Design of Single-Phase Electrical Spring Based on PR Controller and Critical Load Current Feedback

Wei Yi,Zhao ChaoHui,Duan YuBin 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.6

According to the characteristics of fast and accurate voltage regulation of single-phase electrical spring (ES), a critical load current feedback control strategy considering grid voltage is proposed. Taking pure resistive loads as an example, the S-domain mathematical model of ES is established. Based on this, the design method is described in detail. Aiming at the voltage fl uctuation of power grid aff ects the regulation precision of ES, the feedforward control of grid voltage is proposed. Through the equivalent transformation of control block diagrams, the feedforward transfer function of grid voltage which can eff ectively eliminate the infl uences of grid voltage on the regulation precision of ES is deduced. Finally, the eff ectiveness and correctness of the proposed control method is verifi ed by experiments

How Perceived Price Discount Influence on the Impulsive Consumption in the Context of Online Limited-Time Promotion: Moderating Effect of Perceived Time Pressure

Weiyi Luo,이영찬 한국정보시스템학회 2022 情報시스템硏究 Vol.31 No.4

Purpose In the current environment of online shopping, the cost for consumers to obtain the information they need is decreasing, and the price of products is becoming more transparent, leading to increased price competition among enterprises for similar products. Given the widespread usage of limited-time promotion as a marketing method for enterprises in the context of e-commerce, it is great meaning to study and reveal the internal influence mechanism of limited-time promotion on consumers’ impulsive consumption. Design/methodology/approach Based on the S-O-R theory, this study constructs a model of consumers’ impulsive consumption in the context of e-commerce from the perspective of perceived price discount, with evoking sense and pleasure as mediating variables and perceived time pressure as moderating variables. Findings The results show that perceived price discount has a significant positive impact on evoking sense and pleasure. Evoking sense has a significant positive impact on pleasure. Both evoking sense and pleasure have a significant positive impact on consumers’ impulsive consumption. Meanwhile, perceived time pressure plays a significant moderating role between perceived price discount and evoking sense, between perceived price discount and pleasure, and between evoking sense and consumers’ impulsive consumption. Finally, based on the above findings, this study provides effective suggestions for e-commerce participants in the formulation of limited-time promotion strategies.

Recresistance of high-toughness grains to cleavage cracking in a polycrystalline, brittle material

Weiyi Lu,Jin Chen,Srinivas S. Chakravarthula,Falgun B. Surani,Yu Qiao 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.10

As a cleavage crack propagates through a field of randomly oriented grains, due to the variation in local fracture resistance, the crack front advance is nonuniform. The crack would first penetrate into the low-toughness grains, leaving the high-toughness ones behind its front. In this article, the barrier effect of the high-toughness grains is investigated in considerable detail through a computational analysis. The dominant factors are the grain size and the effective content of high-toughness grains.

Multi-objectives fuzzy models for designing 3D trajectory in horizontal wells

Weiyi Qian,Enmin Feng 한국전산응용수학회 2004 Journal of applied mathematics & informatics Vol.15 No.-

In this paper, multi-objective models for designing 3D trajec-tory of horizontal wells are developed in a fuzzy environment. Here, theobjectives of minimizing the length of the trajectory and the error of entrytarget point are fuzzy in nature. Some parameters, such as initial value,end value, lower bound and upper bound of the curvature radius, tool-face angle and the arc length of each curve section, are also assumed tobe vague and imprecise. The impreciseness in the above objectives havebeen expressed by fuzzy linear membership functions and that in the aboveparameters by triangular fuzzy numbers. Models have been solved by thefuzzy non-linear programming method based on Zimmermann [1] and Leeand Li [2]. Models are applied to practical design of the horizontal wells.Numerical results illustrate the accuracy and eciency of the fuzzy models.

Rational Design and Molecular Engineering of Peptide Aptamers to Target Human Pancreatic Trypsin in Acute Pancreatitis

Weiyi Shao,Wenxian Zhu,Yanhua Wang,Jingwei Lu,Ge Jin,Yixin Wang,Wenli Su 한국생물공학회 2016 Biotechnology and Bioprocess Engineering Vol.21 No.1

