A questionnaire-based survey on the Multilingual Use of College Students in Minority Areas

Yujie Shi 대한언어학회 2020 언어학 Vol.28 No.2

Language is one of the essential means of communication that makes multilingualism has been closely related with sociolinguistics. The research of language use can provide information to teachers about learners’ needs and behaviors to the learning and teaching process and to give some support for the use of different languages. From the perspective of language life, this study investigates the multilingual use of 645 college students of foreign language college in Yanbian Korean Autonomous Prefecture through the method of literature review, questionnaire and statistical analysis to understand the linguistic situation and find out the reasons behind this situation. The study shows that students have the highest score on language use of Chinese language and language usage is affected by grade, major, ethnicity and educational background of parents. This study may contribute to enriching the relevant theories about multilingual use in minority areas abroad, providing practical experience for multilingual use in minority areas and the construction of multilingual, multicultural and harmonious language living environment.

How Inference Making Mediates the Relation Between Vocabulary Knowledge and Reading Comprehension for Chinese EFL Middle School Students

Yujie Shi 한국영어교육학회 2023 ENGLISH TEACHING(영어교육) Vol.78 No.3

This study aimed to explore the role of inference making in the relation between vocabulary knowledge (breadth and depth) and reading comprehension for 487 ninthgrade Chinese EFL students who were categorized as either struggling or adequate. Path analysis was used to examine both direct and mediated effects. The results indicated a statistically significant indirect effect of vocabulary knowledge on reading comprehension, mediated by inference making, for the entire participant group. However, there were notable differences between the struggling and adequate readers, as evidenced by distinct path diagrams. For struggling readers, the indirect effect of vocabulary breadth on reading comprehension through inference making was significant, while that of vocabulary depth was not significant. For adequate readers, both vocabulary breadth and depth directly explained reading comprehension. These results are discussed in the EFL context, encompassing assessment and instructional implications for EFL readers with varying levels of reading abilities.

Elastic buckling performance of FG porous plates embedded between CNTRC piezoelectric patches based on a novel quasi 3D-HSDT in hygrothermal environment

Yujie Zhang,Zhihang Guo,Yimin Gong,Jianzhong Shi,Mohamed Hechmi El Ouni,Farhan Alhosny Techno-Press 2023 Advances in nano research Vol.15 No.2

The under-evaluation structure includes a functionally graded porous (FGP) core which is confined by two piezoelectric carbon nanotubes reinforced composite (CNTRC) layers. The whole structure rests on the Pasternak foundation. Using quasi-3D hyperbolic shear deformation theory, governing equations of a sandwich plate are driven. Moreover, face sheets are subjected to the electric field and the whole model is under thermal loading. The properties of all layers alter continuously along with thickness direction due to the CNTs and pores distributions. By conducting the current study, the results emerged in detail to assess the effects of different parameters on buckling of structure. As instance, it is revealed that highest and lowest critical buckling load and consequently stiffness, is due to the V-A and A-V CNTs dispersion type, respectively. Furthermore, it is revealed that by porosity coefficient enhancement, critical buckling load and consequently, stiffness reduces dramatically. Current paper results can be used in various high-tech industries as aerospace factories.

Dark Septate Endophyte (DSE) Fungi Isolated from Metal Polluted Soils: Their Taxonomic Position, Tolerance, and Accumulation of Heavy Metals In Vitro

Yujie Zhang,Yan Zhang,Maojun Liu,Xiaodong Shi,Zhiwei Zhao 한국미생물학회 2008 The journal of microbiology Vol.46 No.6

To understand the possible role of the plant root associated fungi on metal tolerance, their role in the uptake of heavy metals and the potential transfer of these metal ions to the plant, three strains of dark septate endophytic (DSE) fungi were isolated from a waste smelter site in southwest China, and one strain was isolated from a non-contaminated site. According to molecular phylogenetic analysis of the ITS 1-5.8S rDNA-ITS 2 gene regions and morphological characteristics, one is identified as Exophiala pisciphila, and the other three are non-sporulating fungi under the experiment condition with the nearest phylogenetic affinities to the Thysanorea papuana strain EU041814. Tolerance and accumulation abilities of the three DSE strains for metals were investigated in liquid culture. Minimum inhibitory concentrations (MIC) of Pb, Zn, and Cd were determined. It was demonstrated that the tolerance of the DSE strains varied between metal species and strains. The E. pisciphila strain is able to accumulate lead and cadmium over 20% and 5% of dry weight of biomass, respectively. Partial of the sequestrated metals can be washed with CaCl2. Morphological and enzyme activity changes taking place in the presence of excessive Pb, Cd, and/or Zn also indicate that the mechanism of heavy metal tolerance and accumulation of the DSE strains would be a complex process. The findings indicated promising tolerance and accumulation of the DSE strains with potential values in metal cycling and restoration of soil and water system.

