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2006

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Articles 1021 - 1050 of 3391

Full-Text Articles in Engineering

Generalized Perceptual Linear Prediction (Gplp) Features For Animal Vocalization Analysis, Patrick J. Clemins, Michael T. Johnson Jul 2006

Generalized Perceptual Linear Prediction (Gplp) Features For Animal Vocalization Analysis, Patrick J. Clemins, Michael T. Johnson

Dr. Dolittle Project: A Framework for Classification and Understanding of Animal Vocalizations

A new feature extraction model, generalized perceptual linear prediction (gPLP), is developed to calculate a set of perceptually relevant features for digital signal analysis of animalvocalizations. The gPLP model is a generalized adaptation of the perceptual linear prediction model, popular in human speech processing, which incorporates perceptual information such as frequency warping and equal loudness normalization into the feature extraction process. Since such perceptual information is available for a number of animal species, this new approach integrates that information into a generalized model to extract perceptually relevant features for a particular species. To illustrate, qualitative and quantitative comparisons are made …


Development And Testing Of A Low-Cost Condensation Detection System, Michael D. Montross, George A. Duncan, Richard S. Gates Jul 2006

Development And Testing Of A Low-Cost Condensation Detection System, Michael D. Montross, George A. Duncan, Richard S. Gates

Biosystems and Agricultural Engineering Faculty Publications

A condensation sensing and control system was designed to detect condensation using a commercially available leaf wetness sensor (LWS). The leaf wetness sensor was a variable resistance grid-type that responded to moisture on the surface. A circuit was developed to compare the LWS voltage output to a user specified reference voltage, and operate a relay for possible switching of a humidity control device (for example a fan and/or heater). The condensation detection system operation was validated in an environmental chamber in the laboratory using a heat exchanger and water bath. Condensate was immediately detected when the plate was cooled below …


Optimization Of The Blank Holder Force Using Finite Elements And Genetic Algorithms With Application To Deep Drawing And Draw Bending, Lucas Aaron Levitsky Jul 2006

Optimization Of The Blank Holder Force Using Finite Elements And Genetic Algorithms With Application To Deep Drawing And Draw Bending, Lucas Aaron Levitsky

Archived Theses and Dissertations

No abstract provided.


Hysteresis And Delta Modulation Control Of Converters Using Sensorless Current Mode, Jonathan W. Kimball, Philip T. Krein, Yongxiang Chen Jul 2006

Hysteresis And Delta Modulation Control Of Converters Using Sensorless Current Mode, Jonathan W. Kimball, Philip T. Krein, Yongxiang Chen

Electrical and Computer Engineering Faculty Research & Creative Works

Sensorless current mode (SCM) is a control formulation for dc-dc converters that results in voltage-source characteristics, excellent open-loop tracking, and near-ideal source rejection. Hysteresis and delta modulation are well-known, easy-to-construct large-signal methods for switched systems. Combining either large-signal method with SCM creates a controller that is simpler and more robust than a pulse-width modulation (PWM) based controller. The small-signal advantages of PWM-based SCM are retained and expanded to include converter response to large-signal disturbances. These approaches can be used with any converter topology over a broad range of operating conditions. In the present work, hysteresis and delta modulation SCM controllers …


Temporal Calcium Response Of Jurkat Cells To Nanosecond Pulsed Electric Fields, Shaka Shakar Scarlett Jul 2006

Temporal Calcium Response Of Jurkat Cells To Nanosecond Pulsed Electric Fields, Shaka Shakar Scarlett

Electrical & Computer Engineering Theses & Dissertations

Nanosecond pulsed electric fields (nsPEF) of megavolt per meter field strengths can interact with subcellular structures [1] and consequently trigger a variety of biological events. The exposure can induce apoptosis, as well as an array of differential "sub-lethal effects." One of the most sensitive and immediate responses is the increase in intracellular calcium concentration in pulsed cells [2], [3][4].We investigated the response of Jurkat cells (a human leukemic cell line) to nsPEFs of 60 ns duration and field strengths from 25 tol00 kV/cm. The development of the induced calcium response in individual cells was studied by spinning-disc confocal microscopy with …


Spacecraft Trajectory Design For Short Duration Near Earth Asteroid Missions, Synthia Mirlin Findlay Jul 2006

