A Study on Consumer’s Behavioral Intention and Use Behavior Based on UTAUT Theory: Centered around Mobile Delivery Apps

Yonghui Zhao(Yonghui Zhao),Jia Zhao(Jia Zhao),Xiaolei Wang(Xiaolei Wang) 한국무역연구원 2022 무역연구 Vol.18 No.6

Purpose – The growth of mobile delivery apps is expanding further due to the increase in nonface- to-face consumption due to social distancing in the COVID-19 situation. It is essential to understand what factors are causing this mobile delivery app market to grow significantly. Design/Methodology/Approach – To achieve the purpose of the study, independent variables were selected by searching for prior literature on UTAUT, and a questionnaire was designed according to the situation in Korea. The survey was conducted through Google Online, and statistical analysis of the research model was conducted using SPSS 25.0. Findings – According to the results of this study, the factors that significantly influence the intention to use mobile delivery apps were Performance Expectancy (PE), Effort Expectancy (EE), Social Influence (SI), and Facilitating Conditions (FC). In addition, the result indicated that Behavioral Intention (BI) had a statistically significant effect on Use Behavior (UB). Research Implications – This study will predict the user behavior of mobile delivery apps by dealing with the technical attributes of mobile delivery apps and the influencing factors that consumers recognize. In addition, as a mobile delivery app company, it is expected to play a role in establishing the marketing direction of mobile delivery apps.

Numerical Study and Multi-objective Optimization of an Energy Absorbing Connector with Curved Plate and Aluminum Foam

Yonghui Wang,Ximei Zhai 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.1

This paper presents numerical works and multi-objective optimization of the energy absorbing connectors which was employed to dissipate blast/impact energy through curved plates and aluminum foam. Finite element models of the energy absorbing connectors under dynamic crushing load were established and validated with the impact loading tests. Then, the parametric studies were conducted to reveal the infl uences of crushing velocity, angle θ , curved plate thickness as well as length and height of aluminum foam on the energy absorbing characteristics. Increasing crushing velocity was shown to improve the absorbed energy of the connector owing to the strain rate enhancement and change of deformation mode. In addition, the absorbed energy could also be increased via increasing curve plate thickness, length and height of aluminum foam as well as decreasing angle θ . The multi-objective optimization was conducted by employing the non-dominated sorting genetic algorithm II. It was noted that the specifi c energy absorption and peak crushing force were confl icting with each other.

Galloping of steepled main cables in long-span suspension bridges during construction

Yonghui An,Chaoqun Wang,Shengli Li,Dongwei Wang 한국풍공학회 2016 Wind and Structures, An International Journal (WAS Vol.23 No.6

Large amplitude oscillation of steepled main cables usually presents during construction of a long-span bridge. To study this phenomenon, six typical main cables with different cross sections during construction are investigated. Two main foci have been conducted. Firstly, aerodynamic coefficients of a main cable are obtained and compared through simulation and wind tunnel test: (1) to ensure the simulation accuracy, influences of the numerical model's grid size, and the jaggy edges of main cable's aerodynamic coefficients are investigated; (2) aerodynamic coefficients of main cables at different wind attack angles are obtained based on the wind tunnel test in which the experimental model is made by rigid plastic using the 3D Printing Technology; (3) then numerical results are compared with wind tunnel test results, and they are in good agreement. Secondly, aerodynamic coefficients of the six main cables at different wind attack angles are obtained through numerical simulation. Then Den Hartog criterion is used to analyze the transverse galloping of main cables during construction. Results show all the six main cables may undergo galloping, which may be an important reason for the large amplitude oscillation of steepled main cables during construction. The flow structures around the main cables indicate that the characteristic of the airflow trajectory over a steepled main cable may play an important role in the galloping generation. Engineers should take some effective measures to control this harmful phenomenon due to the big possibility of the onset of galloping during the construction period.

Dynamic Crushing Behaviors of Aluminum Foam Filled Energy Absorption Connectors

Yonghui Wang,Ximei Zhai 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.1

This paper presented the numerical studies on the dynamic crushing behaviors of the aluminum foam fi lled energy absorption connectors. The fi nite element (FE) model was fi rstly constructed and the accuracy of the FE model was verifi ed by comparing the force–displacement curves from FE analyses with those from tests and analytical predictions. The numerical results revealed that the deformation mode of the connector under dynamic crushing evidently diff ered from that under quasi-static loading mainly due to the inertia eff ect. Besides, the energy absorption capacity was also improved when the dynamic crushing load was applied. Then, the parametric studies on the eff ects of crushing velocity–time history, angle between fl at plate and pleated plate as well as pleated plate thickness on the energy absorption enhancements of the connectors were conducted. Based on the numerical results, two empirical equations were derived in terms of various parameters to predict the energy absorption enhancements of aluminum foam and pleated plate, which could be employed to obtain the force–displacement functions of the connectors under dynamic crushing.

