Topology optimization of unsymmetrical complex plate and shell structures bearing multicondition overload

Yangyang Zhang,Yixiao Qin,Jinpeng Gu,Qianqian Jiao,Feng Wang,Zhenshan Guo,Hao Zhang,Jianjun Wang,Chenghong Mi,Huaipeng Zheng 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.8

Unsymmetrical complex plate and shell structure is one of the common engineering structures. In practice, more redundant materials exist because of the irrationality of this kind of structure with heavy load and multiple working conditions, and the study of its topology optimization has become an engaging topic. Using the SIMP model, topological results show that one side of the main web is a hollow structure, and the other side of the auxiliary web is a truss structure. According to the topological results and considering manufacturable processing, a new structure is redesigned, the size and shape of the redesigned structure is secondary optimized, and the final structure is obtained. The method in this paper not only meets the performance requirements of the unsymmetrical complex plate and shell structures, but also realizes the topology and lightweight. The effectiveness scientific research value of the proposed method is verified by engineering examples.

An OVSF Code Based Routing Protocol for Clustered Wireless Sensor Networks

Yangyang Wang,Xiaoling Wu,Jin Wang,Weiping Liu,Weimin Zheng 보안공학연구지원센터 2012 International Journal of Future Generation Communi Vol.5 No.3

A study on the slip velocity on a pair of asymmetric electrodes for AC-electroosmosis in a microchannel

Yangyang Wang,서용권,강상모 대한기계학회 2009 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.23 No.3

In numerical studies on microscale electroosmotic flows, the electric double layer (EDL) effect is usually predicted by solving the traditional Navier-Stokes equation subjected to the slip velocity induced by the electric-charged wall as a boundary condition. Recently, Suh and Kang (Physical Review E 77, 2008) presented the asymptotic solutions of the ion transport equations near a polarized electrode under the action of an AC field, and then proposed a new theoretical model of the slip velocity on the electrode considering the ion adsorption effect. In the present paper, we apply the model to a two-dimensional AC-electroosmotic flow in a microchannel to calculate the slip velocity on a pair of coplanar asymmetric electrodes embedded on the bottom wall, and then experimentally measure the slip velocity using the micro-PIV technique to validate the theoretical model. Comparison shows an excellent overall match between the theoretical and experimental results, except for on the narrow electrode at low frequencies. Next, we numerically perform parametric studies regarding the AC frequency, effective Stern-layer thickness and ion adsorption effect to further understand the characteristics of the AC electroosmotic flow. Results show that, as the frequency increases, the slip velocity also increases. In addition, the velocity decreases with increasing either Stern-layer thickness or ion adsorption effect.

HALF-METALLIC SILICENE AND GERMANENE NANORIBBONS: TOWARDS HIGH-PERFORMANCE SPINTRONICS DEVICE

YANGYANG WANG,JIAXIN ZHENG,ZEYUAN NI,RUIXIANG FEI,QIHANG LIU,RUGE QUHE,CHENGYONG XU 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2012 NANO Vol.7 No.5

By using first-principles calculations, we predict that an in-plane homogenous electrical ¯eld can induce half-metallicity in hydrogen-terminated zigzag silicene and germanene nanoribbons (ZSiNRs and ZGeNRs). A dual-gated ¯nite ZSiNR device reveals a nearly perfect spin-¯lter e±ciency (SFE)of up to 99% while a quadruple-gated ¯nite ZSiNR device serves as an effective spin ¯eld e®ect transistor (FET) with an on/o® current ratio of over 100 from ab initio quantum transport simulation. This discovery opens up novel prospect of silicene and germanene in spintronics.

