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Zeeshan Kaleem,KyungHi Chang 한국통신학회 2012 한국통신학회 학술대회논문집 Vol.2012 No.6
The cloud radio access network (C-RAN) architecture has made possible to use the concept of clusters by combining hundred’ s of base stations by using remote radio heads (RRH), and thus enable us to use the properties of base station cooperative transmission technique, i.e., CoMP. In this paper, we proposed a procedure related to DL/UL CoMP which has fully exploited the cloud architecture and CoMP techniques to mitigate the inter cell interference (ICI), and proposed the method of selecting the proper CoMP technique which not only maximizes the throughput performance for the cell edge users but also keeps in front the throughput of other users in the cooperating set.
Zeeshan Nawaz,Tang Xiaoping,Fei Wei 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.6
The direct catalytic dehydrogenation of propane to propene is an important route to enhance propene production. In the present experimentation the focus was to investigate the influence of incipient operating conditions, Si/Al ratio of zeolite support and effect of zinc doping on Pt-Sn/ZSM-5 catalyst performance. The catalysts were extensively investigated by reaction tests in a continuous plug-flow quartz micro-reactor. The experimental data shows that the manipulation of operating parameters significantly improves the reaction performance, while huge dynamicity is observed in product distribution. Reaction temperature, 600℃ is found to be most suitable, while increasing the weight hourly space velocity (WHSV), propene selectivity improves at the expense of lower conversion. The OPE was drawn to observe overall reaction network. It was found that the acidity of zeolitic support plays a more important role in achieving desired product selectivity than additional metallic content. Accordingly, the Si/Al ratio of the ZSM-5 zeolite the pro- pene selectivity was enhanced, leading to remarkable improvement in the total olefins selectivity which was remarkably improved owing to a suppression of secondary reactions. At Si/Al ratio 300, the selectivity of propene and total olefins becomes stable at 73% and 90% respectively. The doping of Zn on Pt-Sn/ZSM-5 improves only propene selectivity, but is severely affected by quick deactivation.
Performance Analysis of Path Planning Algorithms for Fruit Harvesting Robot
Zeeshan Sadaf,Aized Tauseef 한국농업기계학회 2023 바이오시스템공학 Vol.48 No.2
Purpose Path planning is an essential part in designing of an agricultural robot. The path planning algorithms for fruit harvesting robots vary in performance, based on diff erent environments, obstacles, and constraints. This research aims to analyze and evaluate the most commonly used path planning algorithms by fruit harvesting robots in the past 10 years to assess the robot’s performance. The primary objective behind the comparative analysis of path planning algorithms is to ascertain which algorithm demonstrates better performance in terms of reaching the target fruit in the shortest time, requiring the least amount of computing resources, and being able to navigate around obstacles eff ectively. Hence, the study determines which path planning algorithm is the most effi cient for the application of fruit harvesting robot. Method In this study, four common path planning algorithms were evaluated namely A-star, Probabilistic Road Map, Rapidly exploring Random Tree, and improved Rapidly exploring Random Tree. Three cases were examined for performance. The fi rst case deals with performance based on varying orientations of fruit within the workspace. The second case investigates the performance in the presence of obstacles in the path, and the third case caters to performance due to varying distances of robot and the fruit. Matlab software was used for creating simulation environment for testing. Run time, path length, standard deviation, and total task time were obtained for each case and statistical analysis was done. Results It was found that improved Rapidly exploring Random Tree performed better in terms of path length and gave an optimal path as compared to the other algorithms due to its rewiring feature by an average of 21%. Run time of Rapidly exploring Random Tree was better than the other three algorithms. Conclusion Four most commonly used path planning algorithm were analyzed for performance for fruit harvesting robot for three diff erent cases. Despite the variations in performance across diff erent scenarios, the results confi rmed that the improved Rapidly exploring Random Tree algorithm outperformed all other algorithms under the given constraints.
Zeeshan Nawaz,Tang Xiaoping,Xiaobo Wei,Fei Wei 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.5
To process the solid particulates in fluidized bed and slurry phase reactors, attrition is an inevitable consequence and is therefore one of the preliminary parameters for the catalyst design. In this paper, the mechanical degradation propensity of the zeolite catalysts (particles) was investigated in a bimodal distribution environment using a Gas Jet Attrition - ASTM standard fluidized bed test (D-5757). The experimentation was conducted in order to explore parameters affecting attrition phenomena in a bimodal fluidization. In a bimodal fluidization system, two different types of particles are co-fluidized isothermally. The air jet attrition index (AJI) showed distinct increases in the attrition rate of small particles in a bimodal fluidization environment under standard operating conditions, in comparison with single particle. A series of experiments were conducted using particles of various sizes, with large particles of different densities and sizes. Experimental results suggest that the relative density and particle size ratio have a significant influence on attrition behavior during co-fluidization. Therefore a generalized relationship has been drawn using Gwyn constants;those defined material properties of small particles. Moreover, distinct attrition incremental phenomenon was observed during co-fluidization owing to the change in collision pattern and impact, which was associated with relative particle density and size ratios.