Neuroprotection of Dexmedetomidine against Cerebral Ischemia-Reperfusion Injury in Rats: Involved in Inhibition of NF-κB and Inflammation Response

Wang, Lijun,Liu, Haiyan,Zhang, Ligong,Wang, Gongming,Zhang, Mengyuan,Yu, Yonghui The Korean Society of Applied Pharmacology 2017 Biomolecules & Therapeutics(구 응용약물학회지) Vol.25 No.4

Dexmedetomidine is an ${\alpha}2$-adrenergic receptor agonist that exhibits a protective effect on ischemia-reperfusion injury of the heart, kidney, and other organs. In the present study, we examined the neuroprotective action and potential mechanisms of dexmedetomidine against ischemia-reperfusion induced cerebral injury. Transient focal cerebral ischemia-reperfusion injury was induced in Sprague-Dawley rats by middle cerebral artery occlusion. After the ischemic insult, animals then received intravenous dexmedetomidine of $1{\mu}g/kg$ load dose, followed by $0.05{\mu}g/kg/min$ infusion for 2 h. After 24 h of reperfusion, neurological function, brain edema, and the morphology of the hippocampal CA1 region were evaluated. The levels and mRNA expressions of interleukin-$1{\beta}$, interleukin-6 and tumor nevrosis factor-${\alpha}$ as well as the protein expression of inducible nitric oxide synthase, cyclooxygenase-2, nuclear factor-${\kappa}Bp65$, inhibitor of ${\kappa}B{\alpha}$ and phosphorylated of ${\kappa}B{\alpha}$ in hippocampus were assessed. We found that dexmedetomidine reduced focal cerebral ischemia-reperfusion injury in rats by inhibiting the expression and release of inflammatory cytokines and mediators. Inhibition of the nuclear factor-${\kappa}B$ pathway may be a mechanism underlying the neuroprotective action of dexmedetomidine against focal cerebral I/R injury.

Neuroprotection of Dexmedetomidine against Cerebral Ischemia-Reperfusion Injury in Rats: Involved in Inhibition of NF-κB and Inflammation Response

( Lijun Wang ),( Haiyan Liu ),( Ligong Zhang ),( Gongming Wang ),( Mengyuan Zhang ),( Yonghui Yu ) 한국응용약물학회 2017 Biomolecules & Therapeutics(구 응용약물학회지) Vol.25 No.4

Dexmedetomidine is an α2-adrenergic receptor agonist that exhibits a protective effect on ischemia-reperfusion injury of the heart, kidney, and other organs. In the present study, we examined the neuroprotective action and potential mechanisms of dexmedetomidine against ischemia-reperfusion induced cerebral injury. Transient focal cerebral ischemia-reperfusion injury was induced in Sprague-Dawley rats by middle cerebral artery occlusion. After the ischemic insult, animals then received intravenous dexmedetomidine of 1 mg/kg load dose, followed by 0.05 mg/kg/min infusion for 2 h. After 24 h of reperfusion, neurological function, brain edema, and the morphology of the hippocampal CA1 region were evaluated. The levels and mRNA expressions of interleukin-1b, interleukin-6 and tumor nevrosis factor-α as well as the protein expression of inducible nitric oxide synthase, cyclooxygenase-2, nuclear factor-κBp65, inhibitor of κBα and phosphorylated of κBα in hippocampus were assessed. We found that dexmedetomidine reduced focal cerebral ischemia-reperfusion injury in rats by inhibiting the expression and release of inflammatory cytokines and mediators. Inhibition of the nuclear factor-κB pathway may be a mechanism underlying the neuroprotective action of dexmedetomidine against focal cerebral I/R injury.

Galloping of steepled main cables in long-span suspension bridges during construction

An, Yonghui,Wang, Chaoqun,Li, Shengli,Wang, Dongwei Techno-Press 2016 Wind and Structures, An International Journal (WAS Vol.23 No.6

Large amplitude oscillation of steepled main cables usually presents during construction of a long-span bridge. To study this phenomenon, six typical main cables with different cross sections during construction are investigated. Two main foci have been conducted. Firstly, aerodynamic coefficients of a main cable are obtained and compared through simulation and wind tunnel test: (1) to ensure the simulation accuracy, influences of the numerical model's grid size, and the jaggy edges of main cable's cross section on main cable's aerodynamic coefficients are investigated; (2) aerodynamic coefficients of main cables at different wind attack angles are obtained based on the wind tunnel test in which the experimental model is made by rigid plastic using the 3D Printing Technology; (3) then numerical results are compared with wind tunnel test results, and they are in good agreement. Secondly, aerodynamic coefficients of the six main cables at different wind attack angles are obtained through numerical simulation. Then Den Hartog criterion is used to analyze the transverse galloping of main cables during construction. Results show all the six main cables may undergo galloping, which may be an important reason for the large amplitude oscillation of steepled main cables during construction. The flow structures around the main cables indicate that the characteristic of the airflow trajectory over a steepled main cable may play an important role in the galloping generation. Engineers should take some effective measures to control this harmful phenomenon due to the big possibility of the onset of galloping during the construction period.

