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Enhancing Bandwidth Utilization of IP Telephony Over IPv6 Networks

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Computer Systems Science & Engineering 2023年第2期44卷 1039-1049页

作者： Hani Al-mimi Yousef Alrabanah mosleh m.abualhaj Sumaya N.Al-khatib Al-Zaytooanh University of Jordan Faculty of Science and Information TechnologyDepartment of CybersecurityAmman11733Jordan Al-Ahliyya Amman University Faculty of Information TechnologyDepartment of Software EngineeringAmman19328Jordan Al-Ahliyya Amman University Faculty of Information TechnologyDepartment of Networks and Information SecurityAmman19328Jordan

The demand for the telecommunication services,such as IP telephony,has increased dramatically during the COVID-19 pandemic *** tele-phony should be enhanced to provide the expected *** of the issues that should be investigated in IP telephony is bandwidth *** telephony pro-duces very small speech samples attached to a large packet *** header of the IP telephony consumes a considerable share of the bandwidth allotted to the IP *** wastes the network's bandwidth and inﬂuences the IP telephony *** paper proposes a mechanism(called Smallerize)that reduces the bandwidth consumed by both the speech sample and the *** is achieved by assembling numerous IP telephony packets in one header and use the header'sﬁelds to carry the speech *** metrics have been used to measure the achievement Smallerize *** number of calls has been increased by 245.1%compared to the typical *** bandwidth saving has also reached 68%with the G.28 ***,Smallerize is a possible mechanism to enhance bandwidth utilization of the IP telephony.

关键词： –IP telephony codec bandwidth utilization IPv6

Down to Zero Size of VoIP Packet Payload

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Computers, materials & Continua 2021年第7期68卷 1271-1283页

作者： mosleh m.abualhaj Qusai Y.Shambour Abdelrahman H.Hussein Qasem m.Kharma Faculty of Information Technology Al-Ahliyya Amman UniversityAmmanJordan

Voice over Internet Protocol(VoIP)is widely used by companies,schools,universities,and other ***,VoIP faces many issues that slow down its *** important issue is poor utilization of the VoIP service network bandwidth,which results from the large header of the VoIP *** objective of this study is to handle this poor utilization of the network ***,this study proposes a novel method to address this large header overhead *** proposed method is called zero size payload(ZSP),which aims to reemploy and use the header information(fields)of the VoIP packet that is dispensable to the VoIP service,particularly the unicast IP voice *** general,these fields are used to carry the VoIP packet ***,the size of the payload is reduced to save *** performance estimation results of the proposed ZSP method showed a considerable improvement in the bandwidth utilization of the VoIP *** example,the saved bandwidth in the tested scenario with the G.723.1,G.729,and LPC codecs reached 32%,28%,and 26%respectively.

关键词： Voice over internet protocol VoIP protocols bandwidth utilization

multi-indicator Active Queue management method

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Computer Systems Science & Engineering 2021年第8期38卷 251-263页

作者： mosleh m.abualhaj Abdelrahman H.Hussein Qasem m.Kharma Qusai Y.Shambour Faculty of Information Al-Ahliyya Amman UniversityAmman19328Jordan

A considerable number of applications are running over IP *** increased the contention on the network resource,which ultimately results in *** queue management(AQm)aims to reduce the serious consequences of network congestion in the router buffer and its negative effects on network *** methods implement different techniques in accordance with congestion indicators,such as queue length and average queue *** performance of the network is evaluated using delay,loss,and *** gap between congestion indicators and network performance measurements leads to the decline in network *** this study,delay and loss predictions are used as congestion indicators in a novel stochastic approach for *** proposed method estimates the congestion in the router buffer and then uses the indicators to calculate the dropping probability,which is responsible for managing the router *** experimental results,based on two sets of experiments,have shown that the proposed method outperformed the existing benchmark algorithms including RED,ERED and BLUE *** instance,in the first experiment,the proposed method resides in the third-place in terms of delay when compared to the benchmark *** addition,the proposed method outperformed the benchmark algorithms in terms of packet loss,packet dropping,and packet ***,the proposed method outperformed the benchmark algorithms because it preserves packet loss while maintaining reasonable queuing delay.

