dominant genetic variation identified for shell color, this variation should be employed to produce blue eggs for commercial purposes using a planned mating system.