Factors affecting mobile-phone users' intention to use m-commerce in Korea & China

Xiaoyu Guo,Daihwan Min 한국IT서비스학회 2010 한국IT서비스학회 학술대회 논문집 Vol.2010 No.9

This study empirically examines factors that affect the intention to use m-commerce and the relationships among the factors. Survey data is being collected both in Korea and China. The development of mobile commerce in China is still in slower pace than Korea. This study attempts to find out the differences among the factors affecting the usage of mobile commerce in Korea and China. The result from this study would contribute to understanding people's usage behavior in the current mobile environment and suggest implications for expediting m-commerce.

Prediction of Cellulose Crystallinity in Liquid Phase Using CBM-GFP Probe

Xiaoyu Guo,Fan Yang,Huixue Liu,Yingmin Hou,Yafang Wang,Jie Sun,Xiaoyi Chen,Yanan Liu,Xianzhen Li 한국고분자학회 2019 Macromolecular Research Vol.27 No.4

Carbohydrate-binding modules (CBMs) have been developed to investigate the presence of crystalline and amorphous regions of cellulose. However, systematic and quantitative assessment of cellulose crystallinity using such non-hydrolytic fusion proteins in liquid phase has not been reported. In this work, cellulose directed CBM probes containing a green fluorescent protein (GFP) were constructed and named CG17, CG28, and CG2a. The probe binding condition was determined as incubating 30 μg/mL probes in 10 mM phosphate buffer at 30oC for 60 min. Under the optimized condition, the linear correlations between CBM probe binding capability and X-ray diffraction (XRD) crystallinity were well established. Using linear regression equations, the crystallinity of several cellulosic materials was well calculated. Amorphous component and cellulosic surface area probably had a less effect on binding capability of CG2a than that of CG17 and CG28. Therefore, crystalline-region specific probe CG2a should be an efficient tool for interpreting the crystallinity of cellulosic materials.

Concentrations of Calcium-binding Protein and Bone Gla-protein in Culture Medium and CaBP mRNA Expression in Osteoblasts of Broiler Chickens

Guo, Xiaoyu,Yan, Sumei,Shi, Binlin,Feng, Yongmiao Asian Australasian Association of Animal Productio 2011 Animal Bioscience Vol.24 No.2

This study was conducted to determine the effects of excess vitamin A on alkaline phosphatase (ALP) activity, contents of calcium-binding protein (CaBP), bone gla-protein (BGP) in culture medium and CaBP mRNA expression in chicken osteoblasts in vitro. Osteoblastic cells in the tibia from 1-day-old Arbor Acre broiler chickens were isolated using enzyme digestion. The subconfluenced cells were divided into eight treatments with six replicates in each treatment and cultured in a medium containing either vehicle or different levels of vitamin A (0, 0.2, 0.6, 1.0, 2.0, 5.0, 10.0 and $20.0\;{\mu}g$/ml), and the control received an equivalent volume of ethanol. The incubation lasted 48 h. The results showed that vitamin A down-regulated ALP activity in the culture medium as well as CaBP mRNA expression of osteoblasts in a linear dose-dependent manner (p = 0.124 and p<0.10, respectively), and suppressed the contents of BGP and CaBP in the culture medium in a quadratic dose-dependent manner (p<0.05 and p<0.10, respectively) with increasing addition of vitamin A. The addition of 0-$0.2\;{\mu}g$/ml vitamin A to the culture medium increased ALP activity, BGP and CaBP contents as well as CaBP mRNA expression compared with other groups, but positive effects of vitamin A tended to be suppressed when vitamin A was increased to $1.0\;{\mu}g$/ml, and adverse effects occurred when vitamin A was increased to 10.0-$20.0\;{\mu}g$/ml. These results implied that there was a threshold level of vitamin A inclusion beyond which inhibitory effects occurred, and the mechanism by which overdose of vitamin A reduced bone growth in chickens was probably reduced osteoblastic cell activity, and inhibited expression of CaBP mRNA and CaBP secretion.