Spacecraft Trajectory Design For Short Duration Near Earth Asteroid Missions, Synthia Mirlin Findlay

Mechanical & Aerospace Engineering Theses & Dissertations

Design of orbital trajectories using patched conic approximation methodology for short duration missions to newly detected, incoming near Earth asteroids, which are on close approach trajectories with Earth, is the focus of this thesis. The primary purpose for such missions is two fold. First, near Earth asteroids provide unique mission opportunities for solar system science where the celestial body of interest transits to Earth proximity and is studied in situ by probes having short duration trajectories, rather than sending long distance probes to the celestial body. Second, improved characterization of asteroid properties, compositions, and orbital states for reduction of uncertainties …


Unsteady Numerical Analysis Of A 2-Dimensional, Hydrogen Fueled, Air-Breathing Dual Mode Scramjet Engine, Nathan John Luetke Jul 2006

Unsteady Numerical Analysis Of A 2-Dimensional, Hydrogen Fueled, Air-Breathing Dual Mode Scramjet Engine, Nathan John Luetke

Mechanical & Aerospace Engineering Theses & Dissertations

Upstream interaction in a transient two-dimensional dual-mode scramjet engine is examined. This research is performed to compare completed and verified steady results with unsteady results in order to have a better understanding of the flow field. The flow is solved numerically with a Mach 2.5 free stream and sonic normal injection of hydrogen fuel emanating from facing walls while no symmetry assumptions were made. The free stream is modeled as vitiated air in order to produce comparable flight enthalpies and stagnation properties at the combustor inlet during flight conditions of approximately Mach 7. The vitiated stream consists of water vapor …


Life Cycle Impact Assessment Method For Early Design Phase Of Industrial Products, Harpreet Singh Multani Jul 2006

Life Cycle Impact Assessment Method For Early Design Phase Of Industrial Products, Harpreet Singh Multani

Mechanical & Aerospace Engineering Theses & Dissertations

The objective of this thesis is to develop a simplified life cycle impact assessment method that can reliably and quickly provide the values of Eco-indicator 99 single score, the Eco-indicator damage categories score (human health, ecosystem quality, resource depletion), environmental impacts like global warming, ozone depletion, acidification, eutrophication, photochemical oxidants potential of the product/process, which could be used in the initial design stages for alternative design comparisons and product improvements, thus leading towards green manufacturing.

To achieve this, a variety of products have been chosen and the life cycle inventory data is gathered from the environmental product declarations that are …


Statistical Interpretation Of Mohr-Coulomb Theory As Applied To Fracture In Brittle Materials Containing Cracks, Mudit J. Monsi Jul 2006

Statistical Interpretation Of Mohr-Coulomb Theory As Applied To Fracture In Brittle Materials Containing Cracks, Mudit J. Monsi

Mechanical & Aerospace Engineering Theses & Dissertations

Fracture in brittle materials containing pre-existing cracks was studied. The probability of of crack growth under both shear and tensile stresses was determined for an arbitrary distribution of crack sizes. Two different crack orientation distributions, random and uniform, as well as friction were also taken into account. The material's reliability was assumed to depend on the number of active cracks at a particular stress level, and this was expressed as an arbitrary 2-parameter Weibull distribution. Two new and efficient methods for calculating crack growth probabilities based on spherical triangles and spherical caps were developed. They utilized normalized stress coordinates and …


Dissolution, Reactor, And Environmental Behavior Of Zro 2 -Mgo Inert Fuel Matrix Neutronic Evaluation Of Mgo-Zro2 Inert Fuels, E. Fridman, A. Galperin, E. Shwageraus Jul 2006

Dissolution, Reactor, And Environmental Behavior Of Zro 2 -Mgo Inert Fuel Matrix Neutronic Evaluation Of Mgo-Zro2 Inert Fuels, E. Fridman, A. Galperin, E. Shwageraus

Fuels Campaign (TRP)

In the second year of the “Dissolution, Reactor, and Environmental Behavior of ZrO2-MgO Inert Fuel Matrix” project initiated and directed by UNLV, the Ben-Gurion University (BGU) group research was focused on the development of practical PWR core nuclear design fully loaded with Reactor Grade (RG) Pu fuel incorporated in fertile free matrix. The design strategy was based on the basic feasibility study results performed at BGU in the Year 1 of the project.


