Residual Stress Distribution in Hard-Facing of Pressure Relief Valve Seat

Ai, Li,Yu, Xinhai,Jiang, Wenchun,Woo, Wanchuck,Ze, Xiaofeng,Tu, Shan-Tung AMERICAN SOCIETY MECHANICAL ENGINEERS 2014 Journal of Pressure Vessel Technology Vol.136 No.6

<P>In this study, for the hard-facing of spring-loaded pressure relief valve seats, the residual stress distributions after the tungsten inert gas welding, (TIG) postwelded heat treatment and subsequent surface turning were investigated. The heat input parameters of welding were calibrated using an infrared imaging and thermocouples. The residual stress distributions were computed using three-dimensional finite element model. The neutron diffraction approach was employed to verify the finite element calculation. It is found that, the surface temperature during hard-facing welding shows a double ellipsoidal shape with the highest value of around 1570 degrees C. The high residual stress zones are located exactly under the welded joint except a slight deviation in the hoop direction. The magnitudes of tensile residual stresses in the three directions increase with their corresponding locations from the root of the joint into the base metal. The residual stresses in all of the three directions decrease significantly after the heat treatment. After surface turning, the residual stresses are tensile except for those close to the inner surface that are compressive in axial and radial directions.</P>

Nonlinear $\xi$-Lie-$\ast$-derivations on von Neumann algebras

Aili Yang 강원경기수학회 2019 한국수학논문집 Vol.27 No.4

Let $\mathscr{B(H)}$ be the algebra of all bounded linear operators on a complex Hilbert space $\mathscr{H}$ and $\mathscr{M}\subseteq\mathscr{B(H)}$ be a von Neumann algebra without central abelian projections. Let $\xi$ be a non-zero scalar. In this paper, it is proved that a mapping $\varphi:\mathscr{M}\rightarrow\mathscr{B(H)}$ satisfies $\varphi([A,B]^{\xi}_{\ast})=[\varphi(A),B]^{\xi}_{\ast}+[A,\varphi(B)]^{\xi}_{\ast}$ for all $A,B\in\mathscr{M}$ if and only if $\varphi$ is an additive $\ast$-derivation and $\varphi(\xi A)=\xi\varphi(A)$ for all $A\in\mathscr{M}.$

A Novel Image Superresolution Reconstruction Algorithm Based on Sparse Representation

Aili Wang,Xinyuan Wang,Yuji Iwahori,Yuan Feng,Na Jiang 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.6

Superresolution image reconstruction technique uses single or a series of low-resolution images to reconstruct a high resolution image without changing the hardware devices, while improving image quality and the spatial resolution of the image. High resolution means the image with a higher pixel density, can provide more details. In this paper, a novel image superresolution algorithm based on sparse representation is studied. During over-complete dictionary of the training phase, the proposed method improves two aspects including feature extraction and dimension reduction. In the feature extraction process, combining the second derivative with the gradient direction, we construct a new descent direction to improve gradient method. The convergence speed of the new algorithm is faster than the gradient method and can get better results. Then improved two-dimensional Principal Component Analysis (2DPCA) algorithm is used to reduce the dimension, it could eliminate the correlation of the image lines and column. Experiment results show that this method of image reconstruction is better and faster for high resolution image reconstruction.

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.

Pedestrian Detection Algorithm Combining HOG and SLBP

Aili Wang,Mingxiao Wang,Jitao Zhang,Yuji Iwahori,Bo Wang 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.10

In order to solve the problem of pedestrian detection performance, the described operator was improved. In this paper, semantic local binary pattern (SLBP) and histogram of oriented gradient (HOG) are combined as new feature operator. This feature method would enrich the information and enhance the detection performance. And then histogram intersection kernel support vector machine (HIKSVM) classifier is trained by the augment feature. Because the time cost is too large by the conventional SVM. HIKSVM could make up this drawback, and significantly reduce the training time. The experiments on the INRIA pedestrian dataset show that the method obtained significant improvement in accuracy comparing to HOG descriptors.

[BMIM]Cl-nAlCl3 ionic liquid-catalyzed redistribution reaction between methyltrichlorosilane and low-boiling residue to dimethyldichlorosilane

Aili Wang,Yiqian Jiang,Weiguang Chen,Yanjun Liu,Yutang Shen,Tingshun Jiang,Zhanao Wu,Hengbo Yin 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.1

Methyltrichlorosilane and low-boiling residue from the synthesis of methylchlorosilanes via the direct reaction of silicon and methyl chloride were effectively converted to high-valued dimethyldichlorosilane catalyzed by 1-butyl-3-methylimidazolium chloroaluminate, [BMIM]Cl-nAlCl3, ionic liquid catalysts. The yield of dimethyldichlorosilane reached 69.1% when the redistribution reaction between methyltrichlorosilane and low-boiling residue was catalyzed by [BMIM]Cl-6AlCl3 at a reaction temperature of 150 8C for 300 min. The conversion of methyltrichlorosilane was 87.8%. And the conversions of tetramethylsilane, methylhydrodichlorosilane, and dimethylhydrochlorosilane present in low-boiling residue were ca. 100%, respectively. The ionic liquids could be recycled efficiently. This research provided an eco-friendly and economical route for the treatment of methyltrichlorosilane and low-boiling residue, which were the by-products in the direct synthesis of methylchlorosilanes. The possible reaction route was also discussed.