Alpha-Hemolysin from Staphylococcus aureus Obstructs Yeast-Hyphae Switching and Diminishes Pathogenicity in Candida albicans

Yu Xiaoyu,Mao Yinhe,Li Guangbo,Wu Xianwei,Xuan Qiankun,Yang Simin,Chen Xiaoqing,Cao Qi,Guo Jian,Guo Jinhu,Wu Wenjuan 한국미생물학회 2023 The journal of microbiology Vol.61 No.2

The use of antibiotics can disrupt the body’s natural balance and increase the susteptibility of patients towards fungal infections. Candida albicans is a dimorphic opportunistic fungal pathogen with niches similar to those of bacteria. Our aim was to study the interaction between this pathogen and bacteria to facilitate the control of C. albicans infection. Alpha-hemolysin (Hla), a protein secreted from Staphylococcus aureus, causes cell wall damage and impedes the yeast–hyphae transition in C. albicans. Mechanistically, Hla stimulation triggered the formation of reactive oxygen species that damaged the cell wall and mitochondria of C. albicans. The cell cycle was arrested in the G0/G1 phase, CDC42 was downregulated, and Ywp1 was upregulated, disrupting yeast hyphae switching. Subsequently, hyphae development was inhibited. In mouse models, C. albicans pretreated with Hla reduced the C. albicans burden in skin and vaginal mucosal infections, suggesting that S. aureus Hla can inhibit hyphal development and reduce the pathogenicity of candidiasis in vivo.

EFFECT OF THIOPHENE IN BITHIAZOLE-BRIDGED SENSITIZERS ON THE PERFORMANCE OF DYE-SENSITIZED SOLAR CELLS

XIAOYU ZHANG,JIANLI HUA,JINXIANG HE,WENJUN WU,HANS AGREN,XIN LI,FULING GUO 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.5

In this paper, we have designed and synthesized four bithiazole-bridged sensitizers (BT-T2,TBT-T2, BT-T3 and TBT-T3) with triphenylamine and indoline as the donor segment andapplied them to dye-sensitized solar cells (DSSCs). For triphenylamine-based sensitizers as BT-T2 and TBT-T2, adding one thiophene unit between triphenylamine donor and bithiazolemoiety not only led to bathochromic shift of the maximum absorption and increase of molarextinction coe±cient, but also enhanced the photovoltaic conversion e±ciency from 7.12% ofBT-T2 to 7.51% of TBT-T2. But for indoline-based sensitizers as BT-T3 and TBT-T3,adding one thiophene unit between indoline donor and bithiazole moiety resulted in hypochro-matic shift instead of bathochromic shift. We employed the density functional theory (DFT)calculations to further investigate the in°uence of the thiophene unit on their optical and elec-tronic properties and photovoltaic performance of corresponding DSSC devices. Given theresults, a reasonable explanation is the introduction of thiophene unit suppressed the intramo-lecular charge transfer and charge separation in the conjugation system of indoline-based sen-sitizer, which led to the hypochromatic shift of the maximum absorption wavelength and ¯nallythe low Jsc . Since the Jsc dropped sharply from 15.26 mAcm? 2 to 4.52 mAcm? 2 , the photovoltaicconversion e±ciency decreased dramatically from 7.86% to 1.93%.

A new analytical ICCE and force prediction model for wide-row machining of free-form surface

Minglong Guo,Zhaocheng Wei,Jia Wang,Minjie Wang,Xiaoyu Wang,Shengxian Liu 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.1

Cutting force is the most intuitive reflection of various influencing factors in the milling process, which is important for improving machining quality and efficiency. For the widerow milling with flat-end mill of free-form surface, an analytical in-cut cutting edge (ICCE) algorithm is studied in detail, and overall cutting force model is further constructed. The cutter location points along tool path are discretized into small oblique planes. Taking the oblique plane machining as the new object, the relative position of flat-end mill and workpiece in five-axis machining is defined parametrically. By constructing a semi-enclosed space in which the cutting edge participates in cutting, the ICCE is directly obtained. By analyzing the cutting force of oblique plane, the cutting force model of free-form surface can be established by spatial coordinate transformation. The simulation and experiment have demonstrated the correctness and effectiveness of the proposed ICCE algorithm and force prediction model.

