Dual Mediating Effects of Academic Self-Efficacy and Hope in the Link Between Conscientiousness and Academic Performance in College Students

Jianan Li,이창식 사단법인 한국융합기술연구학회 2023 아시아태평양융합연구교류논문지 Vol.9 No.11

As the higher education scale is continuously growing, academic competition among students is fierce and how to improve their academic performance efficiently is a heated problem. This study intended to solve this problem and aimed to uncover factors that influenced the academic performance of college students. Through dual mediating analysis, whether academic self-efficacy and hope double mediate the path via conscientiousness and academic performance will be tested. The study subjects were sampled using a purposive approach from two colleges in Guangzhou city of China, and data were collected with a questionnaire survey. The questionnaires was designed to collect data regarding conscientiousness, academic self-efficacy, hope, and academic performance and 400 results were collected. For research tools, SPSS ver.25 and PROCESS macro ver.4.2 were used. And frequency analysis, reliability analysis, correlation analysis, and dual mediation effect analysis were applied for analyzing data. Model number 6 of SPSS PROCESS macro was utilized to figure out the dual mediating effect. As the result of current study, firstly, there were positive correlations between conscientiousness, academic self-efficacy, hope, and academic performance. Secondly, the dual mediating effect analysis indicated that academic self-efficacy and hope double mediated the path via conscientiousness and academic performance, which showed a full mediation effect. It was assured that conscientiousness positively affected academic performance through academic self-efficacy and hope. This result was vital as it not only confirmed the dual mediation effect of academic self-efficacy and hope in the link between conscientiousness and academic performance, but also implied that it was significant to improve academic performance by designing effective intervention programs. These programs should make well use the findings that academic self-efficacy and hope combined contributed to better academic performance.

Full-scale testing on the flexural behavior of an innovative dovetail UHPC joint of composite bridges

Jianan Qi,Zhao Cheng,Jingquan Wang,Yutong Zhu,Wenchao Li 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.75 No.1

This paper presents a full-scale experimental test to investigate the flexural behavior of an innovative dovetail ultra-high performance concrete (UHPC) joint designed for the 5th Nanjing Yangtze River Bridge. The test specimen had a dimension of 3600 × 1600 × 170 mm, in accordance with the real bridge. The failure mode, crack pattern and structural response were presented. The ductility and stiffness degradation of the tested specimens were explicitly discussed. Test results indicated that different from conventional reinforced concrete slabs, well-distributed cracks with small spacing were observed for UHPC joint slabs at failure. The average nominal flexural cracking strength of the test specimens was 7.7 MPa, signifying good crack resistance of the proposed dovetail UHPC joint. It is recommended that high grade reinforcement be cooperatively used to take full advantage of the superior mechanical property of UHPC. A new ductility index, expressed by dividing the ultimate deflection by flexural cracking deflection, was introduced to evaluate the post-cracking ductility capacity. Finally, a strut-and-tie (STM) model was developed to predict the ultimate strength of the proposed UHPC joint.

Wake vortex interaction effects on energy extraction performance of tandem oscillating hydrofoils

Jianan Xu,Hongyu Sun,Songlin Tan 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.9

An energy extracting technology based on tandem oscillating hydrofoils from flow field is presented in this paper. Numerical simulation were performed to optimize the spatial arrangement for tandem oscillating hydrofoils, the position of the downstream hydrofoil relative to the wake vortex shed by the upstream hydrofoil is seen as critical. Optimized position of the two hydrofoils improves the energy extraction performance through positive interactions between the downstream hydrofoil and the wake vortices of the upstream hydrofoil, and the highest energy extraction efficiency reaches 53.8%. The downstream hydrofoil has a slight impact on the energy extraction performance of the upstream hydrofoil, and the contribution from the upstream hydrofoil is usually slightly inferior to the single hydrofoil results. Leading edge vortex (LEV) is formed and shed from the upstream hydrofoil, which is seen as critical in the energy transformation between the fluid and the energy extraction device. For different reduced frequencies, the energy extraction of a single hydrofoil is heavily influenced by the dynamics of vortex forming and shedding. The investigation was also undertaken over a wide range of kinematic parameters, including hydrofoil separation distance and reduced frequency. Results reveal that energy extraction of tandem oscillating hydrofoils shows better performance than a single hydrofoil for optimal reduced frequency and suitable hydrofoil separation distance.

