Wind pressure provisions for gable roofs of intermediate roof slope

Stathopoulos, Theodore,Wang, Kai,Wu, Hanqing Techno-Press 2001 Wind and Structures, An International Journal (WAS Vol.4 No.2

The paper addresses the suitability of wind pressure coefficients specified in contemporary design standards and codes of practice for gable roofs of intermediate slope (roof angle $10^{\circ}-30^{\circ}$). In a recent research study, a series of low building models with different roof slopes in this intermediate range were tested in a boundary layer wind tunnel under simulated open country terrain conditions. This was different from the original study in the 70's, which produced the current provisions on the basis of a model tested only for a single roof slope (4:12) in this range. The results of the study suggest that a modification to the American wind provisions would be warranted to make them more representative of the true local and area-averaged wind loads imposed on gable roofs of intermediate slope.

The game of safety behaviors among different departments of the nuclear power plants

Da Yuan,Hanqing Wang,Jian Wu 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.3

To study the developments and variations of unsafe behaviors in nuclear power plants thus reduce thepossibility of human-related accidents, this paper, based on the Game Theory, focused on the changes inbenefits of the Department of Management, Operational and Emergency in a nuclear power plant, andestablished the expected revenue functions of these departments. Additionally, the preventive measuresof unsafe behaviors in nuclear power plants were also presented in terms of these 3 departments. Resultsshowed that the violations of the Operation Department (OD) and the Emergency Department (ED) werenot only relevant with the factors such as their own risks, costs, and the responsibility-sharing due toaccidents, but also affected by the safety investments from the Management Department (MD). Furthermore, results also showed that the accident-induced responsibility-sharing of both the OD andthe ED would rise, if the MD increased the investments in safety. As a result, the probability of violationbehaviors of these 3 departments would be attenuated consciously, which would reduce the unsafebehaviors in the nuclear power plants significantly

Modeling and Emulation of 3d Dither Stability in Orthogonal Turn-Milling

Yueqi Guan,Hanqing Guan,Gaoshen Wang,Rongling Chen 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.6

Aiming at 4-axial orthogonal turn-milling by end mill, its theoretical 3d model for stable range of dither was put forward on the basis of its cutting principle by using analytical method. Based on modal trial, the stable range leaf figure of end mill’s dither in 4-axial turn-milling with eccentricity was simulated and analyzed. The results show that besides geometrical shape of mill, material of workpiece and frequency response function of machine-tool’s structure etc that can produce dither in 4-axial turn-milling, the rotating speed of mill and cutting depth are also related to dither. In trial of 4-axial turn-milling by end mill, the results of cutting force spectrum analysis show that: cutting is stable and un-dither when frequency of cutter tooth cutting-in plays leading role in force spectrum. Dither is produced when modal frequency of system plays leading role in force spectrum, the measured value of cutting force and surface roughness are also higher than those in the condition of un-dither. Thus the theoretical model and results of emulation can predict stability of end mill’s dither in 4-axial orthogonal turn-milling with eccentricity correctly and can provide theoretical guidance for surface quality and processing efficiency of workpiece.

Separating paint mist from paint spraying waste gas: mechanism, model and application

Yihui Zhou,Xi He,Wang Li,Tao Xu,Dong Xie,Xin Dai,Zhang Liu,Hanqing Wang,Gang Yu 대한환경공학회 2021 Environmental Engineering Research Vol.26 No.5

The paint spraying waste gas contains a large amount of paint mist, volatile organic compounds (VOCs) and other hazardous materials, which seriously affects human health and atmospheric environment. Paint mist cannot be separated from paint spraying waste gas effectively by the existing dry filtration methods because of the filter blocking. A new separation process and a novel coupling device with high separation efficiency have been developed. A numerical model was established to optimize the structure and operation parameters of the baffle interceptor by hydrodynamics method which verified by the coupling device experiment. From the simulating results, when plate spacing was 20 ㎜, folding angle was 90° and airflow velocity was up to 8 ㎧, the separation efficiency of paint mist with the diameter of 15 ㎛ was 84.7% and the pressure drop of the baffle interceptor was 220.2 ㎩. Experiment was conducted under the above-optimized conditions, and the results showed that the pressure drop of the baffle interceptor was 303.33 ㎩, and the paint mist separation efficiencies of the baffle interceptor and the interception-filtration coupling device were 78.34% and 96.38%, respectively.

