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Examining the Use of Scott’s Formula and Link Expiration Time Metric for Vehicular Clustering

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Computer Modeling in Engineering & Sciences 2024年第3期138卷 2421-2444页

作者： fady Samann Shavan Askar Department of Energy Engineering Technical College of EngineeringDuhok Polytechnic UniversityDuhok42001Iraq Department of Information System Engineering Technical College of EngineeringErbil Polytechnic UniversityErbil44001Iraq

Implementing machine learning algorithms in the non-conducive environment of the vehicular network requires some adaptations due to the high computational complexity of these algorithms.K-clustering algorithms are simplistic,with fast performance and relative ***,their implementation depends on the initial selection of clusters number(K),the initial clusters’centers,and the clustering *** paper investigated using Scott’s histogram formula to estimate the K number and the Link Expiration Time(LET)as a clustering *** traffic flows were considered for three maps,namely Highway,Traffic Light junction,and Roundabout junction,to study the effect of road layout on estimating the K number.A fast version of the PAM algorithm was used for clustering with a modification to reduce time *** Affinity propagation algorithm sets the baseline for the estimated K number,and the Medoid Silhouette method is used to quantify the ***++,Veins,and SUMO were used to simulate the traffic,while the related algorithms were implemented in *** Scott’s formula estimation of the K number only matched the baseline when the road layout was ***,the clustering algorithm required one iteration on average to converge when used with LET.

关键词： Clustering vehicular network Scott’s formula FastPAM

Flag-Based Vehicular Clustering Scheme for Vehicular Ad-Hoc Networks

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Computers, Materials & Continua 2023年第12期77卷 2715-2734页

Clustering schemes in vehicular networks organize vehicles into logical *** are vital for improving network performance,accessing the medium,and enabling efficient data *** schemes rely on periodically broadcast hello messages to provide up-to-date information about the ***,the periodic exchange of messages overwhelms the system and reduces *** paper proposes the Flag-based Vehicular Clustering(FVC)*** scheme leverages a combination of Fitness Score(FS),Link Expiration Time(LET),and clustering status flags to enable efficient cluster formation in a hybrid *** FVC relies on the periodic broadcast of the basic safety message in the Dedicated Short-Range Communications(DSRC)standard for exchanging the vehicle’s status,FS,and joining *** extra information onto the existing periodic beacon reduces the overhead of exchanging additional control messages,which is the main contribution of this *** scheme is implemented in a hybrid manner by utilizing a Road Side Unit(RSU)to implement a clustering *** work considered the FastPAM algorithm,a fast version of the Partitioning Around Medoids(PAM)clustering algorithm,to generate a list of potential cluster *** FVC scheme uses the LET as the clustering metric with the FastPAM ***,the Lightweight FastPAM Vehicular Clustering(LFPVC)algorithm is considered by selecting the initial cluster heads based on the FS instead of the greedy FastPAM’s build *** the absence of the RSU,the vehicles utilize the FS with proper back-off time to self-elect the cluster *** hybrid FVC scheme increased the cluster lifetime by 32%and reduced the control-message overhead by 63%compared to the related ***,the LFPVC algorithm achieved similar results to the FastPAM algorithm.

关键词： Clustering scheme VANET FastPAM

Hydrogen effect on the mechanical behaviour and microstructural features of a Fe-Mn-C twinning induced plasticity steel

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International Journal of Minerals,Metallurgy and Materials 2021年第5期28卷 835-846页

作者： Xiaofei Guo Stefan Zaefferer fady Archie Wolfgang Bleck Steel Institute RWTH Aachen UniversityIntze-str.1Aachen 52072Germany Max-Planck-Institut für Eisenforschung GmbH Max-Planck-Straße 1Düsseldorf 40237Germany NLMK Europe Eutelis-Platz 2Ratingen 40878Germany

The influences of hydrogen on the mechanical properties and the fracture behaviour of Fe-22Mn-0.6C twinning induced plasticity steel have been investigated by slow strain rate tests and fractographic *** steel showed high susceptibility to hydrogen embrittlement,which led to 62.9%and 74.2%reduction in engineering strain with 3.1 and 14.4 ppm diffusive hydrogen,*** fracture surfaces revealed a transition from ductile to brittle dominated fracture modes with the rising hydrogen *** underlying deformation and fracture mechanisms were further exploited by examining the hydrogen effects on the dislocation substructure,stacking fault probability,and twinning behaviour in pre-strained slow strain rate test specimens and notched tensile specimens using coupled electron channelling contrast imaging and electron backscatter diffraction *** results reveal that the addition of hydrogen promotes planar dislocation structures,earlier nucleation of stacking faults,and deformation twinning within those grains which have tensile axis orientations close to//rolling direction and//rolling *** developed twin lamellae result in strain localization and micro-voids at grain boundaries and eventually lead to grain boundary decohesion.

