Color Image Coding Based on Shape-Adaptive All Phase Biorthogonal Transform

( Xiaoyan Wang ),( Chengyou Wang ),( Xiao Zhou ),( Zhiqiang Yang ) 한국정보처리학회 2017 Journal of information processing systems Vol.13 No.1

This paper proposes a color image coding algorithm based on shape-adaptive all phase biorthogonal transform (SA-APBT). This algorithm is implemented through four procedures: color space conversion, image segmentation, shape coding, and texture coding. Region-of-interest (ROI) and background area are obtained by image segmentation. Shape coding uses chain code. The texture coding of the ROI is prior to the background area. SA-APBT and uniform quantization are adopted in texture coding. Compared with the color image coding algorithm based on shape-adaptive discrete cosine transform (SA-DCT) at the same bit rates, experimental results on test color images reveal that the objective quality and subjective effects of the reconstructed images using the proposed algorithm are better, especially at low bit rates. Moreover, the complexity of the proposed algorithm is reduced because of uniform quantization.

Strategic Orientation for Digital Transformation and Firm Performance in Emerging Market Firms : The Mediating Role of Digital Capabilities

Xiaoyan Pan,Shufeng (Simon) Xiao 한국전문경영인학회 2022 한국전문경영인학회 학술대회 발표논문집 Vol.2022 No.05

Prebiotics enhance the biotransformation and bioavailability of ginsenosides in rats by modulating gut microbiota

Xiaoyan Zhang,Sha Chen,Feipeng Duan,An Liu,Shaojing Li,Wen Zhong,Wei Sheng,Jun Chen,Jiang Xu,Shuiming Xiao 고려인삼학회 2021 Journal of Ginseng Research Vol.45 No.2

Background: Gut microbiota mainly function in the biotransformation of primary ginsenosides into bioactive metabolites. Herein, we investigated the effects of three prebiotic fibers by targeting gut microbiota on the metabolism of ginsenoside Rb1 in vivo. Methods: Sprague Dawley rats were administered with ginsenoside Rb1 after a two-week prebiotic intervention of fructooligosaccharide, galactooligosaccharide, and fibersol-2, respectively. Pharmacokinetic analysis of ginsenoside Rb1 and its metabolites was performed, whilst the microbial composition and metabolic function of gut microbiota were examined by 16S rRNA gene amplicon and metagenomic shotgun sequencing. Results: The results showed that peak plasma concentration and area under concentration time curve of ginsenoside Rb1 and its intermediate metabolites, ginsenoside Rd, F2, and compound K (CK), in the prebiotic intervention groups were increased at various degrees compared with those in the control group. Gut microbiota dramatically responded to the prebiotic treatment at both taxonomical and functional levels. The abundance of Prevotella, which possesses potential function to hydrolyze ginsenoside Rb1 into CK, was significantly elevated in the three prebiotic groups (P < 0.05). The gut metagenomic analysis also revealed the functional gene enrichment for terpenoid/polyketide metabolism, glycolysis, gluconeogenesis, propanoate metabolism, etc. Conclusion: These findings imply that prebiotics may selectively promote the proliferation of certain bacterial stains with glycoside hydrolysis capacity, thereby, subsequently improving the biotransformation and bioavailability of primary ginsenosides in vivo.

Improving the thermoelectric properties of carbon nanotubes through introducing graphene nanosprings

Xiaoyan Xu,Huaping Xiao,Tao Ouyang,Jianxin Zhong 한국물리학회 2020 Current Applied Physics Vol.20 No.1

Carbon nanotube (CNT) is a typical one-dimensional nanomaterial containing sp2 hybridization states. In this paper, we investigate the ballistic thermoelectric performance of CNTs incorporating graphene nanosprings by using non-equilibrium Green's function. The calculations reveal that the thermoelectric figure of merit could be obviously improved by introducing graphene nanosprings, which is about ten times of that of pristine CNTs at 700 K. Such enhancement is mainly attributed to the remarkable suppression of phononic and electronic thermal conductance and improvement of Seebeck coefficient. In addition, compared to the zigzag graphene nanospring, introducing of the armchair case possesses better thermoelectric performance. The results presented in this paper indicate that embedding graphene nanospring is a viable method to optimize the thermoelectric performance of CNTs and could provide useful theoretical guidance for design and fabrication of CNTs-based thermoelectric devices

