A Hybrid Visibility Determination Method to Get Vector Silhouette

Lu, Xuemei,Lee, Ki-Jung,WhangBo, Taeg-Keun Korea Multimedia Society 2008 멀티미디어학회논문지 Vol.11 No.6

Silhouette is useful in computer graphics for a number of techniques such as non-photorealistic rendering, silhouette clipping, and blueprint generating. Methods for generating silhouette are classified into three categories: image-based, object-based, and hybrid-based. Hybrid-based method is effective in terms of time complexity but spatial coherence problem still remains. In this paper, we proposed a new hybrid-based method which produces 3D data for silhouette and also guarantees no spatial coherence problem. To verify the efficiency of the proposed algorithm, several experiments are conducted for various 3D models from simple to quite complex. Results show that our algorithm generates no gap between any two consecutive silhouette lines when the silhouette model is magnified significantly.

A Hybrid Visibility Determination Method to Get Vector Silhouette

Xuemei Lu,Kijung Lee,Taegkeun Whangbo 한국멀티미디어학회 2008 멀티미디어학회논문지 Vol.11 No.6

A Study on Fast Streaming Rendering

Xuemei Lu(여설매),Sungjong Eun(은성종),Kijung Lee(이기정),Taegkeun Whangbo(황보택근) 한국멀티미디어학회 2007 한국멀티미디어학회 학술발표논문집 Vol.2007 No.2

A NEW INTERACTIVE LOD SELECTION ALGORITHM FOR POINT BASED RENDERING

Xuemei Lu,TaegKeun Whangbo 한국멀티미디어학회 2006 한국멀티미디어학회 국제학술대회 Vol.2006 No.-

For PBR (Point Based Rendering), the main steps that prominently affect the rendering result are hierarchical data structure, LOD selection method and rendering primitives (triangle, point, surfel[1]). In this paper we generate a hierarchical structure with tight-octree and write it back to a file which only adds the level information to the original file. And we propose a new method to do LOD selection, based on the user interactive information and the precalculated bounding box information. As the sampling data getting tremendous, more than one sampling points will project into a pixel. This brings point based rendering becoming popular. Our implementation has demonstrated the algorithm on huge regular sampling models containing millions of samplings.

Study on suppression mechanism of electron emission from Mo grid coated with carbon film by dual ion beam deposition

Lu Yuehui,Wu Xuemei,Liu Xianghuai,Zhuge Lanjian 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.45 No.3

It is problematic that electrons are emitted from the Mo grid of pulsed-controlled grid traveling wave tubes, caused by the contamination of cathode evaporation material, i.e. BaO. Some studies show that a Mo grid coated with carbon can greatly suppress grid electron emission. However, the reason for the electron emission suppression is not completely clear. To understand the mechanism of electron emission suppression of a BaO/C/Mo system, carbon lms were prepared on Mo substrates at room temperature by means of DIBSD (dual ion beam sputtering deposition), and BaO layers were coated by using a chemical method. Post-annealing was conducted under a owing nitrogen ambient at 700 C for 1.5 hours. The structure of the as-deposited carbon lms was evaluated by TEM, AES and Raman spectroscopy. The annealed samples, the BaO/ Mo and BaO/C/Mo systems, were analyzed by XPS. The results suggest that the chemical reaction between BaO and C at high temperature eliminates the concentrations of Ba or BaO on the surface of the C/Mo system. It can be believed that the high work function material used as the grid surface coating and elimination of BaO on its surface have a critical eect on grid electron emission suppression. Moreover, the carbon lm was characterized by density, homogeneity and high adhesion, owing to the features of DIBSD.

Vibration behavior of trapezoidal sandwich plate with functionally graded-porous core and graphene platelet-reinforced layers

Di Liang,Qiong Wu,Xuemei Lu,Vahid Tahouneh 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.36 No.1

In this study, free vibration behavior of trapezoidal sandwich plates with porous core and two graphene platelets (GPLs) reinforced nanocomposite outer layers are presented. The distribution of pores and GPLs are supposed to be functionally graded (FG) along the thickness of core and nanocomposite layers, respectively. The effective Young’s modulus of the GPL-reinforced (GPLR) nanocomposite layers is determined using the modified Halpin-Tsai micromechanics model, while the Poisson’s ratio and density are computed by the rule of mixtures. The FSDT plate theory is utilized to establish governing partial differential equations and boundary conditions (B.C.s) for trapezoidal plate. The governing equations together with related B.C.s are discretized using a mapping- generalized differential quadrature (GDQ) method in the spatial domain. Then natural frequencies of the trapezoidal sandwich plates are obtained by GDQ method. Validity of current study is evaluated by comparing its numerical results with those available in the literature. A special attention is drawn to the role of GPLs weight fraction, GPLs patterns of two faces through the thickness, porosity coefficient and distribution of porosity on natural frequencies characteristics. New results show the importance of this permeates on vibrational characteristics of porous/GPLR nanocomposite plates. Finally, the influences of B.C.s and dimension as well as the plate geometry such as face to core thickness ratio on the vibration behaviors of the trapezoidal plates are discussed.

