A fast image-stitching algorithm for characterization of cracks in large-scale structures

Linlin Wang,Billie F. Spencer Jr,Junjie Li,Pan Hu 국제구조공학회 2021 Smart Structures and Systems, An International Jou Vol.27 No.4

Visual inspection of concrete cracks has been widely used in structural health monitoring (SHM). Capturing highresolution images is an effective method to visualize a complete crack, but it is difficult to show a whole crack from a single high-resolution image. One feasible method is using image stitching technique to stitch several images into a complete crack map. However, the current image stitching method is a computationally intensive process. Numerous images are required to cover large-scale structures with sufficient resolution, this can be computationally prohibitive. To address this problem, an improved image stitching method for crack damage evaluation is proposed, which can quickly stitch the crack images without affecting the quality of the stitching or the resulting images. Rather than first stitching the images together and then determining the crack maps, we propose to first develop the crack maps for the individual images and then stitch them together. The proposed method reduces the number of redundant matching points between the original images by combining their characteristics during image stitching, so it can reduce the calculation time without affecting the quality. Also, the results will not be influenced by the image stitching seam, which can reduce the complexity of the algorithm. Several experimental results are provided in this article to demonstrate that the proposed method can reduce the calculation time without affecting the quality of image stitching and have better robustness than the current method in use.

Washback of the College English Test – Band Four on English Teaching and Learning in China

Linlin Wang,Elvis Wagner 아시아영어교육학회 2020 The Journal of Asia TEFL Vol.17 No.4

This study examined the possible washback effects of the latest version of the College English Test–Band Four (CET-4) test from the test-takers’ perspective, focusing primarily on the listening section. Using survey methodology, 305 Chinese EFL learners from both a first- and a second-tier city in China rated the difficulty, usefulness, and level of authenticity of the CET-4 listening, the non-listening test sections, the degree to which they adapted their learning behaviors to the test, and how much their teachers adapted their instruction to address the CET-4. The results indicated learners from the second-tier Chinese city considered the CET-4 more difficult, authentic, and useful, and that it had more of an impact on teaching and learning. Despite these differences, both groups rated the listening section as more difficult, less useful, and less authentic than the other sections of the test. Finally, the listening section was perceived to have more of an impact on student’s learning than the perceived impact on teaching. Based on these results, we argue that the possible washback effects of a test should be a fundamental consideration in the development and validation of a test, not just an afterthought (Bachman, 2005; Chalhoub-Deville & O’Sullivan, 2020; Messick, 1996).

Analysis of thermoelastic damping in bilayered rectangular microplate resonators with three-dimensional heat conduction

Linlin Wang,Xiaopeng Li,Wujiu Pan,Zemin Yang,Jinchi Xu 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.4

Thermoelastic damping (TED) is considered to be the main internal energy dissipation mechanism in microresonators, the study of which has become increasingly significant in the design of microresonators with high quality factor. In this paper, the bilayered cantilever, fixed-fixed and fully clamped rectangular microplate resonators are taken as the research object, and then three theoretical models of thermoelastic damping with three-dimensional heat conduction are built. The analysis on convergence items of the present threedimensional models with different combinations of materials are carried out, and the influence of material plating on TED in Si microplate resonators is also analyzed. The analysis on the effects of the geometry size and boundary conditions on thermoelastic damping of microresonators at the first-order natural frequency are both carried out. Moreover, in order to verify the validation and accuracy of the present three-dimensional (3-D) models, the previous one-dimensional (1-D) models and the FEM models built in this paper are used to compare with the present models. Finally, the validation and accuracy of the present three-dimensional models are confirmed.

Indications of the sedimentary environments by the sedimentary characteristics and trace elements of Ordovician Majiagou Formation, Northern Shaanxi salt basin

LinLin Wang,Tao Shi,Dawei Chang,Haitao Zhang 한국자원공학회 2020 Geosystem engineering Vol.23 No.6

The abundant geochemical information on elements in the autogenous sedimentary rocks can help reconstruct the paleoenvironment of the stratigraphic sedimentation period. Based on the analysis of sedimentary characteristics of Ordovician Majiagou Formation and the trace elements in limestone, dolomite and gypsum rocks in Northern Shaanxi salt basin, the relationship between the distribution of trace elements of Majiagou Formation and the sedimentary environment is discussed. The results display that Majiagou Formation is mainly composed of the sedimentation of carbonate rocks and evaporites, and the subfacies of open platform and restricted platform are developed. The trace element analysis shows that the deposition period of the Majiagou Formation is dominated by dry hot climate, and there are alternating dry and wet seasons in climate evolution. In middle Ordovician, the sedimentary environment of Majiagou Formation was undergoing the transformation of oxygen enrichment-oxygen deficiency-anoxic environment.

