STABLE AND ROBUST ℓ_p-CONSTRAINED COMPRESSIVE SENSING RECOVERY VIA ROBUST WIDTH PROPERTY

Yu, Jun,Zhou, Zhiyong Korean Mathematical Society 2019 대한수학회지 Vol.56 No.3

We study the recovery results of ${\ell}_p$-constrained compressive sensing (CS) with $p{\geq}1$ via robust width property and determine conditions on the number of measurements for standard Gaussian matrices under which the property holds with high probability. Our paper extends the existing results in Cahill and Mixon from ${\ell}_2$-constrained CS to ${\ell}_p$-constrained case with $p{\geq}1$ and complements the recovery analysis for robust CS with ${\ell}_p$ loss function.

중국 크로스보더 이커머스 플랫폼의 지속적 이용에 영향을 미치는 품질요인에 관한 연구

Yu Jun,유재현 한국인터넷전자상거래학회 2023 인터넷전자상거래연구 Vol.23 No.1

The COVID-19 pandemic has caused a surge in online shopping, making cross-border e-commerce a growing trend in global import and export trade. This type of e-commerce provides many opportunities for small and medium-sized enterprises to participate in international trade and helps to enhance national economic competitiveness. Despite existing research on sub-factors, there is a lack of research on factors affecting consumers' continuance use intention of cross-border e-commerce platforms. This study aimed to fill that gap by applying the IS Success Theory to analyze the influence of cross-border e-commerce quality factors on continuance use intention. An empirical analysis was conducted using data collected from an online survey of 276 people with experience using Tmall Global, a Chinese cross-border e-commerce platform. The results showed that system quality, information quality, and service quality positively affected consumer trust and satisfaction, which in turn had a positive effect on continuance use intention. The study's implications suggest that improving service quality, providing accurate and diverse information, and maintaining a stable system are essential for increasing consumer trust, satisfaction, and continuance use intention.

Inhibitory Effects of Garcinia cambogia Extract on CYP2B6 Enzyme Activity

Yu, Jun,Choi, Min,Park, Jong,Rehman, Shaheed,Nakamura, Katsunori,Yoo, Hye Georg Thieme Verlag KG 2017 Planta medica Vol.83 No.11

<B>Abstract</B><P>This study assessed the inhibitory effects of Garcinia cambogia extract on the cytochrome P450 enzymes in vitro. G. cambogia extract was incubated with cytochrome P450 isozyme-specific substrates in human liver microsomes and recombinant CYP2B6 isozyme, and the formation of the marker metabolites was measured to investigate the inhibitory potential on cytochrome P450 enzyme activities. The results showed that G. cambogia extract has significant inhibitory effects on CYP2B6 activity in a concentration-dependent manner. Furthermore, the inhibition was potentiated following preincubation with NADPH, indicating that G. cambogia extract is a time-dependent inhibitor of CYP2B6. Meanwhile, hydroxycitric acid, the major bioactive ingredient of G. cambogia extract, did not exhibit significant inhibition effects on cytochrome P450 enzyme activities. G. cambogia extract could modulate the pharmacokinetics of CYP2B6 substrate drugs and lead to interactions with those drugs. Therefore, caution may be required with respect to concomitant intake of dietary supplements containing G. cambogia extract with CYP2B6 substrates.</P>

O2O 서비스 구전의도에 영향을 미치는 요인에 대한 연구: 중국 스마트 오더 서비스를 중심으로

Yu Jun,유재현 한국정보시스템학회 2023 情報시스템硏究 Vol.32 No.2

Purpose The aim of this study is to investigate how system quality, privacy concerns, and usefulness impact user satisfaction and word-of-mouth intention towards smart order services among Chinese consumers. The study also seeks to provide both theoretical and practical implications based on the findings. Design/methodology/approach This study conducted an empirical study on Chinese consumers through an online survey on 274 users of smart order service in China. To analyze the data, frequency analysis, reliability analysis, and confirmatory factor analysis were performed using SPSS 26.0 and AMOS 26.0 statistical programs, and structural equation model was used for hypothesis testing. Findings The study results are as follows. First, system quality was found to have a positive effect on usefulness and user satisfaction. Second, privacy concerns were found to have a positive effect on user satisfaction, but not on usefulness. Third, user satisfaction was found to have a positive effect on consumers' word-of-mouth intention of the smart order service. Finally, mediating effects were found between system quality and user satisfaction through usefulness, as well as between system quality, perceived privacy concern, and usefulness through user satisfaction.

