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您的检索式：作者名="Mahmood Fathi"
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| 1 | Performance of beacon safety message dissemination in Vehicular Ad hoc NETworks (VANETs)显示文摘Currently, there is a growing belief that putting an IEEE 802.11-like radio into road vehicles can help the drivers to travel more safely. Message dissemination protocols are primordial for safety vehicular applications. There are two types of safety messages which may be exchanged between vehicles: alarm and beacon. In this paper we investigate the feasibility of deploying safety applications based on beacon message dissemination through extensive simulation study and pay special attention to the safety requirements. Vehicles are supposed to issue these messages periodically to announce to other vehicles their current situation and use received messages for preventing possible unsafe situations. We evaluate the performance of a single-hop dissemination protocol while taking into account the quality of service (QoS) metrics like delivery rate and delay. We realize that reliability is the main concern in beacon message dissemination. Thus, a new metric named effective range is defined which gives us more accurate facility for evaluating QoS in safety applications specifically. Then, in order to improve the performance, the effects of three parameters including vehicle's transmission range, message transmission's interval time and message payload size are studied. Due to special characteristics of the safety applications, we model the relationship between communication-level QoS and application-level QoS and evaluate them for different classes of safety applications. As a conclusion, the current technology of IEEE 802.11 MAC layer has still some challenges for automatic safety applications but it can provide acceptable QoS to driver assistance safety applications. | YOUSEFI Saleh FATHY Mahmood BENSLIMANE Abderrahim | 2007 | Journal of Zhejiang University-Science A(Applied Physics & Engineering)2007，8，12： | 4 |
| 2 | 关于儿童新型冠状病毒肺炎的系统综述显示文摘该综述的目的是描述儿童新型冠状病毒肺炎(coronavirus disease 2019,COVID-19)的临床特征,重点探讨儿童不易感染COVID-19的可能原因,以及儿童免疫反应是否比成人更好。为此,确定了以下3个研究问题:(1)为什么儿童COVID-19病例临床症状较成人轻?(2)儿童COVID-19患者的临床表现、诊断和治疗如何?(3)痊愈后病毒排毒期持续多久?我们检索了MEDLINE、Embase、Cochrane Central Register of Controlled Trials和Cochrane Database of Abstracts of Reviews of Effects等数据库,以及有英文翻译的国外文献。并从谷歌学术和美国微生物学会收集了其他的信息和数据。从收集的文献中,提取患者的年龄、合并症、治疗方法及对病死率、发病率影响的相关信息。该综述表明,与成人相比,儿童不易患COVID-19,若患上COVID-19,其症状较成人轻。儿童COVID-19发病率较低,病情较成人轻,这可能归因于许多理论和原因,然而所涉及的机制尚不完全清楚。 | Majid Mohammed Mahmood Ilhama Jafarli Aras Fathi Al-Barazanchi Nadhim Mohammed Mosa Zenab Ghanim Younus Al-Ameen Taghreed Alkhanchi | 2021 | 中国当代儿科杂志2021，23，11： | 2 |
| 3 | A Fuzzy Logic Based Sensor Relocation Betterment for Mobile Wireless Sensor Networks显示文摘 | Ehsan Khazaei Mahmood Fathi Mohammad Mehrani | 2012 | 通讯和计算机(中英文版)2012，9，3： | 0 |
| 4 | Planning VANET infrastructures to improve safety awareness in curved roads显示文摘We analyze the effect of using a vehicular ad-hoc network(VANET) on accident avoidance.As shown in our analysis,a higher frequency of safety packets can prevent accidents,even for high speed vehicles and dense roads.To overcome connectivity problems in blind crossing situations,a genetic algorithm(GA) based method is presented for VANET infrastructure planning.The proposed approach tries to remove coverage sight holes in low sight distance cases in a traveling path in the road.In such places,drivers might not have enough sight for proper action and also environmental obstacles prevent direct communication between vehicles.Furthermore,curved roads affect mobility.Simulation results show that the density of vehicles is increased right before a curve and is decreased after that.Therefore,in this kind of road,a high frequency of packet generation may not act well in accident avoidance.The method proposed in this paper tries to cover such places considering the lowest safety distances according to traffic theory.For this,the road must be covered directly by infrastructure.Therefore,the problem is to find the best number and also positions of road side units.Using GA,the algorithm minimizes the summation of total uncovered and overlapped points in the roads which are covered by more than one antenna.Simulation on a real road map confirmed the capabilities of the proposed approach. | Hossein GHAFFARIAN Mohsen SORYANI Mahmood FATHY | 2012 | Journal of Zhejiang University-Science C(Computers and Electronics)2012，13，12： | 0 |
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