关键词： twinning induced plasticity steel hydrogen mechanical behaviour dislocation twinning electron channelling contrast imaging

Liver transplantation for hepatocellular carcinoma:an update

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Hepatobiliary & Pancreatic Diseases International 2011年第3期10卷 234-242页

作者： Ali Zarrinpar fady Kaldas Ronald W Busuttil Dumont-UCLA Transplant Center Division of Liver and Pancreas Transplantation Department of Surgery David Geffen School of Medicine at UCLA

BACKGROUND: Hepatocellular carcinoma (HCC) is a heterogeneous malignancy with multiple etiologies, high incidence, and high mortality. The standard surgical management for patients with HCC consists of locoregional ablation, surgical resection, or liver transplantation, depending on the background state of the liver. Eighty percent of patients initially presenting with HCC are unresectable, either due to the extent of tumor or the level of underlying hepatic dysfunction. While in patients with no evidence of cirrhosis and good hepatic function resection has been the surgical treatment of choice, it is contraindicated in patients with moderate to severe cirrhosis. Liver transplantation is the optimal surgical treatment. DATA SOURCES: PubMed search of recent articles (from January 2000 to March 2011) was performed looking for relevant articles about hepatocellular carcinoma and its treatment. Additional articles were identified by evaluating references from selected articles. RESULTS: Here we review criteria for transplantation, the types, indications, and role of locoregional therapy in treating the cancer and in downstaging for possible later transplantation. We also summarize the contribution of immunosuppression and adjuvant chemotherapy in the management and prevention of HCC recurrence. Finally we discuss recent advances in imaging, tumor biology, and genomics as we delineate the remaining challenges for the diagnosis and treatment of this disease. CONCLUSIONS: Much can be improved in the diagnosis and treatment of HCC. A great challenge will be to improve patient selection to criteria based on tumor biology. Another will be to incorporate systemic agents post-operatively in patients at high risk for recurrence, paying close attention to efficacy and safety. The future direction of the effort in treating HCC will be to stimulate prospective trials, develop molecular imaging of lymphovascular invasion, to improve recipient selection, and to investigate biomarkers

关键词： liver transplantation hepatocellular carcinoma liver neoplasm downstaging immunosuppression locoregional therapy

Coherent passive optical network for 5G and beyond transport

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Optoelectronics Letters 2021年第9期17卷 546-551页

作者： Waseem W.Shbair fady I.El-Nahal KN Group Dublin D22 YP38Ireland Islamic University of Gaza Gaza P.O.Box 108Palestine

Building low-latency and high-capacity optical networks is vital for new high-speed cellular *** wavelength division multiplexing passive optical networks(WDM-PONs)are expected to play a key role in these *** this article,an overview of PON technologies for the 5 th generation(5 G)transport systems has been ***,a modified scheme based on coherent WDM-PON has been investigated using a dual polarization quadrature phase shift keying(DP-QPSK)*** aim of the scheme is to build a 1600 Gbit/s network that will be used in the construction of the transport architecture of 5 G and beyond cellular networks either in mobile front haul(MFH)or mobile back haul(MBH).The results indicate that the proposed scheme offers a promising solution for future 5 G transport systems.

关键词： passive network beyond

Coherent optical communication systems based on orthogonal frequency division multiplexing

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Optoelectronics Letters 2020年第4期16卷 303-305页

作者： fady I.El-Nahal Nabih M.Abualoff Institute for Communications Engineering Technical University of MunichMunich 80290Germany

Coherent optical orthogonal frequency division multiplexing(CO-OFDM)is considered as a key solution for long haul optical fiber communication systems thanks to its high spectral efficiency and robustness against chromatic *** have investigated a CO-OFDM based on quadrature phase shift keying(QPSK)-OFDM and 16 quadrature amplitude modulation(16 QAM)-OFDM over 500 km uncompensated fiber *** simulation results show that the proposed system is a promising solution to meet the aggregate data rate demands cost effectively in future high-speed optical communication systems.

关键词： communication optical fiber

2 Tbit/s based coherent wavelength division multiplexing passive optical network for 5G transport

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Optoelectronics Letters 2021年第5期17卷 308-312页

作者： Abed Barzaq Isaac Ashour Waseem Shbair fady IEl-Nahal Islamic University of Gaza GazaPalestine Al-Quds Open University GazaPalestine KN Circet Dublin D22 YP38Ireland

Future high-speed mobile communication systems require low latency and high capacity *** wavelength division multiplexing(WDM)passive optical network(PON)scheme is expected to play a vital role in these *** this paper,coherent WDM-PON scheme based on dual-polarization 16-quadrature amplitude modulation(DP-16 QAM)transceiver has been *** aim of this scheme is to build a 2 Tbit/s(125 Gbit/s/λ×16 wavelengths)network that will be used in the construction of the transport architecture of fifth generation(5 G)and beyond 5 G(B5 G)cellular networks either in mobile front haul(MFH)or mobile back haul(MBH).The results indicate that the proposed scheme is very adequate for both 5 G and B5 G cellular networks requirements.