Promoter methylation of the Wnt/β‐catenin signaling antagonist <i>Dkk‐3</i> is associated with poor survival in gastric cancer

Yu, Jun,Tao, Qian,Cheng, Yuen Y.,Lee, Kwan Y.,Ng, Simon S. M.,Cheung, Kin F.,Tian, Linwei,Rha, Sun Y.,Neumann, Ulf,Rö,cken, Christoph,Ebert, Matthias P. A.,Chan, Francis K. L.,Sung, Joseph J. Y. Wiley Subscription Services, Inc., A Wiley Company 2009 Cancer Vol.115 No.1

<P><B>Abstract</B></P><P><B>BACKGROUND:</B></P><P>Abnormal activation of the Wnt/β‐catenin signaling pathway is common and critical in the pathogenesis of digestive cancers. In this study, the authors investigated the promoter methylation of the dickkopf homolog 3 gene <I>Dkk‐3</I> in these cancers and its prognostic significance in gastric cancer.</P><P><B>METHODS:</B></P><P><I>Dkk‐3</I> methylation was assessed in 173 patients with gastric cancers (including 104 patients who were followed for up to 4090 days) and in 128 patients with colorectal cancer. Cell growth was evaluated by using a colony‐formation assay. For survival analyses, the authors used Kaplan‐Meier plots, the log‐rank test, and Cox proportional regression.</P><P><B>RESULTS:</B></P><P><I>Dkk‐3</I> was silenced or down‐regulated in 12 of 17 gastric cancer cell lines (70.6%) and in 3 of 9 colon cancer cell lines (33.3%). The loss of gene expression was associated with promoter methylation, which could be restored by demethylating agents. Ectopic expression of <I>Dkk‐3</I> suppressed colony formation. Moreover, methylation of <I>Dkk‐3</I> was detected in 117 of 173 primary gastric tumors (67.6%) and in 67 of 128 colorectal tumors (52.3%). The clinical significance and the prognostic value of <I>Dkk‐3</I> methylation also were examined in 104 gastric cancers and in 84 colorectal cancers. Multivariate analysis indicated that <I>Dkk‐3</I> methylation was associated significantly and independently with poor disease survival (relative risk, 2.534; 95% confidence interval, 1.54–4.17; <I>P</I> = .002) in gastric cancer, but not in colorectal cancer. Kaplan‐Meier survival curves revealed that patients who had <I>Dkk‐3</I> methylated gastric cancers had a significantly shorter survival (median, 0.76 years) compared with patients who did not have <I>Dkk‐3</I> methylation (median, 2.68 years; <I>P</I> < .0001; log‐rank test).</P><P><B>CONCLUSIONS:</B></P><P>Epigenetic silencing of the <I>Dkk‐3</I> gene by promoter methylation was a common event in gastric cancer and was associated with a poor outcome in such patients. Cancer 2009. © 2008 American Cancer Society.</P>

Catalytic chlorination of methylphenyldichlorosilane with gaseous chlorine to chlorinated methylphenyldichlorosilanes over Lewis acids

Yujun Fu,Hengbo Yin,Yiqian Jiang,Lingqin Shen,Yonghai Feng,Aili Wang 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.3

