检索结果-南通市图书馆

Design and experiment of multi-row pneumatic precision metering device for rapeseed

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2018年第5期11卷 116-123页

作者： elebaid jabir ibrahim Qingxi Liao Lei Wang Yitao Liao Lu Yao College of Engineering Huazhong Agricultural UniversityWuhanHubei 430070China

The main objective of this study was to design a pneumatic disk with four-rows for planting rapeseed and to investigate its performance under several rotating speeds and vacuum pressure *** effects of rotating speeds,vacuum pressure and rows on seed sucking and retaining were *** rotating speeds(5 r/min,10 r/min,15 r/min,20 r/min,25 r/min and 30 r/min)incorporated with the application of vacuum pressure were employed for detecting the optimum vacuum amount that was sufficient for seed sucking under each *** values of vacuum were found to be 1.1 kPa,1.25 kPa,1.35 kPa,1.65 kPa,1.8 kPa and 2.0 kPa,***,a regression model was developed for predicting of vacuum pressure that corresponds with each rotating *** on seed mass analysis,statistical differences were found at 5%significance under the influence of speeds and negative pressure and existed also between and within rows according to Duncan’s *** highest seed mass means of 3.17 g and 3.96 g were obtained by row 1 under the effects of speed and vacuum pressure,respectively,while the lowest means of 2.79 g and 3.05 g were attained by row *** to the influence of rows,important differences were occurred between row 1(closer to the center of rotation)and row 4(farther one),particularly under high speeds(25 r/min and 30 r/min).Results concluded that,pneumatic disk with multiple-rows could be satisfactorily used for seed sowing with a little variation in seed amount between rows without any seed *** rows of hole farther from plate center of rotation were obviously influenced by angular velocity and vacuum amount rather than the closer ones.

关键词： precision seeder metering device performance pneumatic disk multi-rows rapeseed

Is political business cycle an enemy to human development?Empirical evidence from Africa

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Economic and Political Studies 2019年第3期7卷 337-351页

作者： Abdul Ganiyu Iddrisu jabir ibrahim Mohammed Department of Economics University of GhanaLegonGhana Business School University of GhanaLegonGhana

Extant literature has argued that,with major extension of democracy since the 1990s,political business cycle has become more intense and has made African political systems more *** light of this,this paper examines both the existence of African political business cycles and their impact on human *** confirms the existence of political business cycles in *** of a panel fixed effects and system-GMM regression techniques for 38 African countries from 1990 to 2015 also suggest that such cycles worsen human development in African *** finding is consistent if we limit our analysis to various sub-regions of Africa,and also at two different income levels.

关键词： Political business cycle human development Africa

Enhancing Network Design through Statistical Evaluation of MANET Routing Protocols

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第7期80卷 319-339页

作者： ibrahim Alameri Tawfik Al-Hadhrami Anjum Nazir Abdulsamad Ebrahim Yahya Atef Gharbi Faculty of Medical Sciences Jabir ibn Hayyan Medical UniversityAlkufa QuNajaf54001Iraq Computer Science Department School of Science and TechnologyNottingham Trent UniversityNottinghamNG118NSUK Department of Computing Faculty of Engineering Sciences&Technology(FEST)Hamdard UniversityKarachi74600Pakistan Department of Information Technology College of Computing and Information TechnologyNorthern Border UniversityArar91431Saudi Arabia Department of Information System College of Computing and Information TechnologyNorthern Border UniversityArar91431Saudi Arabia

This paper contributes a sophisticated statistical method for the assessment of performance in routing protocols salient Mobile Ad Hoc Network(MANET)routing protocols:Destination Sequenced Distance Vector(DSDV),Ad hoc On-Demand Distance Vector(AODV),Dynamic Source Routing(DSR),and Zone Routing Protocol(ZRP).In this paper,the evaluation will be carried out using complete sets of statistical tests such as Kruskal-Wallis,Mann-Whitney,and *** articulates a systematic evaluation of how the performance of the previous protocols varies with the number of nodes and the mobility *** study is premised upon the Quality of Service(QoS)metrics of throughput,packet delivery ratio,and end-to-end delay to gain an adequate understanding of the operational efficiency of each protocol under different network *** findings explained significant differences in the performance of different routing protocols;as a result,decisions for the selection and optimization of routing protocols can be taken effectively according to different network *** paper is a step forward in the general understanding of the routing dynamics of MANETs and contributes significantly to the strategic deployment of robust and efficient network infrastructures.