Advancements In Frameworks For Educational Games Through Sound Software Engineering Principles., Christy M. Bogard Jul 2006

Advancements In Frameworks For Educational Games Through Sound Software Engineering Principles., Christy M. Bogard

Electronic Theses and Dissertations

Educational games have steadily entered classrooms as a means of challenging advanced students and tutoring those lacking comprehension. However, without adequate educational benefits, instructors are struggling to continually justify the marginal value added of using these programs. It is the intent of this thesis to demonstrate that sound software engineering principles can improve the framework of educational games. First, the core framework requirements of computer-based educational games are outlined. Current educational games are then evaluated based on their ability to meet these requirements. From this analysis, necessary architectural changes are recommended to best facilitate future game advancements. Finally, to demonstrate …


Bs News Jul 2006

Bs News

Building Services Engineering

No abstract provided.


Evaluation Of Wildlife Reflectors In Reducing Vehicle-Deer Collisions On Indiana Interstate 80/90, Sedat Gulen, George P. Mccabe, Ira Rosenthal, Samuel E. Wolfe, Virgil L. Anderson Jul 2006

Evaluation Of Wildlife Reflectors In Reducing Vehicle-Deer Collisions On Indiana Interstate 80/90, Sedat Gulen, George P. Mccabe, Ira Rosenthal, Samuel E. Wolfe, Virgil L. Anderson

JTRP Technical Reports

The Indiana Department of Transportation is committed to reducing vehicle-deer collision incidents on the Indiana Interstate I-80/90 as well as on the other roads. Very few of the studies to reduce vehicle-deer collisions incorporated any sound and complete statistical design. Some states (California, Colorado, Maine, Ontario-Canada, Washington State and Wyoming) have found that the use of wildlife reflectors did not reduce vehicle-deer collisions. However, some other states (British Columbia-Canada, Iowa, Minnesota, Oregon, Washington State and Wisconsin) found that the use of wildlife reflectors did reduce vehicle-deer collisions.

The main objective of this experimental study is to evaluate the effectiveness of …


Infrared Broadband 50%-50% Beam Splitters For S-Polarized Light, R. M.A. Azzam Jul 2006

Infrared Broadband 50%-50% Beam Splitters For S-Polarized Light, R. M.A. Azzam

Electrical Engineering Faculty Publications

Prisms and slabs made of high-refractive-index materials such as ZnSe, Ge, and Si can be designed as broadband, 50%-50%, beam splitters (BSs) for obliquely incident s- polarized light in the near- and mid-IR. The beam-splitting face of the prism or slab is uncoated, while the exit face is antireflection coated. The split beams travel in orthogonal directions when light is incident at the Brewster angle. A novel design is also described that uses Brewster-angle reflection at the SiO2-Si interface to achieve a 50%-50%s-polarization BS over the 1.2-3.5 μm spectral range. Such s-polarization BSs are particularly suited for interferometry …


Development Of An Electro-Mechanical System To Identify & Map Adverse Soil Compaction Using Gis&Gps, Santosh Pitla, L. G. Wells Jul 2006

Development Of An Electro-Mechanical System To Identify & Map Adverse Soil Compaction Using Gis&Gps, Santosh Pitla, L. G. Wells

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

A stand-alone electro-mechanical system with a 32-inch disc coulter was developed and tested to identify soil compaction in a 1-acre field located at the University of Kentucky Animal Research Center (UKARC). The system was evaluated by making four passes in the square grid cell. With the aid of hydraulic actuation, the coulter oscillated between depths of 100mm (4-in) and 330mm (13-in) as it moved forward and recorded the vertical impedance force given by the soil continuously. Forty standard soil cone penetrometer measurements along the diagonals to a depth of 400mm (16-in) were taken and the average cone indices (MPa) at …


Relationships Between Pacific And Atlantic Ocean Sea Surface Temperatures And U.S. Streamflow Variability, Glenn A. Tootle, Thomas C. Piechota Jul 2006

Relationships Between Pacific And Atlantic Ocean Sea Surface Temperatures And U.S. Streamflow Variability, Glenn A. Tootle, Thomas C. Piechota