경찰 민간인 통역요원 직무 수행 중 애로사항 연구 -경찰 통역요원 대상 심층 인터뷰를 중심으로-

장애리(Aili Chang) 한국번역학회 2022 번역학연구 Vol.23 No.2

Review of Several Experimental Methods for Characterization of Micro- and Nano-Scale Pores in Cement-Based Material

Abudushalamu Aili,Ippei Maruyama 한국콘크리트학회 2020 International Journal of Concrete Structures and M Vol.14 No.6

Mechanical properties and durability of cement-based materials are largely affected by pore structures. This paper provides an overview of several experimental techniques to characterize pore size distribution and specific surface area, with focus on pores in calcium silicate hydrates. The reviewed experimental techniques are nitrogen and water vapor sorption isotherm, proton nuclear magnetic resonance (¹H-NMR) and small-angle scattering (SAS). Different pretreatment methods are compared for sorption measurements. Pore size distribution and specific surface area are analyzed using data from different methods to understand difference and consistency of these methods. It is found that pore size distribution calculated from sorption isotherm is very sensitive to adsorption model. Though specific surface areas from different techniques are quite different from each other, they are all able to detect the microstructural alteration due to long-term drying.

Conversion of Lignin-Nanofibers to CNFs

Ma Aili,Zhou Li,Chang Jie 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2015 NANO Vol.10 No.6

In this study, a novel method, electrospinning, was used to prepare lignin-based carbon nanofibers. The major material was lignin. The chemical and thermal properties of different lignins were characterized to determine their suitability for partial incorporation of polyacrylonitrile (PAN). Then the precursor fibers were carbonized at a temperature from 600℃ to 1000℃, respectively to prepare biomass-based carbon nanofibers. The influences of carbonization temperature on prepared carbon nanofibers were investigated by X-ray diffraction (XRD), Raman, thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The results indicated that the diameter of prepared precursor fibers and carbon fibers were about 200 nm and 100 nm, respectively. The increase of temperature has little influence on the carbon fiber graphitization degree. The D band of the carbon fibers carbonized at 900℃ is lowest. The thermal stability of the carbon fibers changes little with rising temperature when carbonized temperature exceeds 900℃, and carbon fibers carbonized under 900℃ have most compact structure. Therefore, the above conclusions make clearly that 900℃ is the optimal carbonization temperature for preparing lignin-based carbon nanofibers in this technique. Meanwhile, the study is a doubled-edged enterprise that aims to recycle the waste from pulping industry as well as to turn it into a valuable material.

한국어 한자 어휘 연구의 유형에 대하여-중국인이 작성한 한국어 논문을 중심으로-

왕애려 ( Aili Wang ) 경남대학교 인문과학연구소 2017 人文論叢 Vol.43 No.-

이 글은 한국에서 유학을 하고 있는 중국인 유학생들이 `한자어`를 주제로 하여 쓴 논문들을 검토하여 그 유형을 분류하고, 경향을 파악해서 앞으로 어떠한 방향으로 연구를 하는 것이 좋을지에 대해 고민해 보는 것을 목적으로 하고 있다. 중국인 학습자들이 한국어를 배울 때, 가장 쉽게 배울 수 있는 것도 한자 어휘이고, 가장 배우기가 어려운 것도 한자 어휘이다. 이는 같은 형태의 한자어가 다른 의미를 가지고 사용될 수도 있다는 점에서 기인하는 것이다. 이런 점에 착안하여 중국인 유학생들은 한자 어휘의 형태와 의미 차이에 대한 논의, 그리고 이러한 차이점을 가진 한자어 교육 방안에 대한 논의들을 만들어 내기 시작했다. 하지만 현재 한자 어휘의 형태적 유사성과 의미적 차별성에서 기인하는 내용의 논의들은 논의 내용의 차별성을 찾아보기 힘들 만큼 비슷한 것들이 많아졌다. 소모적인 논의의 생성만이 가득한 것이다. 이러한 내용들을 감안하여 이 글에서는 앞으로 중국인 학습자들이 논문을 작성함에 있어 지녀할 태도에 대해 제시하고, 한국과 중국 양국에서 개선해야 할 점에 대해서도 언급하였으며, 중국인 유학생들이 앞으로 연구대상으로 삼을 수 있는 영역에 대해서도 생각해 보았다. The purpose of this writing is reviewing the theses which the Chinese students in Korea wrote with the them of words written in Chinese characters, categorizing the types, grasping the trend, and thinking deeply about what directions the research should be heading for. When Chinese Korean learners learn Korean, the easiest and the most difficult thing is the Sino Korean words, because words in the same form but with different meanings are often used in Korean. Based on this aspect, Chinese students started to study the differences of Sino-Korean words in form and meaning and the teaching methods of the Sino-Korean words with these differences. However, nowadays, it is very difficult to make distinctions among the research contents which were based on the morphological similarities and the semantic differences of the Sino-Korean words. Moreover, there are many similar studies also. It seems that only consumptive studies are being written. Considering this point, this paper proposed the attitudes that the Chinese learners should have when they do studies, presented the points that should be improved between Korea and China and figured out the fields that can be considered as research subjects in the future.