http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Bo Cheng,Xuefeng Guan 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.12
Web Map Tile Services (WMTS) have been widely used for quick and convenient sharing of geospatial information. In practice, when streaming requests to servers increase in scale, unacceptable response times and service unavailability might result. To address this scalability problem, we implemented a scalable WMTS framework on a high performance cluster (HPC), enabling the realization of elastic deployment as the client users grow in number. This scalable and high-concurrency WMTS is built totally with open-source software, including Nginx, GeoWebCache, and MongoDB. In this architecture, Nginx acts as a powerful load balancer for routing client requests; GeoWebCache is customized to publish the required WMTS and process client requests; while MongoDB is used to store the large volume of tile images in the HPC. Evaluation experiments were carried out to assess the efficiency and scalability of our WMTS system, using one synthetic workload. Experimental results illustrate that this distributed WMTS framework can achieve about 15% performance improvement when the service nodes are increased with a 0.5~2s reduction in the load time and a 5~10MB increase in network throughput.
Study on Tribological Properties of Laser-Textured Plunger in Methanol Engine
Bifeng Yin,Yuhao Jiang,Bo Xu,Hekun Jia,Xuefeng Wang 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.4
Considering the eccentricity and deformation of the plunger, a lubrication model of laser-textured plunger pair was established to research friction-and-wear performance of typical surface texture on the plunger under diesel and methanol lubrication. The calculation results show that for the non-textured plunger, the oil film thickness and fluid friction under methanol lubrication are lower than diesel lubrication, and the asperity friction was greater than diesel lubrication, indicating that methanol may deteriorate the lubrication performance of the plunger surface. After texturing the plunger, the oil film thickness and fluid friction during methanol lubrication are greater than the non-textured scheme, and the asperity friction is lower than the non-textured scheme, which means that the surface texture has the potential to improve the lubrication performance of the plunger. The friction and wear tests results indicate that the average friction coefficient of the textured plunger is reduced by 3.4 ~ 6.2 % compared with the non-textured plunger in methanol lubrication. The lubrication performance of the textured plunger during methanol lubrication reaches the level of the non-textured plunger in diesel lubrication. After the wear test, the surface wear depth of the textured plunger is reduced by 16.2 % compared with the non-textured plunger in methanol lubrication condition.
Effects of Momordica charantia Saponins on In vitro Ruminal Fermentation and Microbial Population
Kang, Jinhe,Zeng, Bo,Tang, Shaoxun,Wang, Min,Han, Xuefeng,Zhou, Chuanshe,Yan, Qiongxian,He, Zhixiong,Liu, Jinfu,Tan, Zhiliang Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.4
This study was conducted to investigate the effects of Momordica charantia saponin (MCS) on ruminal fermentation of maize stover and abundance of selected microbial populations in vitro. Five levels of MCS supplements (0, 0.01, 0.06, 0.30, 0.60 mg/mL) were tested. The pH, $NH_3-N$, and volatile fatty acid were measured at 6, 24, 48 h of in vitro mixed incubation fluids, whilst the selected microbial populations were determined at 6 and 24 h. The high dose of MCS increased the initial fractional rate of degradation at t-value = 0 ($FRD_0$) and the fractional rate of gas production (k), but decreased the theoretical maximum of gas production ($V_F$) and the half-life ($t_{0.5}$) compared with the control. The $NH_3-N$ concentration reached the lowest concentration with 0.01 mg MCS/mL at 6 h. The MSC inclusion increased (p<0.001) the molar proportion of butyrate, isovalerate at 24 h and 48 h, and the molar proportion of acetate at 24 h, but then decreased (p<0.05) them at 48 h. The molar proportion of valerate was increased (p<0.05) at 24 h. The acetate to propionate ratio (A/P; linear, p<0.01) was increased at 24 h, but reached the least value at the level of 0.30 mg/mL MCS. The MCS inclusion decreased (p<0.05) the molar proportion of propionate at 24 h and then increased it at 48 h. The concentration of total volatile fatty acid was decreased (p<0.001) at 24 h, but reached the greatest concentration at the level of 0.01 mg/mL and the least concentration at the level of 0.60 mg/mL. The relative abundance of Ruminococcus albus was increased at 6 h and 24 h, and the relative abundance of Fibrobacter succinogenes was the lowest (p<0.05) at 0.60 mg/mL at 6 h and 24 h. The relative abundance of Butyrivibrio fibrisolvens and fungus reached the greatest value (p<0.05) at low doses of MCS inclusion and the least value (p<0.05) at 0.60 mg/mL at 24 h. The present results demonstrates that a high level of MCS quickly inhibits in vitro fermentation of maize stover, while MCS at low doses has the ability to modulate the ruminal fermentation pattern by regulating the number of functional rumen microbes including cellulolytic bacteria and fungi populations, and may have potential as a feed additive applied in the diets of ruminants.