关键词： WDM QAM Tbit/s based coherent wavelength division multiplexing passive optical network for 5G transport PON

Minimally invasive spleen-preserving distal pancreatectomy: Does splenic vessel preservation have better postoperative outcomes? A systematic review and meta-analysis

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Hepatobiliary & Pancreatic Diseases International 2015年第4期14卷 346-353页

作者： fady Elabbasy Rahul Gadde Mena M Hanna Danny Sleeman Alan Livingstone Danny Yakoub Division of Surgical Oncology Department of Surgery Sylvester Comprehensive Cancer Center University of Miami-Miller School of Medicine

BACKGROUND： Minimally invasive spleen-preserving distal pancreatectomy （SPDP） can be performed with either splenic vessel preservation （SVP） or resection [Warshaw procedure （WP）]. The aim of this study was to evaluate the postoperative clinical outcomes of patients undergoing both methods. DATA SOURCES： Database search of PubMed, Embase, Scopus, Cochrane, and Google Scholar was performed （2000-2014）; key bibliographies were reviewed. Qualified studies compar- ing patients undergoing SPDP with either SVP or WP, and as- sessing postoperative complications were included. Calculated pooled risk ratio （RR） with the corresponding 95% confidence interval （CI） by random effects methods were used in the meta-analyses. RESULTS： The search yielded 215 studies, of which only 14 observational studies met our selection criteria. The studies included 943 patients in total; 652 （69%） underwent SVP and 291 （31%） underwent WP. Overall, there was a lower incidence of splenic infarction （RR=0.17; 95% Ch 0.09-0.33; P〈0.001）, gastric varices （RR=0.16; 95% Ch 0.05-0.51; P=0.002）, and intra/postoperative splenectomy （RR=0.20; 95% Ch 0.08-0.49; P〈0.001） in the SVP group. There was no difference in in- cidence of pancreatic fistula （WP vs SVP, 23.6% vs 22.9%;P=0.37）, length of hospital stay, operative time or blood loss. There was moderate cross-study heterogeneity. CONCLUSIONS： SVP is a safe, efficient and feasible technique that may be used to preserve the spleen. WP may be more suit- able for large tumors dose to the splenic hilum or those associ- ated with splenomegaly. Randomized clinical trials are justified to examine the long-term benefits of SVP-SPDP.

关键词： splenic infarction spleen-preserving distal pancreatectomy splenic vessel preservation Warshaw procedure gastric varices

Radio Optical Network Simulation Tool (RONST)

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Computers, Materials & Continua 2022年第5期71卷 3685-3702页

作者： Yasmine IAbdelhak fady Kamel Moustafa Hafez Hussein EKotb Haitham AOmran Tawfik Ismail Hassan Mostafa Department of Electronics and Communications Faculty of EngineeringMansoura UniversityDakahlia35516Egypt Nanotechnology and Nanoelectronics Program Zewail City of Science and TechnologyGiza12578Egypt Department of Electronics and Communications Faculty of EngineeringCairo UniversityGiza12613Egypt Department of Electronics and Communications Faculty of EngineeringAin Shams UniversityCairo11566Egypt Laboratory of Micro Optics Faculty of Information Engineering and TechnologyGerman University in Cairo11835CairoEgypt National Institute of Laser Enhanced Sciences Cairo UniversityGiza12613Egypt Wireless Intelligent Networks Center(WINC) Nile UniversityGiza12677Egypt

This paper presents a radio optical network simulation tool(RONST)for modeling optical-wireless *** a typical optical and electrical chain environment,performance should be optimized concurrently before system *** a result,simulating such systems turns out to be a multidisciplinary *** governing equations are incompatible with co-simulation in the traditional environments of existing software(SW)*** ultra-wideband(UWB)technology is an ideal candidate for providing high-speed short-range access for wireless *** limited wireless reach of this technology is a significant limitation.A feasible solution to the problem of extending UWB signals is to transmit these signals to endusers via optical *** concept implies the need for the establishment of a dependable environment for studying such ***,the essential novelty of the proposed SW is that it provides designers,engineers,and researchers with a dependable simulation framework that can accurately and efficiently predict and/or optimize the behavior of such systems in a single optical-electronic simulation ***,it is supported by a strong mathematical foundation with integrated algorithms to achieve broad flexibility and low computational *** validate the proposed tool,RONST was deployed on an ultra-wideband over fiber(UWBoF)*** bit error rate(BER)has been calculated over a UWBoF system,and there is good agreement between the experimental and simulated results.

关键词： Optical-wireless systems mathematical modelling techniques opto-electronic software tools ultra-wide band over fiber systems(UWBoF)