Civil and Environmental Engineering and Construction Faculty Research

An evaluation of Pacific and Atlantic Ocean sea surface temperatures (SSTs) and continental U.S. streamflow was performed to identify coupled regions of SST and continental U.S. streamflow variability. Both SSTs and streamflow displayed temporal variability when applying the singular value decomposition (SVD) statistical method. Initially, an extended temporal evaluation was performed using the entire period of record (i.e., all years from 1951 to 2002). This was followed by an interdecadal-temporal evaluation for the Pacific (Atlantic) Ocean based on the phase of the Pacific Decadal Oscillation (PDO) (Atlantic Multidecadal Oscillation (AMO)). Finally, an extended temporal evaluation was performed using detrended SST …


Decentralized Cooperative Aerial Surveillance Using Fixed-Wing Miniature Uavs, Randal Beard, Derek Kingston, Timothy W. Mclain, Derek Nelson Jul 2006

Decentralized Cooperative Aerial Surveillance Using Fixed-Wing Miniature Uavs, Randal Beard, Derek Kingston, Timothy W. Mclain, Derek Nelson

Faculty Publications

Numerous applications require aerial surveillance. Civilian applications include monitoring forest fires, oil fields and pipelines, and tracking wildlife. Applications to homeland security include border patrol and monitoring the perimeter of nuclear power plants. Military applications are numerous. The current approach to these applications is to use a single manned vehicle for surveillance. However, manned vehicles are typically large and expensive. In addition, hazardous environments and operator fatigue can potentially threaten the life of the pilot. Therefore, there is a critical need for automating aerial surveillance using unmanned air vehicles (UAVs). This paper gives an overview of a cooperative control strategy …


A Stochastic Production Cost Model For Remanufacturing Systems, Gaurang S. Patel Jul 2006

A Stochastic Production Cost Model For Remanufacturing Systems, Gaurang S. Patel

Theses and Dissertations - UTB/UTPA

Growing environmental concern throughout this decade coupled with enforced legislation, customer expectations and economic incentives have forced increasing number of manufacturers to take back their products from end user. Managing this reverse flow of products is called reverse logistics. The stochastic nature of returned products complicates the production planning for remanufacturing systems in reverse logistics. In this thesis a stochastic production cost model, considering various costs associated under different situations for remanufacturing systems of returned products is developed. A search algorithm method is recommended to determine optimal production run size, production rate and space for remanufacturing systems in reverse logistics. …


Soft-Started Induction Motor Modeling And Heating Issues For Different Starting Profiles Using A Flux Linkage Abc Frame Of Reference, M. G. Solveson, Behrooz Mirafzal, Nabeel Demerdash Jul 2006

Soft-Started Induction Motor Modeling And Heating Issues For Different Starting Profiles Using A Flux Linkage Abc Frame Of Reference, M. G. Solveson, Behrooz Mirafzal, Nabeel Demerdash

Electrical and Computer Engineering Faculty Research and Publications

In order to mitigate the adverse effects of starting torque transients and high inrush currents in induction motors, a popular method is to use electronically controlled soft-starting voltages utilizing series-connected silicon-controlled rectifiers (SCRs). Investigation of semioptimum soft-starting voltage profiles was implemented using a flux linkage ABC frame of reference model of a soft-started three-phase induction motor. A state-space model of the soft-starter thyristor switching sequence for the motor and load was developed and implemented in a time-domain simulation to examine winding heating and shaft stress issues for different starting profiles. Simulation results of line starts and soft starts were compared …


Fractures Of As-Cast Low-Carbon Steels In The Plasticity Degradation Area At High Testing Temperatures, A Ševčík, J Ševčíková Jul 2006

Fractures Of As-Cast Low-Carbon Steels In The Plasticity Degradation Area At High Testing Temperatures, A Ševčík, J Ševčíková

Journal of Metals, Materials and Minerals

The work studies the fractures of low-carbon steels after tensile tests in a temperature interval from ca 1200°C, where a plasticity degradation takes place, up to the liquid phase formation temperature. Statistical analyses of the temperature dependence of the reduction of area were made with the aim to determine integral effects of the chemical composition on the plasticity course. In the plasticity degradation temperature area, intercrystalline fractures occur, which have several morphologies, even within the same steel grade. Besides typical intercrystalline fractures, a fine-grained, interdendritic fracture often occurs. A specific case is the failure of steels in the γ + …