关键词： Congestion control network performance active queue management

Effective Hybrid Content-Based Collaborative Filtering Approach for Requirements Engineering

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Computer Systems Science & Engineering 2022年第1期40卷 113-125页

作者： Qusai Y.Shambour Abdelrahman H.Hussein Qasem m.Kharma mosleh m.abualhaj Faculty of Information Technology Al-Ahliyya Amman UniversityAmman19328Jordan

Requirements engineering(RE)is among the most valuable and critical processes in software *** quality of this process significantly affects the success of a software *** important step in RE is requirements elicitation,which involves collecting project-related requirements from different *** of reusable requirements are typically important sources of an increasing number of reusable software ***,the process of searching such repositories to collect valuable project-related requirements is time-consuming and difficult to perform *** systems have been widely recognized as an effective solution to such ***,this study proposes an effective hybrid content-based collaborative filtering recommendation *** proposed approach will support project stake-holders in mitigating the risk of missing requirements during requirements elicitation by identifying related requirements from software requirement *** experimental results on the RALIC dataset demonstrate that the proposed approach considerably outperforms baseline collaborative filtering-based recom-mendation methods in terms of prediction accuracy and coverage in addition to mitigating the data sparsity and cold-start item problems.

关键词： Requirements engineering recommender systems requirements elicitation collaborative filtering content-based filtering

Effect of divalent cations(Co^(2+) and Ni^(2+)) on microstructure,physical properties and application of NdFeO_(3)

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Journal of Rare Earths 2025年第1期43卷 89-97,I0004页

作者： m.m.Arman materials Science Lab(1) Physics DepartmentFaculty of ScienceCairo UniversityGiza12613Egypt

The nanocrystalline samples Nd_(1-x)m_(x)FeO_(3)(x=0.0 and 0.1;m:Co^(2+)and Ni^(2+))were prepared using the citrate combustion *** X-ray diffraction(XRD)pattern confirmed that the nanoparticles were synthesized in an orthorhombic *** particle size of Nd_(1-x)m_(x)FeO_(3) is in the range of 29-59 *** selected area electron diffraction(SAED)indicates the samples were prepared in a polycrystalline *** samples Nd_(1-x)m_(x)FeO_(3)(x=0.0 and 0.1;m:Co^(2+)and Ni^(2+))have anti ferromagnetic *** Fe^(3+)spins are aligned antiparallel,forming the antiferromagnetic(AFm)properties,which are affected by many factors such as the bond angle between the Fe^(3+)(Fe^(3+)-O_(2)--Fe^(3+))and the Dzyaloshinskii-moriya(D-m)*** doping of Co^(2+)and Ni^(2+)ions in NdFeO_(3) enhances the magnetic properties of the NdFeO_(3).The saturation magnetization(ms)of Nd_(0.90)Co_(0.10)FeO_(3) increases 1.8times more than that of NdFeO_(3).The exchange bias field(HEX)of the Co-doped sample is two times greater than that of NdFeO_(3).The magnetic anisotropy constant(K)of the 10%Co-doped sample increases by 11 factors compared to that of NdFeO_(3).The Tauc plot illustrates that the samples have a direct optical *** divalent cation substitution(Co^(2+)and Ni^(2+))decreases the optical band gap of NdFeO_(3),leading to the recommendation of using the samples Nd_(0.90)Co_(0.10)FeO_(3) and Nd_(0.90)Ni_(0.10)FeO_(3) in photocatalysis of dye degradation from *** removal efficiencies of Cr6+at pH=6 are 88.06%,85.54%,and 85.52%for the samples NdFeO_(3),Nd_(0.90)Co_(0.10)FeO_(3),and Nd_(0.90)Ni_(0.10)FeO_(3),*** Freundlich isotherm mode is the best-fit model for NdFeO_(3) to adsorb Cr6+ions from aqueous solutions.

关键词： Optical properties Nanoparticles magnetic properties Perovskites Removal efficiency Rareearths

Fabrication of an r-Al_2Ti intermetallic matrix composite reinforced with α-Al_2O_3 ceramic by discontinuous mechanical milling for thermite reaction

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International Journal of minerals,metallurgy and materials 2014年第10期21卷 1037-1043页

作者： A.mosleh m.Ehteshamzadeh R.Taherzadeh mousavian Department of materials Science and Engineering Shahid Bahonar University of Kerman Department of metallurgy Zanjan Branch Islamic Azad University

In this study, a powder mixture with an Al/TiO2 molar ratio of 10/3 was used to form an r-Al2Ti intermetallic matrix composite （ImC） reinforced with α-Al2O3 ceramic by a novel milling technique, called discontinuous mechanical milling （Dmm） instead of milling and ignition of the produced thermite. The results of energy dispersive X-ray spectroscopy （EDX） and X-ray diffraction （XRD） of samples with varying milling time indicate that this fabrication process requires considerable mechanical energy. It is shown that Al2Ti-α-Al2O3 ImC with small grain size was produced by Dmm after 15 h of ball milling. Peaks for γ-TLA1 as well as Al2Ti and Al2O3 are observed in XRD patterns after Dmm followed by heat treatment. The microhardness of the Dmm-treated composite produced after heat treatment was higher than Hv 700.