Zelin Nie,Wei Cheng,Guanghui Zhou,Xuefeng Chen,Chao-Bo Yan,Feng Gao 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.6
Under the unique environment of high humidity and high salinity of nuclear power plants, the environment should be improved to ensure staff comfort and equipment safe operation. Meanwhile, because of energy shortage, it is of great significance for building to save energy and reduce consumption. This paper first introduces the concept of Majorization to ensure user comfort with control smoothness, improving the existing two-timescale heating, ventilation, and air conditioning (HVAC) optimization model. Then, considering energy consumption, this paper formulates a multi-objective programming (MOP) problem with the objective to seek a balance between user comfort and energy consumption. The MOP model is solved by constructing the trade-off curve, where a subobjective with Majorization is also a MOP problem nested, which can be solved more simply using the characteristic of two-timescale HVAC optimization. The numerical results demonstrate the Pareto optimal solutions and the better energy-saving effect compared with the existing two-timescale model.
Quantitative Reduction of Basilar Invagination With Atlantoaxial Dislocation by a Posterior Approach
Jian Guan,Fengzeng Jian,Qingyu Yao,Chenghua Yuan,Can Zhang,Longbing Ma,Zhenlei Liu,Wanru Duan,Xingwen Wang,Xuefeng Bo,Zan Chen 대한척추신경외과학회 2020 Neurospine Vol.17 No.3
Objective: This study evaluated the feasibility and efficacy of quantitative reduction and fixation to treat basilar invagination (BI) with atlantoaxial dislocation (AAD). Methods: Posterior occipitocervical angle (POCA), occiput–C2 angle (Oc–C2A), clivusaxial angle (CAA), and C2–7 angle (C2–7A) were considered for quantitative reduction. Twelve patients with BI complicated with AAD received posterior interarticular release and individualized cage implantation to restore vertical dislocation. The POCA was adjusted using cantilever technology to further reduce the horizontal dislocation and adjust lower cervical vertebral angle. All patients received a radiological follow-up for ≥12 months. Improvements in spinal cord function were evaluated using Japanese Orthopedic Association (JOA) score. Results: All the patients received successful quantitative reduction for BI-AAD, and bony fusion was achieved without spinal cord injury after surgery for 12 months. The JOA score was improved significantly to 15.2 ± 0.9 twelve months after surgery (p < 0.01). Radiological follow-up revealed that individualized cage and POCA play vital roles in quantitative correction: (1) distance of the dens above McRae’s line and atlantodens interval were restored to normal level, respectively; (2) changes in Oc–C2 angle (ΔOc–C2A), C2–7 angle (ΔC2–7A), clivus-axial angle (ΔCAA), and POCA (ΔPOCA) were all caused by changes in axis tilt. Based on the changes of radiological parameter we deduced the formula for quantitative reduction by linear regression analysis: -ΔPOCA = ΔOc–C2A = -ΔC2–7A = ΔCAA. Conclusion: Quantitative posterior reduction by individualized cage and adjusting ΔPOCA is feasible for treating BI with AAD.