Human pancreatic trypsin (hPT) is an established target for acute pancreatitis (AP) therapeutics. Here, a bioinformatics protocol of protein docking, peptide refinement, dynamics simulation and affinity analysis was described to perform rational design and molecular engineering of hPT peptide aptamers. Protein docking was employed to model the intermolecular interactions between hPT and its cognate inhibitory protein, the human pancreatic trypsin inhibitor (hTI). A number of peptide fragments were cut out from the interaction sites of docked hPT–hTI complexes, from which a decapeptide fragment 13LNGCTLEYRP22 was found to exhibit potent inhibition against hPT (Ki = 5.3 ± 0.8 μM). We also carried out alanine scanning and virtual mutagenesis to systematically examine the independent contribution of peptide residues to binding affinity, and the harvested knowledge were then used to guide modification and optimization of the decapeptide fragment. Subsequently, inhibition studies of nine promising candidates against recombinant hPT were conducted, from which four samples were successfully identified to have high or moderate potency (Ki < 10 μM). In particular, the peptides LQVCTLEYCN and LQICTLEYCT were found to inhibit hPT activity significantly (Ki = 0.23 ± 0.04 and 0.85 ± 0.18 μM, respectively). Structural analysis of hPT– peptide complex systems unraveled diverse chemical interactions such as hydrogen bonds, salt bridges and hydrophobic forces across the complex interfaces.

A Theoretical Study on the Mechanism of Methylation of N-methylaniline with CO2 and Silyl Hydrides

Weiyi Li,김찬경 대한화학회 2017 Bulletin of the Korean Chemical Society Vol.38 No.1

The mechanism of methylation of N-methylaniline with CO2 and the phenylsilane (PhSiH3) was studied using density functional theory (DFT) at the M05-2X(THF, SMD)/6-311++G**//M05-2X/6-31G* level. The calculations show that the three-component reaction takes place from the reduction of CO2 with PhSiH3, forming the formoxysilane (FOS) species. This hydrosilylation step requires the highest activation free energy barrier (41.6 kcal/mol), and thus can be regarded as the rate-determining step (RDS) for the entire reaction. Once the FOS species is formed, its subsequent formylation with the amine to formamide (FA) species and the two successive reductions of the FA species to the desired methylamine (MA) product are easy to proceed. Furthermore, our calculations show that 1,3-diphenyldisiloxan-1-ol (PhSiH2OSiHOHPh) is together formed with the product MA. The Si–H bond activity in PhSiH2OSiHOHPh is higher than that in reactant PhSiH3 and intermediate phenylsilanol (PhSiH2OH). Thus, there exists a product catalysis as the activation free energy barrier for the FOS species formation is lowered to 36.9 kcal/mol when this species is used as a reducing agent.

Consumer Vulnerability Scale Development and Empirical Validation: Focused on the Online Irrational Consumption

Weiyi Luo(라위의),Young-Chan Lee(이영찬) 한국아시아학회 2022 아시아연구 Vol.25 No.4

최근 많은 학자들은 소비자 행동 연구 분야에 취약성 개념을 도입하고 이를 측정하기 위한 척도를 개발하고 있다. 그러나 기존의 소비자 취약성 척도는 일반적인 소비의 맥락 또는 특정한 맥락 중 하나를 암시하여 개발하였기 때문에 불합리한 온라인 소비 맥락에서 소비자 취약성을 효과적으로 측정하기에는 한계가 많다. 이에 본 연구에서는 심층 인터뷰와 전문가 간담회를 통해 온라인 소비자 취약성의 척도를 개발하고 검증하였다. 개발 척도의 1차 요인모형과 2차 요인모형은 각각 탐색적 요인분석과 확인적 요인분석을 통해 검증하였다. 분석결과 1차 요인모형에서는 제품 홍보, 플랫폼 보증, 상품 지식, 마케팅 압박, 사회적 압박, 시간 압박, 정서적 스트레스, 구매력과 식별력 등 9가지 요인이 도출되었다. 그리고 2차 요인모형에서는 무지 취약성과 무능력 취약성의 2가지 요인이 도출되었다. 또한 소비자의 비합리적인 온라인 소비 행동 중 충동 소비는 주로 무능력 취약성에 영향을 받는 반면, 맹목 소비는 주로 무지 취약성에 영향을 받는 것으로 나타났다. 또한 구조방정식 모형을 이용하여 온라인 맹목 소비는 제품 홍보, 플랫폼 보증, 상품 지식, 시간 압박의 4가지 차원에 의해 영향을 받고, 온라인 충동 소비는 마케팅 압력, 사회적 압력, 시간적 압력, 정서적 스트레스, 구매력 및 식별력 등 6가지 차원에 의해 영향을 받는다는 것을 확인했다. 본 연구는 전자상거래 기업들이 소비자들의 비합리적인 온라인 소비행동을 분석하는데 실무적인 시사점을 제공할 뿐만 아니라 온라인 소비자 행동 분석에 대한 향후 심층적인 연구를 수행하는데 유용한 학술적 시사점을 갖는다. In recent years, scholars at home and abroad have introduced the concept of vulnerability into the research field of consumer behavior and have developed the scales of consumer vulnerability. However, the existing scales of consumer vulnerability have been developed in allusion to the context of general consumption or one of its specific contexts, and it is difficult to adopt the existing scales to effectively measure the consumer vulnerability in the context of online irrational consumption. In view of this, this study extracted and purified the scale of online consumer vulnerability through in-depth interview and expert conference. Meanwhile, the first-order factor model and the second-order factor model of the scale were verified by exploratory factor analysis and confirmatory factor analysis. The results show that the first-order factor model of the scale includes 9 factors: product publicity, platform guarantee, commodity knowledge, marketing pressure, social pressure, time pressure, emotional stress, purchasing power and discernibility; and the second-order factor model of the scale includes 2 factors: ignorance vulnerability and inability vulnerability. Based on structural equation model, this study has verified that consumers’ online blind consumption can be significantly affected by 4 dimensions: product publicity, platform guarantee, commodity knowledge and time pressure, while consumers’ online impulsive consumption can be significantly affected by 6 dimensions: marketing pressure, social pressure, time pressure, emotional stress, purchasing power and discernibility. Additionally, consumers’ behavior of online impulsive consumption is mainly influenced by their inability vulnerability, while consumers’ behavior of online blind consumption is mainly influenced by their ignorance vulnerability.