Recognition of Radar Emitter Signals Based on SVD and AF Main Ridge Slice

Qiang Guo,Pulong Nan,Xiaoyu Zhang,Yuning Zhao,Jian Wan 한국통신학회 2015 Journal of communications and networks Vol.17 No.5

Recognition of radar emitter signals is one of core elements in radar reconnaissance systems. A novel method based on singular value decomposition (SVD) and themain ridge slice of ambiguity function (AF) is presented for attaining a higher correct recognition rate of radar emitter signals in case of low signal-tonoise ratio. This method calculates the AF of the sorted signal and ascertains the main ridge slice envelope. To improve the recognition performance, SVD is employed to eliminate the influence of noise on the main ridge slice envelope. The rotation angle and symmetric Holder coefficients of the main ridge slice envelope are extracted as the elements of the feature vector. And kernel fuzzy cmeans clustering is adopted to analyze the feature vector and classify different types of radar signals. Simulation results indicate that the feature vector extracted by the proposed method has satisfactory aggregation within class, separability between classes, and stability. Compared to existing methods, the proposed feature recognition method can achieve a higher correct recognition rate.

Free Surface Vortex in a Rotating Barrel with Rods of Different Heights

Zhang Xiaoyue,Zhang Min,ChenWanyu,Yang Fan,Guo Xueyan 한국유체기계학회 2016 International journal of fluid machinery and syste Vol.9 No.4

A bathtub vortex above the outlet of a rotating barrel is simulated. By analyzing the Ekman layer theory, it can be found that the main flow circulation is inversely proportional to the thickness of Ekman layer. The thicker the Ekman boundary layer, the weaker the rotational strength and the shorter of the length of gas core is. According to this law, models of barriers with rods of different heights are established. The reduction of air-core length in this air entrainment vortex and weakening the strength of rotation field were achieved.

A Localization Algorithm for Underwater Wireless Sensor Networks Based on Ranging Correction and Inertial Coordination

( Ying Guo ),( Xiaoyue Kang ),( Qinghe Han ),( Jingjing Wang ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.10

Node localization is the basic task of underwater wireless sensor networks (UWSNs). Most of the existing underwater localization methods rely on ranging accuracy. Due to the special environment conditions in the ocean, beacon nodes are difficult to deploy accurately. The narrow bandwidth and high delay of the underwater acoustic communication channel lead to large errors. In order to reduce the ranging error and improve the positioning accuracy, we propose a localization algorithm based on ranging correction and inertial coordination. The algorithm can be divided into two parts, Range Correction based Localization algorithm (RCL) and Inertial Coordination based Localization algorithm (ICL). RCL uses the geometric relationship between the node positions to correct the ranging error and obtain the exact node position. However, when the unknown node deviates from the deployment area with the movement of the water flow, it cannot communicate with enough beacon nodes in a certain period of time. In this case, the node uses ICL algorithm to combine position data with motion information of neighbor nodes to update its position. The simulation results show that the proposed algorithm greatly improves the positioning accuracy of unknown nodes compared with the existing localization methods.

A flexible comb electrode triboelectric-electret nanogenerator with separated microfibers for a self-powered position, motion direction and acceleration tracking sensor

Zhu, Jianxiong,Guo, Xiaoyu,Meng, Dehuan,Cho, Minkyu,Park, Inkyu,Huang, Run,Song, Weixing The Royal Society of Chemistry 2018 Journal of Materials Chemistry A Vol.6 No.34

<P>In this paper, we report a flexible comb electrode triboelectric-electret coupling nanogenerator using a separated friction microfiber object for self-powered position, motion direction and acceleration tracking sensing and its energy harvesting. The power was generated from the coupling of the electrostatic and triboelectric effects among a separated triboelectric object, a polytetrafluoroethylene (PTFE) film and interdigital electrodes. Under an acceleration of 1 m s<SUP>−2</SUP>, we found that the corona charged PTFE film with a sliding motion reached ∼3 times more short-circuit current (<I>I</I>sc) and ∼6 times more open-circuit voltage (<I>V</I>oc) than the PTFE film without corona charges, respectively. The device can be a good self-powered acceleration tracking sensor, where the reasons were a stability voltage out during the process of separated components frictions and a numerical relationship of <I>I</I>sc with increased accelerations. Moreover, potential applications using several different separated materials such as a bulk of carbon microfibers, a finger sliding with a nylon glove, and water microdrops were used to show the energy harvesting of various friction materials and their effective contact area. It was found that a much larger contact area “finger” sliding showed a <I>V</I>oc of ∼45 V, whereas a smaller contact area “microdrop” sliding on the prototype presented a maximum peak <I>V</I>oc of ∼1.8 V.</P>