Grape seed proanthocyanidins protect retinal ganglion cells by inhibiting oxidative stress and mitochondrial alteration

Linlin Li,Xing Geng,Lili Tian,Dabo Wang,Qin Wang 대한약학회 2020 Archives of Pharmacal Research Vol.43 No.10

Grape seed proanthocyanidins (GSP) are knownas condensed tannins and have been used as an anti-oxidantin various neurodegenerative diseases. In our study, GSPwas used as a daily dietary supplement and the neuroprotectiveeffects were evaluated on the retinal ganglion cells(RGCs) in the retinal tissues in glaucomatous DBA/2D (D2)mice. D2 mice and age-matched non-glaucomatous DBA/2JGpnmb+(D2-Gpnmb+) mice were fed with GSP or a controldiet for up to 6 months. The intraocular pressure (IOP), RGCsurvival, glial fibrillary acidic protein (GFAP), the levels ofapoptotic proteins, and the expression of oxidative stressmarkers in retinal tissues were determined. In our study, theneuroprotective effects of GSP on retinal tissues were confirmed,as evidenced by (a) GSP inhibited the IOP elevationin D2 mice; (b) GSP enhanced RGC survival and mediatedthe apoptotic protein expression; (c) GSP suppressed GFAPexpression; and (d) the oxidative stress and the levels ofmitochondrial reactive oxygen species were regulated byGSP. Our findings indicate that GSP has promising potentialto preserve retinal tissue functions via regulating oxidativestress and mitochondrial functions.

Nitrogen and boron-incorporated carbon dots for the sequential sensing of ferric ions and ascorbic acid sensitively and selectively

Wang, Linlin,Chung, Jin Suk,Hur, Seung Hyun Elsevier 2019 Dyes and pigments Vol.171 No.-

<P><B>Abstract</B></P> <P>Nitrogen and boron-incorporated carbon dots (NBCDs) were fabricated using a hydrothermal process with ascorbic acid (AA) and 4-aminobenzenebornic acid hydrochloride as novel precursors. The size and morphology were examined using the appropriate spectrochemical characterization. The NBCDs emission was examined in the presence of different metal ions. The fluorescence was quenched selectively in the presence of the Fe<SUP>3+</SUP> ions and with increasing Fe<SUP>3+</SUP> concentration in the reaction medium. From this fluorescence “Turn Off” phenomenon, Fe<SUP>3+</SUP> could be detected in aqueous solution with a limit of detection (LOD) of 7.50 μM. This quenched fluorescence was recovered in the presence of AA selectively. This “Turn On” phenomenon was AA concentration dependent and AA could be detected in aqueous solution with a LOD value of 7.72 μM. Analysis of a real sample was conducted for the detection of Fe<SUP>3+</SUP> ions in solution, which was collected from iron sheet reacted over the pH range of 2–7 for set times.</P> <P><B>Highlights</B></P> <P> <UL> <LI> N and B-incorporated carbon dots (NBCDs) were fabricated using ascorbic acid and 4-aminobenzenebornic acid hydrochloride. </LI> <LI> The concentration of Fe<SUP>3+</SUP> ions and AA can be determined by the “On-Off-On” mechanism in one pot with high selectivity. </LI> <LI> NBCDs could effectively evaluate the strength of acid rain. </LI> </UL> </P>

间断-平衡理论视角下70年中国农地经营政策变迁分析

王琳琳 ( Wang Linlin ) 성균관대학교 성균중국연구소 2020 중국사회과학논총 Vol.2 No.2

建国后, 中国农地经营政策历经家庭自主经营、集体统一经营和家庭承包经营非渐进变迁过程。以间断-平衡理论为框架, 编码分析1949年到2019年人民日报相关报道发现, 农地经营政策变迁实际是政策图景、政策注意力水平、政策议定场和政策基调相互作用的结果。农地基本制度、外部环境以及大众媒体引导政策图景在积极与消极之间转化, 成为政策变迁的起点。受政策注意力水平影响, 政策议定场由次级系统上升到宏观系统, 配合政策基调改变, 推动政策过程发展, 最终导致农地经营政策变迁。在推进国家治理能力和治理体系现代化大背景下, 理解政策变迁过程不仅具有现象解释意义, 更可在了解变迁机制基础上, 注重新媒体和公众在决策中的作用, 提升科学决策和民主决策水平。 The purpose of this article is to discover the dynamic mechanism to stimulate the evolution of China’s rural land management policy since 1949 based on text mining and literature research. The results show that policy image transfers from positive to negative under different land tenure system, international situation and the effect of mass media. The outcome of text mining on People’s Daily reports from 1949 to 2019 finds out policy attentiveness and its nature are various in different years. What’s more, the shift of policy image and policy attentiveness combined with policy tones causes that policy venue climbs from secondary policy system to macro political system, and ultimately inspired policy change. In conclusion, policy image, policy attentiveness and its nature, policy venue and policy tones are the main factors to cause the change of rural land management policy. It needs to pay attention to the dynamics mechanism of policy evolution and perfect current household contract system.

