An Improved H.264 Encoded Algorithm Based on Weber-Fechner Law

Yanhui Xia,Baisheng Nie,Zhengyou Wang,Liying Li,Jianhua Ming,Zheng Wan,Shuying Huang 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.9

With the study of human visual system (HVS), people find that the human eye shows different degree of sensitivity to different light signals. A higher background brightness region of the human eye for the distortion, the degree of sensitivity will be greatly reduced. The human eye’s sensitivity will be greatly reduced to the distortion of a higher brightness background region. This finding is discribed in Weber-Fechner law. Therefore, the encoder can be improved by employing this characteristic of human visual system. In this paper, the authors use this characteristic to improve the H.264 video coding algorithm. In order to improve the compression efficiency of encoder, give the brightness of different regions with different levels of quantification by adjusting the quantization step size (QP), without affecting the subjective quality of video. Experimental results show that the output bit rate decrease up to 10% -20% by using this improved algorithm in H.264 reference encoder, and the subjective quality of decoded image by using this improved algorithm is as good as the standard H.264 encoders.

Web-Based Collaborative Learning System and Its Key Techniques

Yanhui Xia,Zhengyou Wang,Yi Li,Jinfeng Hu 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.12

On the basis of concept, characteristics and related work of collaborative learning, this paper proposes an intelligent web collaborative learning system prototype based on multi-agent technology. At first, the paper introduces a collaborative learning framework which supporting group learning and illustrates the whole learning process. Secondly, the paper presents some key issues to implementation of the virtual learning environment, such as intelligent grouping, automatic question answering, knowledge management, and opinion mining. Preliminary learning practice shows that it is a practical and efficient way.

Effects of Envy on Depression: The Mediating Roles of Psychological Resilience and Social Support

Xiang Yanhui,Dong Xia,Zhao Jiaxu 대한신경정신의학회 2020 PSYCHIATRY INVESTIGATION Vol.17 No.6

Objective Envy, as a stable personality trait, can affect individuals’ mental health. Specifically, previous studies have found that envy can lead to depression; however, the mechanism by which envy affects depression is still unclear. Therefore, based on the resilience framework, we used structural equation modeling to explore the mediating roles that social support and psychological resilience play between envy and depression.Methods Chinese college students (n=680) were recruited to complete four scales: the Dispositional Envy Scale (DES), the Symptom Checklist 90-Depression Subscale (SCL-90-DS), the Connor-Davidson Resilience Scale (CD-RISC), and the Perceived Social Support Scale (PSSS).Results The results confirmed that both social support and psychological resilience are significant mediators between envy and depression. Furthermore, social support plays a significant mediating role between envy and psychological resilience, and psychological resilience plays a significant mediating role between social support and depression. Specifically, the results indicated that envy not only directly increases the likelihood of developing depression, but also indirectly increases the likelihood of developing depression by affecting psychological resilience through negatively influencing social support.Conclusion This study provides a theoretical basis for enhancing psychological resilience and social support in order to ameliorate adverse effects of envy on depression.

Anatomical Observations of Adventitious Bud Regeneration from Leaf Explants of Ziziphus jujube Mill. ‘Huizao’

Chunhua Ma,Xia Ye,Yanhui Chen,Jiancan Feng,Xiaoli Shang,Jidong Li,Yingxia Wu,Jianbin Hu 한국원예학회 2012 Horticulture, Environment, and Biotechnology Vol.53 No.4

The histological process of adventitious shoot regeneration from the leaf explants of Zizyphus jujuba ‘Huizao’was reported in this study. This is the first report on the detailed histological process of direct shoot regeneration from leaf explants in Z. jujube. Shoot regeneration was obtained from woody plant medium (WPM) supplemented with 2.27 μM thidiazuron (TDZ), 1.07 μM α-naphthalene-acetic acid (NAA) and 2.94 μM silver nitrate (AgNO3) for 10days in the dark followed by 3 weeks at a 14 hours photoperiod. The adventitious buds mostly formed from leaf veins and petioles, and the further histological studies revealed that there were multiple vascular bundles around leaf veins and the adaxial side of explants, and the adventitious buds directly originated from the parenchymatous cells around the vascular bundles without the intervening callus phase. After 3 days of culture, the parenchymatous cells started dividing and meristemoids formed thereafter. The meristematic cells continued division and subsequently gave rise to bud primordia. Well-developed shoot buds through direct organogenesis was achieved after 20 days of culture.