Interfacial performance enhancement of carbon fiber/epoxy composites by a twostep surface treatment

Jian Shi,Yuji Yamamoto,Mamoru Mizuno,Chunhong Zhu 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.1

Carbon fiber-reinforced polymer composites (CFRPs) have many features, such as lightweight, high specific strength, and excellent chemical resistance. However, the adhesion at the interface of the CFRPs, which are composed of fiber and resin, is poor. Thus, delamination and interfacial peeling occur, and the mechanical properties, such as intrinsic strength and rigidity, decrease. Fiber surface modification by plasma and silane coupling treatments has attracted much attention to improve these properties. In this study, argon and oxygen mixed gas plasma treatment was used as pretreatment to introduce hydroxyl group on the fiber surface. This method was utilized to improve the adhesion between the fiber and resin. A silane coupling treatment was conducted to bond the carbon fiber and epoxy resin by chemical covalent bonding. The effect of silane coupling treatment on the interfacial property of CFRPs was investigated. Elemental analysis of the surface modified carbon fiber was explored through energy dispersive X-ray spectrometry. The functional groups of different carbon fiber surfaces were analyzed through X-ray photoelectron spectroscopy. The wettability of the treated carbon fiber was examined with a contact angle meter. The interlaminar shear strength was determined with a short beam method.

Multiple Unbounded Positive Solutions for the Boundary Value Problems of the Singular Fractional Differential Equations

Liu, Yuji,Shi, Haiping,Liu, Xingyuan Department of Mathematics 2013 Kyungpook mathematical journal Vol.53 No.2

In this article, we establish the existence of at least three unbounded positive solutions to a boundary-value problem of the nonlinear singular fractional differential equation. Our analysis relies on the well known fixed point theorems in the cones.

Inter-server Computation Offloading and Resource Allocation in Multi-drone Aided Space-Air-Ground Integrated IoT Networks

Yongpeng Shi,Junjie Zhang,Ya Gao,Yujie Xia 한국통신학회 2022 Journal of communications and networks Vol.24 No.3

Combining mobile edge computing (MEC), themulti-drone aided space-air-ground integrated Internet of things(SAG-IoT) networks can provide ground IoT devices (GIDs) highqualitywireless access and computing services. However, the diversetasks, moving drones, and limited network resources revealgreat challenges for the task offloading and resource allocationscheme exploitation. Especially, given the restricted computationresources, how to make full use of available applications deployedon MEC servers (MECSs) to compute various types of tasks, iseven an important issue. To the best of our knowledge, it is anentirely new problem since most existing works in this line assumethat all types of applications can be deployed on one MECS so asto process various offloaded tasks. Toward this end, we presentthis paper to investigate inter-server computation offloading, resourceallocation, and drone deployment to minimize the overallcomputation overhead of all GIDs. An iteratively optimizationalgorithm is proposed which alternately utilizes heuristic greedyand successive convex approximation methods. Simulation resultsverify that, for different GID numbers, optimization schemes, andcomputing models, our devised schemes can not only significantlyreduce the overall computation overhead but also achieve optimaldecisions of computation offloading, spectrum allocation, anddrone deployment.

Cyclic Shift Based Tone Reservation PAPR Reduction Scheme with Embedding Side Information for FBMC-OQAM Systems

( Yongpeng Shi ),( Yujie Xia ),( Ya Gao ),( Jianhua Cui ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.8

The tone reservation (TR) scheme is an attractive method to reduce peak-to-average power ratio (PAPR) in the filter bank multicarrier with offset quadrature amplitude modulation (FBMC-OQAM) systems. However, the high PAPR of FBMC signal will severely degrades system performance. To address this issue, a cyclic shift based TR (CS-TR) scheme with embedding side information (SI) is proposed to reduce the PAPR of FBMC signals. At the transmitter, four candidate signals are first generated based on cyclic shift of the output of inverse discrete Fourier transform (IDFT), and the SI of the selected signal with minimum peak power among the four candidate signals is embedded in sparse symbols with quadrature phase-shift keying constellation. Then, the TR weighted by optimal scaling factor is employed to further reduce PAPR of the selected signal. At the receiver, a reliable SI detector is presented by determining the phase rotation of SI embedding symbols, and the transmitted data blocks can be correctly demodulated according to the detected SI. Simulation results show that the proposed scheme significantly outperforms the existing TR schemes in both PAPR reduction and bit error rate (BER) performances. In addition, the proposed scheme with detected SI can achieve the same BER performance compared to the one with perfect SI.

Effects of dietary salt intake restriction on blood glucose levels: a meta-analysis of crossover study

Yong Shen,Yujie Shi,Jiajing Cui,Haitao He,Shuping Ren 대한지역사회영양학회 2023 Nutrition Research and Practice Vol.17 No.3

An efficient approach to fabricate lightweight polyimide/aramid sponge with excellent heat insulation and sound absorption performance

Shunxi Song,Yujie Shi,Jiaojun Tan,Zeshi Wu,Meiyun Zhang,Sheng Qiang,Jingyi Nie,Haitang Liu 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.109 No.-

Polyimide sponges have bright prospects in the weight reduction, heat insulation, and sound absorptionequipment of aerospace, navigation, and other area due to their unique three-dimensional cellular structureand outstanding comprehensive performance. However, most polyimide sponges suffered from longand complex fabrication processes. Herein, an efficient and scalable approach, i.e. water-based foamforming, was proposed to fabricate ultralight and porous polyimide/aramid sponges (PASG). Attributedto the bubble-template nature of foam-forming, PASGs exhibit high porosity (>99%) and ultra-low density(10 mg/cm3), and possess excellent thermal and sound insulation performance with an optimum thermalconductivity of 34.89 mW/mK and noise reduction coefficient of 0.41. Besides, PASGs demonstrateoutstanding mechanical properties after 500 compression cycles. This strategy providing more possibilitiesfor developing the next generation of high-performance thermal insulation and noise reductionmaterials.