关键词： Routing protocols statistical approach friedman MANET

Optimizing Connections:Applied Shortest Path Algorithms for MANETs

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第10期141卷 787-807页

作者： ibrahim Alameri Jitka Komarkova Tawfik Al-Hadhrami Abdulsamad Ebrahim Yahya Atef Gharbi Faculty of Medical Sciences Jabir Ibn Hayyan Medical UniversityAlkufaNajaf54001Iraq Faculty of Economics and Administration University of PardubiceStudentskaPardubice53210Czech Republic Computer Science Department School of Science and TechnologyNottingham Trent UniversityNottinghamNG118NSUK Department of Information Technology College of Computing and Information TechnologyNorthern Border UniversityArar91431Saudi Arabia Department of Information System College of Computing and Information TechnologyNorthern Border UniversityArar91431Saudi Arabia

This study is trying to address the critical need for efficient routing in Mobile Ad Hoc Networks(MANETs)from dynamic topologies that pose great challenges because of the mobility of *** objective was to delve into and refine the application of the Dijkstra’s algorithm in this context,a method conventionally esteemed for its efficiency in static ***,this paper has carried out a comparative theoretical analysis with the Bellman-Ford algorithm,considering adaptation to the dynamic network conditions that are typical for *** paper has shown through detailed algorithmic analysis that Dijkstra’s algorithm,when adapted for dynamic updates,yields a very workable solution to the problem of real-time routing in *** results indicate that with these changes,Dijkstra’s algorithm performs much better computationally and 30%better in routing optimization than Bellman-Ford when working with configurations of sparse *** theoretical framework adapted,with the adaptation of the Dijkstra’s algorithm for dynamically changing network topologies,is novel in this work and quite different from any traditional *** adaptation should offer more efficient routing and less computational overhead,most apt in the limited resource environment of ***,from these findings,one may derive a conclusion that the proposed version of Dijkstra’s algorithm is the best and most feasible choice of the routing protocol for MANETs given all pertinent key performance and resource consumption indicators and further that the proposed method offers a marked improvement over traditional *** paper,therefore,operationalizes the theoretical model into practical scenarios and also further research with empirical simulations to understand more about its operational effectiveness.

关键词： Dijkstra’s algorithm optimization complexity analysis shortest path first comparative algorithm analysis nondeterministic polynomial(NP)-complete

Prevalence and Associated Factors of Back Pain among Medical Students in Sudan

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Health 2022年第9期14卷 931-938页

作者： Shahda Shms Eldeen Khlf Alla Ahmed Ragda Kabashy Mohammed Bahar Lana Alsiddig Mohamed Ahmed Aisha Ali Elameen Abbas Eiman Siddig Abd Elhadi Ahmed Ruba jabir Abdallah Seedahmed Shahd Yousif Hajomer Abdelgader Arwa Ahmed Alhussain Ahmed Khalid Elfadil ibrahim Husein Faculty of Medicine Omdurman Islamic University Omdurman Sudan Department of Orthopaedics and Traumatology Omdurman Islamic University Omdurman Sudan

Background: Back pain affects old and young adults, and it is a common complain among medical students. Objective: To estimate the prevalence of back pain and associated factors among medical students in Sudan. Method: An observational multi-universal cross-sectional study was conducted from December 2021 to February 2022, involving 433 medical students selected by simple random sampling. Data were collected by electronic Google Form questionnaire designed to assess demographic features, back pain characteristics, and triggering factors. Data analysis was done by statistical package for social sciences. Result: The prevalence of back pain among medical students in Sudan is 69.3%, with a statistically insignificant difference between preclinical and clinical students (p value: 0.378), and between male and female students (p value: 0.826). The lower back is the commonest site of pain (75%). The majority of the students experience moderate pain (53.9%). They did not use medications (81%). Sitting for long hours is the most common trigger (87.9%) and the pain did not interfere with the daily activities (71%). Conclusion: Back pain is a common complain among medical students in Sudan. Medical schools should raise the awareness of the students about back pain.

关键词： Back Pain Medical Students Medical School Sudan

Prevalence and Associated Factors of Back Pain among Medical Students in Sudan

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论