Tensile Properties and Corrosion Behavior of a Dilute Mg–0.5Sn–0.7Al–0.8Zn Alloy Applied for Biomaterials

Weili Cheng,Yanhui Liu,Yao Zhang,Shuaiju Meng,Srinivasan Arthanari,Hong‑xia Wang,Lifei Wang 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.11

A novel dilute Mg–0.5Sn–0.7Al–0.8Zn alloy was developed and directly extruded after casting process. The extrudedalloy consisted of fine bimodal grained microstructure, local nano-precipitates micro-region and typical extrusion direction(ED)-tilted texture. A great balance between tensile properties (YS = 262.7 MPa, EL = 26.0%) and corrosion resistance(Pi = 1.57 mm/a) was achieved and discussed in terms of grain size, structure, orientation as well as precipitates and/or corrosionproduct film. As a result, this dilute alloy system shows the great potential to be developed as a biomaterial.

Realizing Rationally-Balanced Dielectric Properties in Fluoropolymer/Cr2AlC MAX Composites Modified by 2D-BN

Qin Li,Junquan Zhou,Yanhui Chen,Xiaofeng Xia,Maolin Bo,Qihuang Deng,Yefeng Feng 한국고분자학회 2020 Macromolecular Research Vol.28 No.13

Polymer/conductor composite dielectric materials have a high dielectric constant. In recent years, composite dielectrics have become a study hotspot in highdensity energy storage capacitors. However, high dielectric loss and high electrical conductivity make the application of the composite materials very limited. In order to obtain composite materials with high dielectric constant, low dielectric loss and low conductivity, we added the insulating boron nitride (BN) filler into polymer/Cr2AlC composites. As a conductive filler, Cr2AlC ternary-layered-compound (MAX) ceramic has an interface polarization with the polymer matrix, thereby increasing the dielectric constant of the composites. The insulating BN has a very low electrical conductivity, which can effectively reduce the electrical conductivity and dielectric loss of the composites. Compared with the binary polymer/Cr2AlC composite materials, the ternary polymer/Cr2AlC/BN composite materials can achieve the low dielectric loss and low conductivity as well as properly-lowered dielectric constant. The ternary composite material filled with 10 wt% Cr2AlC and 2 wt% BN has a dielectric constant of about 30, a dielectric loss of about 0.7 and a conductivity of about 4.6×10- 7 S m-1 at 100 Hz. In this work, high-performance composite dielectrics were prepared through good cooperation between conductive and insulating ceramic fillers, which might provide an idea for design of promising energy storage capacitors.

A New Image Quality Assessment Algorithm based on SSIM and Multiple Regressions

Zhengyou Wang,Liying Li,Shuang Wu,Yanhui Xia,Zheng Wan,Cong Cai 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.11

Image quality assessment (IQA) is crucial in image processing algorithms. In the state-of-the-art IQA index, the structural similarity (SSIM) index has been proved to be better objective quality assessment metric. However, the accuracy of SSIM is relatively lacking when used to access blurred images. And the component weights of structural similarity (SSIM) index are fixed in some past environments. So an improved assessment algorithm incorporating multiple linear regressions and SSIM index was proposed in this paper. We use regression analysis to adjust the component weight of SSIM index. So the improved algorithm is more accuracy on different distortion types’ quality assessment. Experimental results show that the improved SSIM algorithm is better than traditional methods in nonlinear regression correlation coefficient, Spearman correlation coefficient and out ratio.

Enhanced Ultra‑violet Photodetection Based on a Heterojunction Consisted of ZnO Nanowires and Single‑Layer Graphene on Silicon Substrate

Yu Liu,Zengcai Song,Sheng Yuan,Lei Xu,Yanhui Xin,Meixia Duan,Shuxia Yao,Yangrui Yang,Zhenwei Xia 대한금속·재료학회 2020 ELECTRONIC MATERIALS LETTERS Vol.16 No.1

In this study, heterojunction photoelectric devices based ZnO nanowires were fabricated on p-Si substrate with and without single-layer graphene as insert layer. ZnO nanowires and graphene were prepared by hydrothermal method and chemical vapor deposition respectively. The efect of insert layer on the morphology of ZnO nanowires was very weak as can be seen from scanning electron microscope and X-ray difraction. Raman scattering showed that the graphene prepared was a singlelayer structure. The ultraviolet detection performance of photodetectors with single graphene insert layer was much better than that of photodetectors without single graphene insert layer. The ultraviolet irradiation sensitivity of photodetectors with single graphene insert layer was up to 1071 which was improved 7 times than that of photodetectors without single graphene insert layer. Moreover, photodetectors with single graphene insert layer had faster response time (1.02 s) and recovery time (0.34 s).