Mechanical Properties Of Skin Wounds After Atropa Belladonna Application In Rats, T Toporcer, T Grendel, B Vidinský, P Gál, J Sabo, R Hudák Jul 2006

Mechanical Properties Of Skin Wounds After Atropa Belladonna Application In Rats, T Toporcer, T Grendel, B Vidinský, P Gál, J Sabo, R Hudák

Journal of Metals, Materials and Minerals

Atropa belladonna is a topical agent used in the treatment of skin wounds in Slovak folk medicine. The aim of this study was to asses the effect of A. belladonna extract on wound tensile strength in Sprague-Dawley rats. Twenty four rats were randomly divided into 3 groups of 8 animals. Two symmetrical skin incisions were performed on the back of each animal and immediately sutured. In the 1st group A. belladonna extract was not applied and the group served as a control. The animals in the 2nd group were treated by daily application of A. Belladonna extract during the first …


Modified Vegetable Oil In Textile Finishing Applications, N Jiratumnukul, P Antarasane Jul 2006

Modified Vegetable Oil In Textile Finishing Applications, N Jiratumnukul, P Antarasane

Journal of Metals, Materials and Minerals

Water-repellent finishing is an important process in textile industries as well as other finishing processes. Coating on the fabric can be used to achieve a substantial water-repellent effect. Using polymeric coatings, however, provided some disadvantages in air and water vapour permeability causing undesirable feelings when wearing. Besides, the fabric treated with polymeric coatings will impart a stiffening appearance, which is undesirable. In this study, water repellents have been prepared from various vegetable oils with different amounts of saturation in fatty acid moiety. Vegetable oil was transesterified with an intermediate fluorinated compound to give modified fatty esters. These fatty esters were …


Energy Based Method For Generation Of Optimum Flight Paths, Michael Jon Acheson Jul 2006

Energy Based Method For Generation Of Optimum Flight Paths, Michael Jon Acheson

Mechanical & Aerospace Engineering Theses & Dissertations

One key to increasing aviation safety and airport efficiency is the proper management of aircraft energy states. Aircraft accident statistics are replete with examples of aircraft that crossed the runway threshold with excessive energy or maintained insufficient energy to reach the runway. This trend has resulted in aircrews that are trained in conservative energy management that trades efficiency for simplicity. Additionally, traditional aircraft flight displays provide limited aircraft energy state cues that do not enable efficient management of aircraft energy states. In this thesis, a method for generating global optimum flight profiles is demonstrated that yields results that can be …


Reweighting At-Sat To Mitigate Group Score Differences, Andrew R. Dattel, Raymond E. King Jul 2006

Reweighting At-Sat To Mitigate Group Score Differences, Andrew R. Dattel, Raymond E. King

Publications

The Air Traffic Selection and Training (AT-SAT) test battery is the selection tool for applicants for Air Traffic Control Specialist (ATCS) positions within the Federal Aviation Administration (FAA) who have not previously been employed as an air traffic controller. AT-SAT is an aptitude test developed to predict the likelihood of successfully learning ATCS skills. Before operational use, however, concerns were raised about the low passing rate of incumbent (who are fully trained and certified) ATCS personnel (who participated in the initial research) and score differences between groups, which could result in adverse impact (possible unfair discrimination). To address these concerns, …


Performance Analysis Of Recoverable Flight Control Systems Subject To Neutron-Induced Upsets Using Hybrid Dynamical Models, Hong Zhang Jul 2006

Performance Analysis Of Recoverable Flight Control Systems Subject To Neutron-Induced Upsets Using Hybrid Dynamical Models, Hong Zhang

Electrical & Computer Engineering Theses & Dissertations

It has been observed that atmospheric neutrons can produce single-event upsets in digital flight control hardware. Potentially, they can reduce system performance and introduce a safety hazard. One experimental system-level approach investigated to help mitigate the effects of these upsets is NASA Langley's Recoverable Computer System. It employs rollback error recovery using dual-lock-step processors together with new fault tolerant architectures and communication subsystems.