A Mononuclear Nonheme Iron(IV)-Amido Complex Relevant for the Compound II Chemistry of Cytochrome P450

Lu, Xiaoyan,Li, Xiao-Xi,Seo, Mi Sook,Lee, Yong-Min,Clé,mancey, Martin,Maldivi, Pascale,Latour, Jean-Marc,Sarangi, Ritimukta,Fukuzumi, Shunichi,Nam, Wonwoo American Chemical Society 2019 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.141 No.1

<P>A mononuclear nonheme iron(IV)-amido complex bearing a tetraamido macrocyclic ligand, [(TAML)Fe<SUP>IV</SUP>(NHTs)]<SUP>−</SUP> (<B>1</B>), was synthesized via a hydrogen atom (H atom) abstraction reaction of an iron(V)-imido complex, [(TAML)Fe<SUP>V</SUP>(NTs)]<SUP>−</SUP> (<B>2</B>), and fully characterized using various spectroscopies. We then investigated (1) the p<I>K</I><SUB>a</SUB> of <B>1</B>, (2) the reaction of <B>1</B> with a carbon-centered radical, and (3) the H atom abstraction reaction of <B>1</B>. To the best of our knowledge, the present study reports for the first time the synthesis and chemical properties/reactions of a high-valent iron(IV)-amido complex.</P> [FIG OMISSION]</BR>

Research on Constitutive Models and Hot Workability of As-Homogenized Al- Zn-Mg-Cu Alloy During Isothermal Compression

Dan Xiao,Xiaoyan Peng,Xiaopeng Liang,Ying Deng,Guofu Xu,Zhimin Yin 대한금속·재료학회 2017 METALS AND MATERIALS International Vol.23 No.3

Hot compression tests of as-homogenized Al-Zn-Mg-Cu alloy were performed at the deformation temperaturerange of 350-450 °C and the strain rate range of 0.001-1 s-1. The Arrhenius-type constitutive equation and theAvrami-type model were established to predict the flow behaviors of the alloy respectively. The processing map atthe true strain of 0.92 was developed to evaluate the workability of the alloy and the related microstructures wereinvestigated. The results show that the Avrami-type model has a higher accuracy to predict flow stress than theArrhenius-type constitutive equation. The stable deformation occurs under high temperature or low strain ratemainly owing to the dynamic recrystallization. Flow instability is prone to occur under the condition of low temperatureand high strain rate due to the initiation and the propagation of micro-cracks. According to the processingmap and corresponding microstructure characteristics, the optimum processing parameters are in the temperaturerange of 380-405 °C and the strain rate range of 0.006-0.035 s-1.

Color Image Coding Based on Shape-Adaptive All Phase Biorthogonal Transform

Wang, Xiaoyan,Wang, Chengyou,Zhou, Xiao,Yang, Zhiqiang Korea Information Processing Society 2017 Journal of information processing systems Vol.13 No.1

This paper proposes a color image coding algorithm based on shape-adaptive all phase biorthogonal transform (SA-APBT). This algorithm is implemented through four procedures: color space conversion, image segmentation, shape coding, and texture coding. Region-of-interest (ROI) and background area are obtained by image segmentation. Shape coding uses chain code. The texture coding of the ROI is prior to the background area. SA-APBT and uniform quantization are adopted in texture coding. Compared with the color image coding algorithm based on shape-adaptive discrete cosine transform (SA-DCT) at the same bit rates, experimental results on test color images reveal that the objective quality and subjective effects of the reconstructed images using the proposed algorithm are better, especially at low bit rates. Moreover, the complexity of the proposed algorithm is reduced because of uniform quantization.