Controlled synthesis of SrCO3 dendrites by a simple hydrothermal method

Yonggang Wang,Linlin Yang,Xiaofeng Wang,Yujiang Wang,GAORONG HAN 한양대학교 세라믹연구소 2015 Journal of Ceramic Processing Research Vol.16 No.2

In this paper, we report the controlled synthesis of SrCO3 crystals by a simple hydrothermal method without any surfactants and templates. The as-prepared samples were characterized by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). The effect of pH value, temperature, and reaction time on the formation of SrCO3 crystals was investigated. This novel route is proved to be simple and environment-friendly, which can be extended to the shape-controlled synthesis of other metal oxide nanocrystals.

연구개발·투자와 정부지원이 기업의 경영성과에 미치는 영향에 관한 실증연구 - 중국 중소제조업을 중심으로 -

왕림림 ( Linlin Wang ),장석주 ( Seogju Chang ) 전남대학교 지역개발연구소 2019 지역개발연구 Vol.51 No.1

최근 몇 년 동안 세계 금융 위기가 고조되고 많은 선진국들이 국내 제조업 활성화기 위한 정책이 시행되었다. 국가 경제에 대한 제조업의 중요성이 재확인되었다. 한편, 선진국과 신흥 개도국에서는 중소기업이 98% 이상을 차지한다. 따라서 중소제조업에 대한 연구가 특히 중요하다. 발전 중에 있는 중국 중소기업이 심각하게 위협 받고 있다. 불리한 환경에 대처하기 위해 중소제조업은 혁신적으로 새로운 경쟁 우위를 창출해야 한다. R&D 활동은 혁신의 출발점이며 기업 발전에 중요하다. 그러나 R&D 활동에는 많은 비용이 소요되며 향후에는 불확실성이 존재한다. 기업이 연구개발을 수행하고 제조업의 고도화를 장려하기 위해 정부는 관련 보조금을 기업에 제공 할 것이다. 중국의 기업은 국유기업과 비 국유기업을 구분한다. 따라서 R&D 투자가 기업의 경영성과에 미치는 영향을 확인하여 올바른 결정을 내릴 수 있어야 한다. 그러므로 본 연구는 R&D 투자와 정부지원의 효과에 대한 연구를 계속하고 있다. 본 연구의 결과는 R&D 투자와 정부지원이 기업 성과에 유의한 긍정적 영향을 미친다는 것과 R&D 투자와 기업 속성이 경영성과에 유의한 부정적 영향이 나타남을 시사한다. Because of the global financial crisis, many developed countries have implemented policies to stimulate domestic manufacturing. This study reaffirmed the importance of the manufacturing industry to the national economy. The small and medium enterprises (SMEs) play a key role in the manufacturing industry since SMEs accounted for more than 98% of the total business units in developed and emerging economies. Therefore, research on SMEs in the manufacturing industry is particularly important. However, the development of Chinese SMEs are under serious threat. Thus, it is necessary to create innovatively new competitive advantages for SMEs in the manufacturing industry to handle such adverse economic environment. R&D activities are the starting point for such innovations and an important component for enterprise development. However, R&D activities are costly and highly uncertain. Therefore the government should provide the relevant subsidies to enterprises in order to carry out R&D and promote the manufacturing industry. This study is evaluating the impact of R&D investment and government support on enterprises business performance. In addition, we distinguish Chinese enterprises between state-owned enterprises and non-state-owned enterprises, as corporate attributes might have different effects on business performance. The results of this study suggest that R&D investment and government support have a positive effect on firm performance, but corporate attributes have a significant negative impact on business performance.

Controlled synthesis and characterization of BiVO4 dendrites via a hydrothermal method

Yonggang Wang,Linlin Yang,Xiaofeng Wang,Yujiang Wang,GAORONG HAN 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.7

BiVO4 dendrites have been controllably synthesized by a hydrothermal method without any surfactants or templates. Thestructure and morphology of the obtained BiVO4 dendrites were characterized by X-ray powder diffraction, scanning electronmicroscope, transmission electron microscopy, and high-resolution transmission electron microscopy. The effect of the pHvalues, precursors, solution concentrations, reaction temperature, and reaction time on the morphology and structure of theBiVO4 dendrites was systematically studied for the first time. It is found that the morphologies of the obtained BiVO4crystallites can vary from cubic-like to dendritic shape. The BiVO4 dendrites can be successfully fabricated by thehydrothermal method at 150 oC and pH 7 when Bi2(CO3)3 and NH4VO3 were used as precursors The resultant dendriticstructure has four trunks which have ordered branches on the opposite sides of the trunks. A rational mechanism for theoriental growth of the BiVO4 dendrites is discussed. The preparation of BiVO4 dendrites with well-dened shapes may open newopportunities for wide applications of future nanodevices.