Post-fire Load-carrying Properties of a Reinforced Concrete Beam Supporting Column Transfer Structure Joint Unit

Weiyi Kong,Chuanguo Fu,Weiqing Liu 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.2

According to the characteristics of a reinforced concrete beam supporting column transfer structure, two types of full-size beam supporting column transfer structure joints are designed, and the post-fire residual mechanical behavior is tested. We observe the deformation and crack propagation of joint specimens under load, construct the load-deflection curve, record the post-fire residual strength and analyze the failure mode. The results show that longer exposure to high temperature is correlated with a smaller residual capacity of the joint units. When the specimens reach the ultimate bearing capacity, cracks form in the A-type joint unit specimens that are aligned with the central axis of the supported column, and several vertical cracks appear in the core area of the joint. The cracks of the B-type joint unit arise primarily on the compression side of the supported column, and many prominent inclined cracks arise in the core area of the joint that extend from the bottom to the compression zone of the transfer beam. Therefore, for structures with a bearing column girder transfer floor, the influence of the change of the internal force distribution on the post-fire load-bearing performance caused by the arrangement of the column should be considered.

Examining the moderating effect of perceived value on continuous intention to use mobile instant messaging service

Weiyi Luo(라위의),Young-Chan Lee(이영찬) 한국인터넷전자상거래학회 2017 인터넷전자상거래연구 Vol.17 No.6

With the fast development and wide spread adoption of mobile instant messaging (MIM) service, determining which factors significantly impact customer’s continuance intention is very important for MIM providers. To better understand this phenomenon, in this study, we have integrated the construct of interaction and network externalities as independent variables. Interaction includes application interaction and social interaction; meanwhile, Network externalities include direct externalities (referent network size) and indirect externalities (perceived complementarity). The results of this study show that all these independent variables have a significant influence on overall customer satisfaction. Furthermore, from the perspective of network externalities, perceived complementarity is the only antecedent that has an impact on perceived value. Finally, the moderating effect of perceived value on the relationship between satisfaction and continuance intention is verified in this study. When perceived value is high, even low satisfied customers are more likely to continue using MIM service than high satisfied customers, who have low perceived value.

Impact response of steel-concrete composite panels: Experiments and FE analyses

Weiyi Zhao,Quanquan Guo,Xuqiang Dou,Yao Zhou,Yinghua Ye 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.26 No.3

A steel-concrete composite (SC) panel typically consists of two steel faceplates and a plain concrete core. This paper investigated the impact response of SC panels through drop hammer tests and numerical simulations. The influence of the drop height, faceplate thickness, and axial compressive preload was studied. Experimental results showed that the deformation of SC panels under impact consists of local indentation and overall bending. The resistance of the panel significantly decreased after the local failure occurred. A three-dimensional finite element model was established to simulate the response of SC panels under low-velocity impact, in which the axial preload could be considered reasonably. The predicted displacements and impact force were in good agreement with the experimental results. Based on the validated model, a parametric study was conducted to further discuss the effect of the axial compressive preload.