Hyperspectral Image Unmixing for Classification and Recognition : An Overview

Mingyu Nie,Zhi Liu,Hui Xu,Xiaoyan Xiao,Fangqi Su,Jun Chang,Xiaomei Li 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.12

The limited resolution of image sensors and the complex diversity of nature, cause mixed pixel problems in hyperspectral technology. Such problems are common, and increase the complexity of hyperspectral image processing. Hyperspectral unmixing is crucial for hyperspectral image classification and recognition. In unmixing, the image signatures are represented as a linear combination of the basic materials. Unmixing is the process of decomposing a mixed pixel into constituent materials, and calculating the corresponding fractional abundance. If pure materials (end members) are present in an image, unmixing can be divided into two steps, namely, end member extraction and abundance decomposition. On the other hand, if there is no pure material, researchers have devised and investigated unsupervised and semi-supervised spectral unmixing technology. This article presents an overview of the state-of-the-art methods of hyperspectral unmixing and their extensions.

Global Output Feedback Stabilization Control for Nonlinear Systems without Backstepping

Xiao Yan,Hongzheng Quan,Fujin Jia 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.6

In this paper, we study the global output feedback stabilization (GOFS) of nonlinear systems with unknown functions (UFs). Firstly, a lemma is introduced to solve UFs, which avoids the shortcomings of the approximate algorithms. At the same time, this lemma avoids the assumptions of UFs, thus reducing the conservatism of the algorithms. Secondly, based on Lyapunov function analysis, the controller is designed, which solves the GOFS problem of the controlled system. This control algorithm adopts nonbackstepping, so it avoids the complicated calculation of backstepping. Finally, the control algorithm is applied to the Duffing system to verify its effectiveness.

한국 문학교육에서 문학 문식성과 자국어 교육 경험 간의 관계에 대한 고찰 - 중국인 학습자의 한국 현대시 의미 구성 양상을 중심으로 -

김소연 ( Jin¸ Xiao-yan ) 한국문학교육학회 2021 문학교육학 Vol.- No.73

과학기술의 발전이 언어의 도구적 역할을 대체하고 있는 상황에서 중국인 학습자를 위한 한국어교육은 기능적 문식성 교육을 넘어설 필요가 있다. 이러한 맥락에서 이 연구는 중국인 학습자를 위한 한국 문학교육의 지향을 문학문식성과 연관지어 살펴보았다. 중국인 학습자는 경험이 축적된 상태에서 한국 문학을 접하기 때문에 학습자의 다양한 선경험이 한국 문학 이해와 감상에 영향을 미친다. 이 연구는 중국인 학습자의 자국어 교육 경험에 주목하였다. 한국 문학교육에서의 문학 문식성은 문식 활동 주체의 특수성을 충분히 반영하면서 논의되어야 한다. 이에 한국어교육의 관점에서 문학 문식성의 개념을 검토하고, 한국 문학 문식성과 중국인 학습자의 자국어 교육 경험 간의 관계를 설명하였다. 다양한 질적 자료를 통해 중국인 학습자의 자국어 교육 경험이 한국 문학교육에서 어떤 영향을 미치는지 살펴보았는데, 중국인 학습자의 한국 현대시 의미 구성 양상을 ‘지식의 활용에서 자국어 교육 경험의 영향’, ‘경험의 환기에서 자국어 교육 경험의 영향’, ‘태도 형성에서 자국어 교육 경험의 영향’으로 나누어 제시하였다. In a situation where the development of science and technology is replacing the instrumental role of language, Korean language education for Chinese learners needs to go beyond functional literacy education. In this context, this study examined the orientation of Korean literature education for Chinese learners in connection with literary literacy. Since Chinese learners encounter Korean literature while accumulating experience, various prior experiences of learners influence their understanding and appreciation of Korean literature. This study focused on the experience of Chinese learners in their own language education, and explored how learners’ experience in their own language education relates to Korean literature literacy. Literary literacy in Korean literature education should be discussed while fully reflecting the specificity of the subject of literary activities. Therefore, the concept of literary literacy from the perspective of Korean language education was examined, the relationship between Korean literature literacy and Chinese learners’ domestic language education experience was explained, and various qualitative data were examined.