Methylchlorophenyldichlorosilane (MeClPhSiCl2) and methyldichlorophenyldichlorosilane (MeCl2Ph-SiCl2) were synthesized by the catalytic chlorination of methylphenyldichlorosilane (MePhSiCl2) withCl2 over Lewis acid catalysts. The catalytic activities of Lewis acid catalysts were in an order ofFeCl3 > SbCl5 > AlCl3 > SnCl4. However, FeCl3 also highly catalyzed the cleavage of chlorophenyl–siliconbond to form chlorobenzene. At a low mole ratio of SbCl5 to MePhSiCl2 of 1.4 × 10-5:0.45, the yield ofMeClPhSiCl2 was around 60% after reacting at 25–100 8C for 15–20 h. At a high mole ratio of1.4 × 10-4:0.45, the yield of MeCl2PhSiCl2 reached 44% after reacting at 80–100℃ for 20 h.

Charge separation properties of (BiO)2CO3/BiOI heterostructures with enhanced solar-driven photocatalytic activity

Yujun Si,Jianzhang Li,Junbo Zhong,Jun Zeng,Shengtian Huang,Wei Yuan,Minjiao Li,Jie Ding 한국물리학회 2016 Current Applied Physics Vol.16 No.3

(BiO)2CO3/BiOI heterojunctions were prepared in-situ by a pore impregnating method using HI aqueous solution. The specific surface area, structure, morphology, and charge separation properties of the heterostructures prepared were characterized by BrunauereEmmetteTeller (BET) method, X-ray diffraction (XRD), scanning electron microscopy (SEM), and surface photovoltage (SPV) spectroscopy, respectively. The active species were investigated using scavengers. The photocatalytic activities of (BiO)2CO3/BiOI heterojunctions towards discoloration of rhodamine B (RhB) under simulated sun light irradiation were evaluated. Benefiting from enhanced charge separation efficiency, the composite photocatalysts exhibit higher photocatalytic performance than the pure BiOI. Finally, the possible reason was discussed.

A Novel MAC Protocol Exploiting Concurrent Transmissions for Massive LoRa Connectivity

Yujun Hou,Zujun Liu,Dechun Sun 한국통신학회 2020 Journal of communications and networks Vol.22 No.2

Among variant low-power wide area networks (LPWAN),LoRa is one of the most promising and is extensively deployedworldwide because of its satisfactory performance and relativelylow cost. In the foreseen future, various internet of things (IoT)applications are required to sustain connectivity for massive enddevices. Massive connectivity challenges the LoRaWAN networkbased on ALOHA medium access control (MAC) protocol due tosevere collisions under high traffic loads. To solve this problem,we first dissect the principles and characteristics of LoRa physicallayer. And it suggests that the capture effect among the signalswith the same spreading factor (SF) and different SFs can beadequately leveraged to improve performance. Based on the captureeffect, we develop a new receiver structure that enables thesuperposed LoRa signals with different odd/even SFs to be demodulatedsimultaneously. A suitable novel MAC protocol exploitingsuch concurrent transmissions is further presented. Simulationsverify that, through utilizing the capture effect, the proposed protocolcan partly tackle the collisions due to numerous access attempts,which results in enhancing the throughput compared toLoRaWAN. These results show that the proposed scheme is compliantwith the requirement of IoT applications with massive connectivity.

Hybrid Particle Swarm Optimization Algorithm for Job- Shop Robotic Manufacturing Cell Scheduling Problems

Yujun Yang,Chuanze Long,Qiongjun Zeng 한국생산제조학회 2014 한국생산제조시스템학회 학술발표대회 논문집 Vol.2014 No.9(2)

Classification of nonoscillatory solutions of second order self-adjoint neutral difference equations

Yujun Liu,Zhaoshuang Liu,Zhenguo Zhang 한국전산응용수학회 2004 Journal of applied mathematics & informatics Vol.14 No.-

Consider the second order self-adjoint neutral difference equation of form 4(an|4(xn − pnxn)|sgn4(xn − pnxn)) + f(n, xgn) = 0. In this paper, we will give the classification of nonoscillatory solutions of the above equation; and by the fixed point theorem, we present some existence results for some kinds of nonoscillatory solutions of the equation.