MondoA Is Required for Normal Myogenesis and Regulation of the Skeletal Muscle Glycogen Content in Mice

Hui Ran,Yao Lu,Qi Zhang,Qiuyue Hu,Junmei Zhao,Kai Wang,Xuemei Tong,Qing Su 대한당뇨병학회 2021 Diabetes and Metabolism Journal Vol.45 No.3

Background: Skeletal muscle is the largest tissue in the human body, and it plays a major role in exerting force and maintaining metabolism homeostasis. The role of muscle transcription factors in the regulation of metabolism is not fully understood. MondoA is a glucose-sensing transcription factor that is highly expressed in skeletal muscle. Previous studies suggest that MondoA can influence systemic metabolism homeostasis. However, the function of MondoA in the skeletal muscle remains unclear. Methods: We generated muscle-specific MondoA knockout (MAKO) mice and analyzed the skeletal muscle morphology and glycogen content. Along with skeletal muscle from MAKO mice, C2C12 myocytes transfected with small interfering RNA against MondoA were also used to investigate the role and potential mechanism of MondoA in the development and glycogen metabolism of skeletal muscle. Results: MAKO caused muscle fiber atrophy, reduced the proportion of type II fibers compared to type I fibers, and increased the muscle glycogen level. MondoA knockdown inhibited myoblast proliferation, migration, and differentiation by inhibiting the phosphatase and tensin homolog (PTEN)/phosphoinositide 3-kinase (PI3K)/Akt pathway. Further mechanistic experiments revealed that the increased muscle glycogen in MAKO mice was caused by thioredoxin-interacting protein (TXNIP) downregulation, which led to upregulation of glucose transporter 4 (GLUT4), potentially increasing glucose uptake. Conclusion: MondoA appears to mediate mouse myofiber development, and MondoA decreases the muscle glycogen level. The findings indicate the potential function of MondoA in skeletal muscle, linking the glucose-related transcription factor to myogenesis and skeletal myofiber glycogen metabolism.

Nutrigenomics reveals potential genetic underpinning of diverse taste preference of Chinese men

Zhouhai Zhu,Junpu Mei,Silong Sun,Sheming Lu,Meng Li,Ying Guan,Ying Chen,Yuqiong Xu,Tao Zhang,Fengxue Shi,Xuemei Li,Mingming Miao,Shancen Zhao,Qian Gao,Qili Mi,Ping Tang,Jianhua Yao 한국유전학회 2021 Genes & Genomics Vol.43 No.6

Background Taste preference varies geographically in China. However, studies on Chinese people’s taste preference in different regions of China are limited, and are lack of research on the mechanism of diferences in taste preference, especially in genetics. Objective This study aims to investigate the characteristics of taste preference of Chinese men, and estimate whether diverse taste preference in Chinese have genetic underpinning. Methods We conducted a questionnaire survey on taste preferences on 1076 males from 10 regions of China, and collected another 1427 males from the same regions which genotyped by microarray. We compared the correlation between diferent taste preference, and evaluated the correlation between the mutation frequency of inhouse database and diferent taste preference. The putative taste-preference-related genes were further utilized to estimate the candidate relationship on gene and gene network in diferent taste preference. Results There was a correlation between diferent taste preferences in Chinese men. We found 31 SNPs associated with 6 kind of taste preferences. These SNPs located within or nearby 36 genes, and the tastes associated with 4 of these genes (TRPV1, AGT, ASIC2 and GLP1R) are consistent with the previous studies. Moreover, in diferent tastes which were suggested to be associated with each other, some putative related genes were the same or in the same gene network, such as pathways related with blood pressure, response to stimulus and nervous system. Conclusions This study indicates that the diverse taste preference of Chinese men may have genetic underpinning.

Cytophaga hutchinsonii chu_2177, encoding the O-antigen ligase, is essential for cellulose degradation

Tan Yahong,Song Wenxia,Gao Lijuan,Zhang Weican,Lu Xuemei 한국미생물학회 2022 The journal of microbiology Vol.60 No.4

Cytophaga hutchinsonii can efficiently degrade crystalline cellulose, in which the cell surface cellulases secreted by the type IX secretion system (T9SS) play important roles, but the degradation mechanism remains unclear, and the anchor mechanism of cellulases on the outer membrane in C. hutchinsonii has not been studied. Here, chu_2177 was identified by transposon mutagenesis and was proved to be indispensable for cellulose utilization in C. hutchinsonii. Disruption of chu_2177 resulted in O-antigen deficiency and chu_ 177 could confer O-antigen ligase activity upon an Escherichia coli waal mutant, indicating that chu_2177 encoded the Ontigen ligase. Moreover, deletion of chu_2177 caused defects in cellulose utilization, cell motility, biofilm formation, and stress resistance. Further study showed that the endoglucanase activity was markedly decreased in the outer membrane but was increased in the culture fluid without chu_2177. Western blot proved that endoglucanase CHU_1336 was not located on the outer membrane but was released in the culture fluid of the Δ2177 mutant. Further proteomics analysis showed that many cargo proteins of T9SS were missing in the outer membrane of the Δ2177 mutant. Our study revealed that the deletion of chu_2177 affected the localization of many T9SS cargo proteins including cellulases on the outer membrane of C. hutchinsonii.