Enhanced Acetoin Production by Serratia marcescens H32 Using Statistical Optimization and a Two-stage Agitation Speed Control Strategy

Jianan Sun,Liaoyuan Zhang,Ben Rao,Yunbin Han,Ju Chu,Jiawen Zhu,Yaling Shen,Dong-Zhi Wei 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.3

Enhanced acetoin production was carried out by Serratia marcescens H32. First, medium compositions were optimized statistically for shake flask fermentations to produce acetoin. Sucrose and corn steep liquor powder (CSLP) were identified as the most significant factors by Plackett–Burman design. The path of steepest ascent and response surface methodology were then employed to determine the optimal concentrations of the two factors. Acetoin yield was up to 41.5 g/L in flask fermentations using the optimized medium. Furthermore, the optimal medium was used to conduct fermentation experiments in a 3.7-L bioreactor. The influences of different agitation speeds on acetoin production were investigated. Based on a process analysis, a two-stage agitation speed control strategy was proposed, in which the agitation speed was controlled at 700 rpm during the first 8 h and then switched to 600 rpm. A relatively high acetoin concentration (44.9 g/L)and high acetoin productivity (1.73 g/L/h) were achieved by applying this strategy. Fed-batch fermentation based on the two-stage agitation speed control strategy was performed,and a maximum acetoin concentration of 60.5 g/L with productivity of 1.44 g/L/h was achieved. Enhanced acetoin production was carried out by Serratia marcescens H32. First, medium compositions were optimized statistically for shake flask fermentations to produce acetoin. Sucrose and corn steep liquor powder (CSLP) were identified as the most significant factors by Plackett–Burman design. The path of steepest ascent and response surface methodology were then employed to determine the optimal concentrations of the two factors. Acetoin yield was up to 41.5 g/L in flask fermentations using the optimized medium. Furthermore, the optimal medium was used to conduct fermentation experiments in a 3.7-L bioreactor. The influences of different agitation speeds on acetoin production were investigated. Based on a process analysis, a two-stage agitation speed control strategy was proposed, in which the agitation speed was controlled at 700 rpm during the first 8 h and then switched to 600 rpm. A relatively high acetoin concentration (44.9 g/L)and high acetoin productivity (1.73 g/L/h) were achieved by applying this strategy. Fed-batch fermentation based on the two-stage agitation speed control strategy was performed,and a maximum acetoin concentration of 60.5 g/L with productivity of 1.44 g/L/h was achieved.

Current Progress of Studies of Coronary CT for Risk Prediction of Major Adverse Cardiovascular Event (MACE)

Jianan Zheng,Bin Lu 한국심초음파학회 2021 Journal of Cardiovascular Imaging (J Cardiovasc Im Vol.29 No.4

Cardiovascular disease is a serious threat to human health, and early risk prediction of major adverse cardiovascular event in people suspected of coronary heart disease can help guide prevention and clinical decisions. Coronary computed tomography (CT) is a useful imaging tool for evaluation of coronary heart disease, and its ability to reflect coronary atherosclerosis shows potential value for risk prediction. In recent years, various new techniques and studies of coronary CT have emerged for risk prediction of major adverse cardiovascular event in people suspected of coronary heart disease. We will review the background and current study advances of using coronary artery calcium score, coronary CT angiography, and artificial intelligence in this field.

Microstructure and Mechanical Properties of Mg–2.0Gd–1.2Y–1.0Zn–0.2Zr Alloy

Jianan Liu,Xiaoru Zhang,Wenxue Lv,Yumei Zhou,Daqing Fang,Xiangdong Ding,Jun Sun 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.7

