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2004

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Articles 1981 - 2010 of 2785

Full-Text Articles in Engineering

An Investigation Into Appliance Durability In The Presence Of Power System Disturbances, Steven R. Mcgovern Jan 2004

An Investigation Into Appliance Durability In The Presence Of Power System Disturbances, Steven R. Mcgovern

Masters

The increased trend towards miniaturisation and greater efficiency in electronic equipment has also resulted in increased susceptibility to power system disturbances. Such equipment has become less tolerant to supply transients and variations and as a result there has been an increase in consumer product damage complaints. Greater consumer awareness has seen power quality become a major issue for both the domestic user and the utility companies. Arising from these issues an approach from the Electricity Supply Board of Ireland was made to engage into an investigation of the effects of power quality disturbances at the low-voltage domestic level. On commencement …

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Enhancing Process Performance Through Automatic Control, Aidan O'Dwyer Jan 2004

Enhancing Process Performance Through Automatic Control, Aidan O'Dwyer

Conference papers

The proportional integral derivative (PID) controller is the most dominant form of automatic controller in industrial use today. With this technique, it is necessary to adjust the controller parameters according to the nature of the process. Thus, for effective control of a pasteurisation process, for example, specific values need to be chosen for the P, I and D parameters, which will be different for the values required to control, for example, a distillation column. This tailoring of controller to process is known as controller tuning.

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Cfd Analysis Of Unsteady Separated Transonic Oscillation Cascade Aerodynamics, Xuedong Zhou, J. Mitch Wolff Jan 2004

Cfd Analysis Of Unsteady Separated Transonic Oscillation Cascade Aerodynamics, Xuedong Zhou, J. Mitch Wolff

Mechanical and Materials Engineering Faculty Publications

With an improved algebraic mesh-deforming algorithm, STAR-CD, a commercial computational fluid dynamics (CFD) solver is employed for the numerical analysis of a transonic oscillating linear cascade of advanced design blades. The center blade oscillates 0.6-degrees about the middle cord. The numerical simulation is conducted for a frequency range from 200 Hz to 500 Hz. A hybrid grid, which utilizes a structured O-grid around the airfoil and an unstructured grid everywhere else is employed. The Spalart-Allmaras (S-A), one equation turbulence model, along with other two equation k-ε models, are also utilized for the steady state simulation. The S-A turbulence …

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Analysis Of Type And Severity Of Traffic Crashes At Signalized Intersections Using Tree-Based Regression And Ordered Probit Models, Joanne Marie Keller Jan 2004

Analysis Of Type And Severity Of Traffic Crashes At Signalized Intersections Using Tree-Based Regression And Ordered Probit Models, Joanne Marie Keller

Electronic Theses and Dissertations

Many studies have shown that intersections are among the most dangerous locations of a roadway network. Therefore, there is a need to understand the factors that contribute to traffic crashes at such locations. One approach is to model crash occurrences based on configuration, geometric characteristics and traffic. Instead of combining all variables and crash types to create a single statistical model, this analysis created several models that address the different factors that affect crashes, by type of collision as well as injury level, at signalized intersections. The first objective was to determine if there is a difference between important variables …

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Expression Morphing Between Different Orientations, Tao Fu Jan 2004

Expression Morphing Between Different Orientations, Tao Fu

Electronic Theses and Dissertations

How to generate new views based on given reference images has been an important and interesting topic in the area of image-based rendering. Two important algorithms that can be used are field morphing and view morphing. Field morphing, which is an algorithm of image morphing, generates new views based on two reference images which were taken at the same viewpoint. The most successful result of field morphing is morphing from one person's face to the other one's face. View morphing, which is an algorithm of view synthesis, generates in between views based on two reference views which were taken at …

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Investigation Of Ground Penetrating Radar For Detection Of Leaking Pipelines Under Roadway Pavements And Development Of Fiber-Wrapping Repair Technique, Pedro F. Suarez Jan 2004

Investigation Of Ground Penetrating Radar For Detection Of Leaking Pipelines Under Roadway Pavements And Development Of Fiber-Wrapping Repair Technique, Pedro F. Suarez

Electronic Theses and Dissertations

Nowadays, it has become a common practice to observe urban roadways undergo severe distress characterized by substantial depressions. In some cases, these pavement depressions are caused by leakages in the connecting joints of sewage pipelines laid beneath the roadway pavement. Manual inspection of pipe leakages has become costly and complex since sewage pipes with relative small diameters do not allow inspection from inside and digging may be required. On the other hand, pipes with large diameters, in which inspection can be made from pipe interior, inspector can not remain inside of the pipe for long periods of time because of …

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Planar Magnetics Design For Low-Voltage Dc-Dc Converters, Shangyang Xiao Jan 2004

Planar Magnetics Design For Low-Voltage Dc-Dc Converters, Shangyang Xiao

Electronic Theses and Dissertations

The objectives of this thesis are to design planar magnetic devices based on accurate electromagnetic analysis and miniaturize magnetics within desired low profile as well as small footprint. A novel methodology based on FEM simulation is proposed. By introducing Maxwell 2D simulator, optimal interleaving structures can be found to reduce AC losses that cannot otherwise be accounted for by conventional method. And 3D simulator is employed to make the results more realistic. Thus, high-efficiency high-power density magnetics is achieved.

