Measurement and Prediction of Indoor air flow in a Large Space

Zongyi Shao,Yanli Ren,Deying Li 국제온돌학회 2007 International Journal of Ondol Vol.2 No.1

Correct air diffusion is essential for good air quality, comfortable conditions and energy efficiency in mechanical ventilation system. One general method to improve indoor air quality is to simply increase the ventilation rate. This approach, however, often conflicts with building energy efficiency requirement because conditioning outdoor air to the proper temperature, humidity level count for use as ventilation air consumes energy. Therefore, it is necessary for designers to predict the air movement properly. Successful predictions of room airflow yield such information as velocities and temperature distributions, which are useful to building design and analysis. In this paper, the application of computational fluid dynamic (CFD) techniques to large space design and analysis was investigated by comparing the results of CFD simulations and experimental results.

Multiple-Phase Energy Detection and Effective Capacity Based Resource Allocation Against Primary User Emulation Attacks in Cognitive Radio Networks

( Zongyi Liu ),( Guomei Zhang ),( Wei Meng ),( Xiaohui Ma ),( Guobing Li ) 한국인터넷정보학회 2020 KSII Transactions on Internet and Information Syst Vol.14 No.3

Cognitive radio (CR) is regarded as an effective approach to avoid the inefficient use of spectrum. However, CRNs have more special security problems compared with the traditional wireless communication systems due to its open and dynamic characteristics. Primary user emulation attack (PUEA) is a common method which can hinder secondary users (SUs) from accessing the spectrum by transmitting signals who has the similar characteristics of the primary users’ (PUs) signals, and then the SUs’ quality of service (QoS) cannot be guaranteed. To handle this issue, we first design a multiple-phase energy detection scheme based on the cooperation of multiple SUs to detect the PUEA more precisely. Second, a joint SUs scheduling and power allocation scheme is proposed to maximize the weighted effective capacity of multiple SUs with a constraint of the average interference to the PU. The simulation results show that the proposed method can effectively improve the effective capacity of the secondary users compared with the traditional overlay scheme which cannot be aware of the existence of PUEA. Also the good delay QoS guarantee for the secondary users is provided.

Dynamic performance reliability analysis of rolling linear guide under parameter uncertainty

Jian Li,Yan Ran,Hongwei Wang,Guangquan Huang,Zongyi Mu,Genbao Zhang 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.11

This paper presents a dynamic reliability analysis method of rolling linear guide considering the uncertainty of geometric parameters. A three degree of freedom (DOF) dynamic motion model of rolling linear guide that considers the complexity of the actual load is established. In order to improve the accuracy of reliability evaluation, interval model is used to express the uncertainty of geometric parameters. The reliability range of dynamic response is determined according to the accuracy grade of rolling linear guide. The interval reliability calculation method is used to analyze and calculate the horizontal and vertical dynamic reliability of rolling linear guide. Then, the comprehensive dynamic reliability of rolling linear guide is obtained. Finally, the dynamic reliability of the SHS-45R rolling linear guide is analyzed by using the reliability evaluation method described in this paper. And the validity and accuracy of the result is demonstrated by comparing with the Monte Carlo simulation.

The Effect of Soybean Galactooligosaccharides on Nutrient and Energy Digestibility and Digesta Transit Time in Weanling Piglets

Zhang, Liying,Li, Defa,Qiao, Shiyan,Wang, Jituan,Bai, Lu,Wang, Zongyi,Han, In K. Asian Australasian Association of Animal Productio 2001 Animal Bioscience Vol.14 No.11

Eight $12.4{\pm}0.6kg$ initial body weight crossbred barrows were used to determine the effect of soybean galactooligosaccharides on nutrient and energy digestibility, and digesta transit time. Four dietary treatments were utilized in this trial. Treatment one was a corn-soybean meal based diet (SBM) containing raffinose and stachyose at the levels of 0.16% and 0.75%, respectively. Treatment two (control) was a corn-HP300 (soybean concentrate protein) diet. In treatments three and four, 1.1% and 2.2% commercial stachyose was added to the control diet to provide total dietary stachyose at the levels of 1% and 2%, respectively. The soybean galactooligosaccharides (raffinose + stachyose) level in treatment one was slightly lower compared to that in treatment three. Three collection periods were run with two pigs for each treatment/period. There was a 4 d adjustment period followed by a 3 d collection period. The results showed that the nitrogen retention (86.79%) of pigs fed treatment two diet was higher than that of pigs fed treatment one by 5.2% (p<0.05). The nitrogen retention of treatment three was intermediate 83.09%. The apparent fecal digestibility of all amino acids in treatment two was numerically highest, followed by treatments three and four. However, there were no significant difference among groups (p>0.05). The dry matter (DM), organic matter (OM), crude protein (CP), and crude fiber (CF) digestibility numerically decreased as the soybean galactooligosaccharides level increased, but were not significantly different (p>0.05). Chromium content in feces (from the inclusion of 0.3% chromic oxide in the diets) differed among treatments (p<0.05) at 15 h, 18 h, and 21 h after eating. This showed that the digesta transit time was differed significantly among treatments. Treatment four was the shortest, followed by treatment three, SBM and control. The results demonstrated that in the absence of antinutritional factors and soybean antigen protein, inclusion of 1% and 2% stachyose in corn-HP300 diet has no significant effect on the digestibility of DM, OM, CP, CF and amino acids. When the soybean galactooligosaccharide level in diet one and diet three were adjusted to be almost the same, antinutritional factors such as trypsin inhibitor and soybean antigen protein could decrease the nutrient digestibility and nitrogen retention rate of diet. High levels of soybean galactooligosaccharides shortened the digesta transit time in the intestinal tract. This trial suggested that the total level of soybean galactooligosaccharides (stachyose+raffinose) in the weanling piglet diet is better not to exceed 1% when common soybean meal is used as main protein source.

Fourier Neural Operator (FNO) 기법을 통한 MJO 예측

강대현,김대현,함유근,Zongyi Li,Kamyar Azizzadenesheli 한국기상학회 2022 한국기상학회 학술대회 논문집 Vol.2022 No.4

Tuning the physicochemical properties of axitinib by crystallization: Preparation, calculation and Structure-property relationship

Haibin Qu,Zhonghua Li,Guimin Zhang,Zongyi Zhou,Songgu Wu 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.124 No.-

Crystal engineering is a radical method to modulate the physicochemical properties of the drugs to meetthe needs of the pharmaceutical industry. Examined herein are six axitinib solid-state forms, includinganhydrous forms (Ⅳand XLI), solvates (acetic acid, nitromethane and n-propanol), and cocrystal (nicotinamide). Comprehensive characterization containing morphology, hygroscopicity, solubility, fluorescenceand powder tabletability were performed. Calculations of lattice energy, packing coefficient andenergy framework rationalized the structure–property relationship of these six forms from the packinglandscape. This system illustrates that form IV and cocrystal improve the solubility of axitinib, but thehumidity stability is also decreased. Six crystal forms show polychromatic solid-state luminescence rangingfrom violet to indigo to green. Form IV and cocrystal with slip plane structures exhibited superior tensilestrength and compactibility than isotropic form XLI. Elusive form VI can be obtained by controllingthe humidity levels during desolvation of the solvate. This work not only realizes the regulation of betterphysicochemical properties of axtinnib for industrial manufacturing, but also provides a detailed understandingof the structure–property relationship of drugs in complex polymorphic systems.