Evaluation of Mixing Performance in Several Designs for Microfluidic Channel Mixers

왕양양(Yangyang Wang),서용권(Yongkweon Suh),강상모(Sangmo Kang) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5

We conducted a numerical study of AC-electroosmotic (alternating current) effect on the fluid flow and mixing in a 3-D microchannel. The microchannel used as an efficient micro-mixer is composed of a channel and a series of pairs of electrodes attached in zigzag pattern on the bottom wall. The AC electric field is applied to the electrodes so that a steady flow current takes place around the electrodes. This current is flowing across the channel and thus contributing to the mixing of the fluid within the channel. We performed numerical simulations by using a commercial code to obtain a steady flow field. This steady flow is then used in evaluation of the mixing performance via the concept of mixing index. It was found that good combination of two kinds of electrode, which gave us a good mixing, is not simple harmonic. And when the length ratio of these two kinds of electrode is 2:1, we can get the best mixing effect.

Prognostic significance of lymphovascular space invasion in patients with endometrioid endometrial cancer: a retrospective study from a single center

Yibo Dai,Yangyang Dong,Yuan Cheng,Hongyi Hou,Jingyuan Wang,Zhiqi Wang,Jianliu Wang 대한부인종양학회 2020 Journal of Gynecologic Oncology Vol.31 No.3

Objective: This study aims to analyze factors associated with lymphovascular space invasion (LVSI) and evaluate the prognostic significance of LVSI in Chinese endometrioid endometrial cancer (EEC) patients. Methods: Five-hundred eighty-four EEC patients undergoing surgery in our center from 2006 to 2016 were selected for analysis. Univariate analysis and multivariate logistic regression were used to examine relevant factors of LVSI. To evaluate the prognostic role of LVSI, survival analyses were conducted. In survival analyses, both multivariate Cox regression and propensity score matching were used to control the confounders. Results: The incidence of LVSI was 12.16% (71/584). Diabetes history (p=0.021), lymph node metastasis (p=0.005), deep myometrial invasion (p<0.001) and negative PR expression (p=0.007) were independently associated with LVSI. Both Kaplan-Meier method and univariate Cox regressions showed LVSI negative and positive cases had similar tumor-specific survival (TSS) and disease-free survival (DFS). After adjusting for the influence of adjuvant therapy and other clinicopathological factors with multivariate Cox regressions, LVSI still could not bring additional survival risk to the patients (p=0.280 and p=0.650 for TSS and DFS, respectively). This result was verified by Kaplan-Meier survival analyses after propensity score matching (p=0.234 and p=0.765 for TSS and DFS, respectively). Conclusion: LVSI does not significantly compromise the survival outcome of Chinese EEC patients.

Influence of B-Complex Vitamins on the Pharmacokinetics of Ginsenosides Rg1, Rb1, and Ro After Oral Administration

Peihe Zheng,Yinbin Chen,Yangyang Fu,Hecheng Wang,Jia Wang,Siwen Zheng,Shengyuan Xiao,Yingping Wang 한국식품영양과학회 2017 Journal of medicinal food Vol.20 No.11

After cultivation of ginseng, ginsenosides, which are the major active ingredients of gingeng, were approved for use by the food industry, and began to be used as added functional ingredients to try to improve the quality and price of functional foods. However, the interaction between different types of ginsenosides and nutrients needs further study. We investigated the effect of B-complex vitamins (which are essential nutrients) on the pharmacokinetics of the ginsenosides protopanaxatriol-type saponin Rg1, protopanaxadiol-type saponin Rb1, and oleanolic acid-type saponin Ro after oral administration. Ginsenosides Rg1, Rb1, and Ro, with or without B-complex vitamins, respectively, were administered orally to rats to evaluate their pharmacokinetics. The concentration of ginsenosides in plasma was determined by liquid chromatography/tandem mass spectrometry. Pharmacokinetic parameters were fitted using WinNonlin v6.2. After oral coadministration with B-complex vitamins, the area under the concentration–time curve from zero to infinity (AUC0–∞) of ginsenoside Rg1 was reduced by 70%, that of ginsenoside Rb1 was reduced by 43%, and that of ginsenoside Ro was reduced by 34%. The AUC0–∞ of ginsenosides Rg1 and Rb1 showed significant differences between different treatments, but the AUC0–∞ of ginsenoside Ro did not. These results suggest significant ginsenoside-nutrient interactions between ginsenosides Rg1, Rb1, and B-complex vitamins.