The microstructural evolution of Mg–2.0Gd–1.2Y–1.0Zn–0.2Zr (GWZK) alloy during homogenization and subsequentaging heat-treatment and the tensile properties of the peak-aged sample at various temperatures have been investigated. Thephase transformation during homogenization, static precipitation during aging, and deformation mechanisms at 250 °C aresystematically analyzed through XRD, TEM and EBSD measurements. The peak-aged GWZK alloy has good combinationof strength and ductility at elevated temperatures owing to its high thermal stability by the LPSO phases distributed alongthe grain boundaries. The change (19 MPa) in the yield strength of peak-aged samples between RT and 250 °C is mainlyrelated to easy gliding of dislocations on the non-basal planes due to the decrease in critical resolved shear stress of slip. Two strengthening models are applied to quantitatively describe the efect of {11 −2 0}훼precipitate plates on Orowanstrengthening corresponding to RT and 250 °C. Ignoring changes in solid solution strengthening and grain boundary strengthening of the peak-aged sample caused by increasing temperature, the calculated reduction value (16.5 MPa) in macroscopicyield strength from RT (based on the basal<a>slip mode) to 250 °C (based on the pyramidal<c+a>slip mode) is in goodagreement with the measured reduction value (19 MPa).

Modeling and testing for continuously adjustable damping shock absorber equipped with proportional solenoid valve

Jianan Xu,Farong Kou,Xinqian Zhang,Guohong Wang 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.8

A vehicle's solenoid valve-actuated shock (SVSA) absorber is of wide interest because of its adjustable damping characteristics. The proportional solenoid valve is a pivotal component for commanding damping force, but the research on its model principle still needs to be improved. Therefore, this research aimed to establish an accurate model of the proportional solenoid valve composed of the pilot valve and relief valve. In the pilot valve, we proposed a valve spool structure using a two-stage combined throttling groove to control flow accurately. Then, the dynamic equation of the spool was established, and it is also considered that the magnetic saturation of soft magnetic materials impacts electromagnetic force. The flow force in the dynamic equation was numerically solved by the CFD method. The flow rate in the relief valve was analyzed from the deformation of the lamination valves and main valve plate through the small deflections thin plate theory. Then, the SVSA bench test was carried out. The results show good agreement between the test and calculation, and the maximum error is within 9 %. It is indicated that the model of the SVSA equipped with the proportional solenoid valve has high accuracy.

Skin of the Sea

Wu Jianan 한국콘텐츠학회 2023 ICCC International Digital Design Invitation Exhib Vol.2023 No.12

유전체 봉과 격막 편파기를 이용한 이중 원편파 피드

왕가남(Jianan Wang),홍기표(Ki-Pyo Hong),전동하(Dong-Ha Jun),유상길(Sang-Gil Yu),안병철(Bierng-Chearl Ahn) 한국정보기술학회 2015 한국정보기술학회논문지 Vol.13 No.9

In this paper, a dual-circularly polarized feed is proposed, which operates at 54-64GHz and consists of a square waveguide, a dielectric rod radiator, a septum polarizer and waveguide bends. A stepped taper is applied to the dielectric rod for the required gain and reflection coefficient. Heights and lengths of five steps on a thin metal plate polarizer inserted in the square waveguide are optimized to obtain the desired reflection coefficient at each port, the isolation between ports, and the axial ratio. E-plane bends are connected to the output parts of the septum polarizer for connection with the WR-15 waveguide. Fabrication and measurement show that the proposed feed has a reflection coefficient of less than -10dB and a transmission coefficient of less than -9.5dB at 57-64GHz, and at 60GHz, a maximum gain of 16.8dBic, a 15-dB taper beamwidth of 60°, an axial ratio of less than 2dB within ±30° from the feed axis.

Shear performance of an innovative UHPFRC deck of composite bridge with coarse aggregate

Qi, Jianan,Wanga, Jingquan,Feng, Yu Techno-Press 2019 Advances in concrete construction Vol.7 No.4

This paper presents an experimental study on the structural performance of an innovative ultra-high performance fiber reinforced concrete (UHPFRC) deck with coarse aggregate of composite bridge under shear force. Test parameters included curing method and shear span-to-height ratio. Test results indicated that more short fine cracks developed beside the existing cracks due to the randomly dispersed fibers, resulting in re-distributing and homogenizing of the concrete stress beside cracks and allowing for the occurrence of more cracks with small spacing compared to normal strength concrete beams. Curing methods, incorporating steam curing and natural curing, did not have obvious effect on the nominal bending cracking strength and the ultimate strength of the test specimens. Shear reinforcement need not be provided for UHPFRC decks with a fiber volume fraction of 2%. UHPFRC decks showed superior load resistance ability after the appearance of cracks and excellent post-cracking deformability. Lastly, the current shear provisions were evaluated by the test results.