Effect of blended protein nutritional support on reducing burn-induced inflammation and organ injury

Yu Yonghui,Zhang Jingjie,Wang Jing,Wang Jing,Chai Jiake 한국영양학회 2022 Nutrition Research and Practice Vol.16 No.5

BACKGROUND/OBJECTIVES Previous studies have reported that protein supplementation contributes to the attenuation of inflammation. Serious trauma such as burn injury usually results in the excessive release of inflammatory factors and organs dysfunction. However, a few reports continued to focus on the function of protein ingestion in regulating burn-induced inflammation and organ dysfunction. MATERIALS/METHODS This study established the rat model of 30% total body surface area burn injury, and evaluated the function of blended protein (mixture of whey and soybean proteins). Blood routine examination, inflammatory factors, blood biochemistry, and immunohistochemical assays were employed to analyze the samples from different treatment groups. RESULTS Our results indicated a decrease in the numbers of white blood cells, monocytes, and neutrophils in the burn injury group administered with the blended protein nutritional support (Burn+BP), as compared to the burn injury group administered normal saline supplementation (Burn+S). Expressions of the pro-inflammatory factors (tumor necrosis factor-α and interleukin-6 [IL-6]) and chemokines (macrophage chemoattractant protein-1, regulated upon activation normal T cell expressed and secreted factor, and C-C motif chemokine 11) were dramatically decreased, whereas anti-inflammatory factors (IL-4, IL-10, and IL-13) were significantly increased in the Burn+BP group. Kidney function related markers blood urea nitrogen and serum creatinine, and the liver function related markers alanine transaminase, aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase were remarkably reduced, whereas albumin levels were elevated in the Burn+BP group as compared to levels obtained in the Burn+S group. Furthermore, inflammatory cells infiltration of the kidney and liver was also attenuated after burn injury administered with blended protein supplementation. CONCLUSIONS In summary, nutritional support with blended proteins dramatically attenuates the burn-induced inflammatory reaction and protects organ functions. We believe this is a new insight into a potential therapeutic strategy for nutritional support of burn patients.

Gas–Liquid Flow Characteristics and Performance Optimization of Industrial Downflow Jet Loop Reactor Based on Computational Fluid Dynamics

Li Yonghui,Wang Jiayi,Lu Chao,Wang Sheng,Dong He 한국화학공학회 2024 Korean Journal of Chemical Engineering Vol.41 No.6

The fl uid dynamics and structural enhancements of a novel industrial jet loop reactor (JLR) were investigated through Computational Fluid Dynamics (CFD) simulations. The arc-shaped trajectory of W-shaped baffl e facilitated the continued circulation of a substantial portion of the fl uid, resulting in increased total gas holdup, axial liquid velocity, and overall liquid circulation volume. Compared to similar reactors with a round baffl e, the JLR increased gas holdup from 13.01% to 14.04% and liquid circulation volume from 4.67 m 3 /s to 4.94 m 3 /s; the W-shaped baffl es increased gas holdup and liquid circulation volume by approximately 8% and 7%, respectively. Additionally, the study explored the infl uence of various structural parameters such as nozzle diameter, nozzle quantity, draft tube length and shape. Optimal structural parameters were determined based on this analysis. The insights and design proposed in this work will provide valuable perspectives and further understanding for reactor scale-up in industrial applications, serving as a guide for geometric and fl ow pattern functionalities.

Particle resolved CFD simulation on vapor-phase synthesis of vinyl acetate from ethylene in fixed-bed reactor

Yonghui Li,Mingkai Wang,Xingxing Cao,Zhongfeng Geng 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.5

The synthesis of vinyl acetate (VAc) from ethylene is a strongly exothermic reaction that might easily cause catalyst deactivation and reduce selectivity of VAc. Research at the bed scale helps to improve the conversion of C2H4 and the selectivity of VAc. In this study, the discrete element method (DEM) was used to construct a fixed-bed structure model via simulating the filling process of catalyst particles in the reactor. The inlet section of a reaction tube was studied, and its length was 10 cm. The temperature distribution, and the effects of particles size, inlet velocity, inlet temperature and the feed ratio of C2H4 to O2 on the reaction process were studied. Simulated results show that the bed temperature gradually increased from the wall to the center, and the temperature gradient gradually decreased along the radial direction. The maximum temperature was 438.68 K and the temperature difference from the inlet temperature was 5.54 K. Comparing the composite particle packed bed with the single particle size packed bed, the composite packed bed has higher vinyl acetate selectivity. Increasing inlet velocity from 1.5m/s to 3.5m/s, the selectivity of vinyl acetate increased from 91.71% to 92.60%. Adding an inert gas to the feed gas can increase the oxygen concentration and reduce the explosion interval of C2H4, the conversion of C2H4 and the selectivity of vinyl acetate increased.