Porous WO₃ monolith-based photoanodes for high-efficient photoelectrochemical water splitting

Wang, Yina,Zhang, Fangfang,Zhao, Guoyan,Zhao, Yingao,Ren, Yangyang,Zhang, Huijun,Zhang, Linyu,Du, Jimin,Han, Yumin,Kang, Dae Joon Elsevier 2019 CERAMICS INTERNATIONAL Vol.45 No.6

<P><B>Abstract</B></P> <P>We report a successful fabrication of low-cost, high-efficient, structurally-rigid, porous WO<SUB>3</SUB> photoelectrochemical (PEC) catalysts using polystyrene as the template by a sol-gel method and a high-temperature annealing treatment. The scanning electron microscopy and Brunauer-Emmett-Teller surface analysis results indicate that such WO<SUB>3</SUB> monoliths possess a porous structure and a large specific surface area, which can supply lots of photogenerated charge transfer pathways as well as more surface PEC active sites. Compared with a commercially available WO<SUB>3</SUB>, our highly porous WO<SUB>3</SUB> PEC catalysts show an excellent PEC water splitting activity. Particularly, the porous WO<SUB>3</SUB> photoanodes calcinated in the presence of oxygen atmosphere at 450 °C for 7 h show the best PEC performance exhibiting the photocurrent density of 0.97 mA/cm<SUP>2</SUP> at 1.23 V versus reversible the hydrogen electrode and the incident photon-to-current conversion efficiency up to 48.9% at 420 nm in 0.5 M Na<SUB>2</SUB>SO<SUB>4</SUB> electrolyte under AM 1.5 G irradiation. Such excellent PEC performance is due to the high porosity of the WO<SUB>3</SUB>, promoting the fast transfer and the separation rate of photogenerated carriers during the PEC water splitting process.</P>

3D Reconstruction of Remote Sensing Image Using Region Growing Combining with CMVS-PMVS

Aili Wang,Na An,Yangyang Zhao,Yuji Iwahori,Rui Kang 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.8

The characteristics of remote sensing image is not obvious and can not reflect the be reconstructed the detail characters of the objects. For the sparse points in multi images fusion results, texture selection and it is relatively difficult problems, for accurate reconstruction of remote sensing image details, this paper presents CMVS-PMVS(cluster multi view stereo- patch based multi view stereo) combining with region growing for computing dense matching points. First, select some seed points by region growing algorithm, and find the matching relationship between the seed points, followed by the matching relation from the seed point to spread until to the entire image. Then the image set are clustered by CMVS in order to reduce the amount of data in the process of reconstruction, and the operation rate and reconstruction accuracy can be improved. PMVS reconstruction method is used to complete the reconstruction task by matching, expanding and filtering three steps. The experimental results showed that the point cloud is dense enough which are reconstructed by the 3d reconstruction algorithm based on regional growth combining CMVS-PMVS and well expressed the practical model of object reconstruction, the reconstruction of objects in remote sensing images has very strong practicability.

A Novel Feature Detection Algorithm Based on Improved 2DPCA- SIFT

AiliWang,Yangyang Zhao,Jiaying Zhao,Yuji Iwahori,Xinyuan Wang 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.6

Stable local feature and representation is a fundamental component of many image registration, 3D reconstruction and object recognition algorithms. SIFT is a good descriptor that encodes the salient aspects of the image gradient in the feature point’s neighborhood. This paper improved SIFT- based local image descriptor and proposed a SIFT feature matching algorithm based on improved 2DPCA which can eliminate both rows and columns of relevance. Experimental results show that improved 2DPCA-SIFT algorithm is relatively stable, accurate and fast.