A Hierarchical Approach for Background Modeling and Moving Objects Detection

Jie Yang,Jinqiao Wang,Hanqing Lu 제어·로봇·시스템학회 2010 International Journal of Control, Automation, and Vol.8 No.5

In this paper, we propose a hierarchical approach for background modeling and moving objects detections in the intelligent visual surveillance system. The proposed approach models the background in block level and pixel level hierarchically, and the background is represented by texture information in block level and by color information in pixel level respectively. Meanwhile the variable parameters learning rate is proposed to speed up the convergence of the model parameters in the pixel model. The proposed approach provides us with many advantages compared to the state-of-the-art. Experimental results demonstrate the effectiveness and efficiency of the proposed approach.

Investigating the Influences of Wet Fiber Laser Cutting Upon the Surface Integrity of Nitinol Cardiovascular Stents

Xiaoyu Sun,Xiuting Wei,Zhiyong Li,Deda Lou,Yongqi Wang,Hanqing Liu 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.7

High precision laser cutting with minimal post-treatment is needed in the manufacturing of nitinol cardiovascular stents. This paper carries out a series of cutting experiments of nitinol cardiovascular stents by wet fiber laser cutting to understand the basic process characteristics and to investigate the influences of process parameters (laser power, cutting speed, pulse width, frequency) upon the surface integrity (surface topography, dross, surface roughness, HAZ, recast layer, subsurface nanohardness, surface chemical composition). The univariate analysis was used to analyze and explain the influence that rules of process parameters had upon the surface integrity. The experiment results showed that the effects of process parameters on surface integrity were regular, with the optimal single-factor parameters obtained. Moreover, the removal mechanism of the nitinol material was also revealed. This study is of great significance for the medical industry in improve the cutting quality of cardiovascular stents.

Intercropping garlic at different planting times and densities for insect pest or crop yield and value management in tobacco fields

Rongquan LAI,Chaozhi ZHU,Jingjing BAI,Xiaoting WU,Gang GU,Jianbao BAI,Ting ZHOU,Dingfeng WANG,Hanqing HU,Tianran LIN 한국곤충학회 2020 Entomological Research Vol.50 No.3

Although the densities of tobacco pests have been decreased in garlic-tobacco fields, further studies are needed to judge the effects of garlic transplanting densities or times on tobacco pests in tobacco fields. Therefore, field experiments were conducted in Liancheng County in Longyan City, Fujian Province, in China in 2014 and 2015. Myzus persicae (Sulzer) abundance, the species or abundance ratios of enemies and pests, the intercropping effects and the tobacco yield and crop value showed that the effects of transplanting tobacco 10 days after garlic transplantation at a density of 5.85 individual plants per square meter on pests were stronger than those of other treatments. Aphid abundance was significantly lower in transplanting tobacco 10 days after garlic transplantation at a density of 5.85 individual plants per square meter than in the other treatments. The ratio between enemies and pests in transplanting tobacco 10 days after garlic transplantation at a density of 5.85 individual plants per square meter was higher than those in the other treatments. The intercropping effects of transplanting tobacco 10 days after garlic transplantation at a density of 5.85 individual plants per square meter on Myzus persicae, Spodoptera litura (Fabricius), Heliothis assulta Guenee and Nezara viridula Linnaeus were significantly stronger than those of the other treatments, whereas the effects of transplanting tobacco 15 days after garlic transplantation at a garlic density of 5.85 individual plants per square meter on Agrotis ypsilon (Rottemberg) were significantly stronger. Additionally, the yield and crop value of transplanting tobacco 10 days after garlic was transplanted at a density of 5.85 individual plants m ̅2 were higher than those of the other treatments. Therefore, our study demonstrated that the model of transplanting tobacco 10 days after garlic was transplanted at a density of 5.85 individual plants m ̅2 is an optimal management strategy to control flue-cured tobacco pests and to acquire higher crop yield in garlic-tobacco fields.