In this dissertation, a class of stochastic hybrid dynamical models, which consists of a jump-linear system and a stochastic finite-state automaton, is used to describe the performance of a Boeing 737 aircraft system in closed-loop with a …


Human Error And Commercial Aviation Accidents: A Comprehensive, Fine-Grained Analysis Using Hfacs, Scott Shappell, Cristy Detwiler, Kali Holcomb, Carla Hackworth, Albert Boquet, Douglas Wiegmann Jul 2006

Human Error And Commercial Aviation Accidents: A Comprehensive, Fine-Grained Analysis Using Hfacs, Scott Shappell, Cristy Detwiler, Kali Holcomb, Carla Hackworth, Albert Boquet, Douglas Wiegmann

Publications

The Human Factors Analysis and Classification System (HFACS) is a theoretically based tool for investigating and analyzing human error associated with accidents and incidents. Previous research has shown that HFACS can be reliably used to identify general trends in the human factors associated with military and general aviation accidents. The aim of this study was to extend previous examinations of aviation accidents to include specific aircrew, environmental, supervisory, and organizational factors associated with 14 CFR Part 121 (Air Carrier) and 14 CFR Part 135 (Commuter) accidents using HFACS. The majority of causal factors were attributed to the aircrew and the …


An Operational Model For Mobile Sensor Cloud Management, Indrajeet Kalyankar Jul 2006

An Operational Model For Mobile Sensor Cloud Management, Indrajeet Kalyankar

Electrical & Computer Engineering Theses & Dissertations

Mobile sensors provide a safe, cost effective method for gathering information in hazardous environments. When the hazardous environment is either unexplored, such as the surface of Mars, or unanticipated, such as the result of chemical contamination, it is desirable for a system to gather information with a minimal amount of outside control (localization, decision control, etc.) and prepositioned sensors. If one takes a look at the number of the sensors deployed on a scale, at the lower end is the sole, multipurpose sensor unit. The upper end deals with hordes of inexpensive, expendable sensors. In the middle, a cluster of …


Sub-Banded Reconstructed Phase Spaces For Speech Recognition, Kevin M Indrebo, Richard J. Povinelli, Michael T. Johnson Jul 2006

Sub-Banded Reconstructed Phase Spaces For Speech Recognition, Kevin M Indrebo, Richard J. Povinelli, Michael T. Johnson

Electrical and Computer Engineering Faculty Research and Publications

A novel method combining filter banks and reconstructed phase spaces is proposed for the modeling and classification of speech. Reconstructed phase spaces, which are based on dynamical systems theory, have advantages over spectral-based analysis methods in that they can capture nonlinear or higher-order statistics. Recent work has shown that the natural measure of a reconstructed phase space can be used for modeling and classification of phonemes. In this work, sub-banding of speech, which has been examined for recognition of noise-corrupted speech, is studied in combination with phase space reconstruction. This sub-banding, which is motivated by empirical psychoacoustical studies, is shown …


Micron-Level Actuator For Thermal-Fluid Control In Microchannels, Nurhak Erbas Jul 2006

Micron-Level Actuator For Thermal-Fluid Control In Microchannels, Nurhak Erbas

Mechanical & Aerospace Engineering Theses & Dissertations

Effectiveness of an actuator is investigated for thermal-flow control in microchannels. First, simulations of a single actuator in a quiescent external medium are performed in order to study the parameters characterizing the synthetic jet flow from the actuator. For this purpose, a simplified, two-dimensional configuration is considered. The membrane motion is modeled in a realistic manner as a moving boundary in order to accurately compute the flow inside the actuator cavity. The geometric and actuation parameters of the actuator are investigated to define the effectiveness of the jet flow. The study is done initially at macro scales. Then, the flow …


High Performance Queueing And Scheduling In Support Of Multicasting In Input-Queued Switches, Weiying Zhu Jul 2006

High Performance Queueing And Scheduling In Support Of Multicasting In Input-Queued Switches, Weiying Zhu

Electrical & Computer Engineering Theses & Dissertations

Due to its mild requirement on the bandwidth of switching fabric and internal memory, the input-queued architecture is a practical solution for today's very high-speed switches. One of the notoriously difficult problems in the design of input-queued switches with very high link rates is the high performance queueing and scheduling of multicast traffic. This dissertation focuses on proposing novel solutions for this problem. The design challenge stems from the nature of multicast traffic, i.e., a multicast packet typically has multiple destinations. On the one hand, this nature makes queueing and scheduling of multicast traffic much more difficult than that of …