关键词： composite materials intermetallics alumina titanium aluminide ball milling thermite reaction process

Nonlinear forced vibration in a subcritical regime of a porous functionally graded pipe conveying fluid with a retaining clip

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Applied mathematics and mechanics(English Edition) 2025年第1期46卷 101-122页

作者： m.GHOLAmI m.EFTEKHARI Department of mechanical Engineering Shahid Bahonar University of Kerman

This study examines the nonlinear behaviors of a clamped-clamped porous pipe made of a functionally graded material(FGm) that conveys fluids and is equipped with a retaining clip, focusing on primary resonance and subcritical dynamics. The nonlinear governing equations for the FGm pipe are derived by the extended Hamilton's principle, and subsequently discretized through the application of the Galerkin *** direct method of multi-scales is then used to solve the derived equations. A thorough analysis of various parameters, including the clip stiffness, the power-law index, the porosity, and the clip location, is conducted to gain a comprehensive understanding of the system's nonlinear dynamics. Through the analysis of the first natural frequency, the study highlights the influence of the flow velocity and the clip stiffness, while the comparisons with metallic pipes emphasize the role of FGm composition. The examination of the forced response curves reveals saddle-node bifurcations and their dependence on parameters such as the detuning parameter and the power-law index, offering valuable insights into the system's nonlinear resonant behavior. Furthermore, the frequency-response curves illustrate the hardening nonlinearities influenced by factors such as the porosity and the clip stiffness, revealing nuanced effects on the system response and resonance characteristics. This comprehensive analysis enhances the understanding of nonlinear behaviors in FGm porous pipes with a retaining clip, providing key insights for practical engineering applications in system design and optimization.

关键词： functionally graded material (FGm) pipe conveying fluid O175.2 porosity primary resonance retaining clip subcritical regime

Honeycomb-spiderweb-inspired self-similar hybrid cellular structures for impact applications

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Defence Technology(防务技术) 2025年第1期43卷 182-200页

作者： K.Tewari m.K.Pandit m.m.mahapatra P.R.Budarapu School of mechanical Sciences Indian Institute of Technology BhubaneswarBhubaneswar752050India

Inspired by nature's self-similar designs,novel honeycomb-spiderweb based self-similar hybrid cellular structures are proposed here for efficient energy absorption in impact *** energy absorption is enhanced by optimizing the geometry and topology for a given *** proposed hybrid cellular structure is arrived after a thorough analysis of topologically enhanced self-similar *** optimized cell designs are rigorously tested considering dynamic loads involving crush and high-velocity bullet ***,the influence of thickness,radial connectivity,and order of patterning at the unit cell level are also *** maximum crushing efficiency attained is found to be more than 95%,which is significantly higher than most existing traditional *** on,the first and second-order hierarchical self-similar unit cell designs developed during crush analysis are used to prepare the cores for sandwich *** tests are performed on the developed sandwich structures using the standard 9-mm *** influence of multistaging on impact resistance is also investigated by maintaining a constant total thickness and mass of the sandwich ***,in order to avoid layer-wise weak zones and hence,attain a uniform out-of-plane impact strength,off-setting the designs in each stage is *** sandwich structures with first and second-order self-similar hybrid cores are observed to withstand impact velocities as high as 170 m/s and 270 m/s,respectively.

关键词： Sandwich structures Honeycomb-spider web inspired Self-similar hierarchy Crush analysis High-velocity impact Strong and weak zones multistaging

Discovering causal models for structural,construction and defense-related engineering phenomena

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Defence Technology(防务技术) 2025年第1期43卷 60-79页

作者： m.Z.Naser School of Civil&Environmental Engineering and Earth Sciences(SCEEES) Clemson UniversityClemsonSouth Carolina 29634USA The Artificial Intelligence Research Institute for Science and Engineering(AIRISE) Clemson UniversityClemsonSouth Carolina 29634USA

Causality,the science of cause and effect,has made it possible to create a new family of *** models are often referred to as causal *** those of mathematical,numerical,empirical,or machine learning(mL)nature,causal models hope to tie the cause(s)to the effect(s)pertaining to a phenomenon(i.e.,data generating process)through causal *** paper presents one of the first works at creating causal models in the area of structural and construction *** this end,this paper starts with a brief review of the principles of causality and then adopts four causal discovery algorithms,namely,PC(Peter-Clark),FCI(fast causal inference),GES(greedy equivalence search),and GRa SP(greedy relaxation of the sparsest permutation),have been used to examine four phenomena,including predicting the load-bearing capacity of axially loaded members,fire resistance of structural members,shear strength of beams,and resistance of walls against impulsive(blast)*** from this study reveal the possibility and merit of discovering complete and partial causal ***,this study also proposes two simple metrics that can help assess the performance of causal discovery algorithms.

关键词： Causality Causal discovery Directed acyclic graphs machine learning metrics