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Modeling Of Membrane Solute Mass Transfer In Ro/Nf Membrane Systems, Yu Zhao Jan 2004

Modeling Of Membrane Solute Mass Transfer In Ro/Nf Membrane Systems, Yu Zhao

Electronic Theses and Dissertations

Five articles describing the impact of surface characteristics, and development of mass transfer models for diffusion controlled membrane applications are published in this dissertation. Article 1 (Chapter 3) describes the impact of membrane surface characteristics and NOM on membrane performance for varying pretreatment and membranes during a field study. Surface charge, hydrophobicity and roughness varied significantly among the four membranes used in the study. Membrane surface characteristics, NOM and SUVA measurements were used to describe mass transfer in a low pressure RO integrated membrane system. Inorganic and organic solute and water mass transfer coefficients were systematically investigated for dependence on …

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Biostability In Drinking Water Distribution Systems Study At Pilot-Scale, Michael Le Puil Jan 2004

Biostability In Drinking Water Distribution Systems Study At Pilot-Scale, Michael Le Puil

Electronic Theses and Dissertations

Biostability and related issues (e.g. nitrification) were investigated for 18 months in 18 pilot distribution systems, under various water quality scenarios. This study specifically investigated the impact of steady-state water changes on HPC levels in chlorinated and chloraminated distribution systems. Chlorination was more effective than chloramination in reducing HPC levels (1-2 log difference). There was a rapid increase in HPC corresponding to the change in steady-state water quality, which was observed in all PDS. Modeling effort demonstrated that HPC levels reached a maximum within five days after water quality change and return to initial level ten days after the change. …

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Effects Of The Soil Properties On The Maximum Dry Density Obtained Fro, Andres Arvelo Jan 2004

Effects Of The Soil Properties On The Maximum Dry Density Obtained Fro, Andres Arvelo

Electronic Theses and Dissertations

In the construction of highways, airports, and other structures, the compaction of soils is needed to improve its strength. In 1933 Proctor developed a laboratory compaction test to determine the maximum dry density of compacted soils, which can be used for specifications of field compaction. The Compaction of soils is influenced by many factors, the most common are the moisture content, the soil type and the applied compaction energy. The objective of this research is the analysis of the maximum dry density values based on the soil classification and characterization. The method of choice in the determination of the maximum …

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Predicting Air Quality Near Roadway Intersections Through The Applicat, Brian Kim Jan 2004

Predicting Air Quality Near Roadway Intersections Through The Applicat, Brian Kim

Electronic Theses and Dissertations

With substantial health and economic impacts attached to many highway-related projects, it has become imperative that the models used to assess air quality be as accurate as possible. The United States (US) Environmental Protection Agency (EPA) currently promulgates the use of CAL3QHC to model concentrations of carbon monoxide (CO) near roadway intersections. This model uses steady-state and macroscopic methods to model the physical phenomena (e.g., emission rates, atmospheric dispersion, etc.) occurring at intersections. These methods are not straightforward and unintuitive for the users. Therefore, this project investigated the possibility of developing a model that is theoretically more realistic and flexible …

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Performance Analysis Of Low-Power, Short-Range Wireless Transceivers, Usha Neupane Jan 2004

Performance Analysis Of Low-Power, Short-Range Wireless Transceivers, Usha Neupane

Electronic Theses and Dissertations

To address the various emerging standards like BluetoothTM, Home RF, Wi-fiTM (IEEE 802.11), ZigBeeTM etc., in the field of wireless communications, different transceivers have been designed to operate at various frequencies such as 450 MHz, 902-920 MHz, 2.4 GHz, all part of designated ISM band. Though, the wireless systems have become more reliable, compact and easy to develop than before, a detailed performance analysis and characterization of the devices should be done. This report details the performance analysis and characterization of a popular binary FSK transceiver TRF6901 from Texas Instruments. The performance analysis of the device is done with respect …

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Modeling Crash Frequencies At Signalized Intersections In Central Flor, Smitha Kowdla Jan 2004

Modeling Crash Frequencies At Signalized Intersections In Central Flor, Smitha Kowdla

Electronic Theses and Dissertations

A high percentage of highway crashes in the United States occur at intersections. These crashes result in property damage, lost productivity, injury, and even death. Identifying intersections associated with high crash rate is very important to minimize future crashes. The purpose of this study is to develop efficient means to evaluate intersections, which may require safety improvements. The area covered by the analysis in this thesis includes Orange and Seminole Counties and the City of Orlando. The aforementioned counties and city thus represent Central Florida. Each County/City provided data that consisted of signalized intersection drawings that were either in the …

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Effects Of Deposition Temperature And Post Deposition Annealing On The Electrical Properties Of Barium Strontium Titanate Thin Film For Embedded Capacitor Applications, Ranganathan, Ravip Peelamedu Jan 2004

Effects Of Deposition Temperature And Post Deposition Annealing On The Electrical Properties Of Barium Strontium Titanate Thin Film For Embedded Capacitor Applications, Ranganathan, Ravip Peelamedu

Electronic Theses and Dissertations

A higher degree of system level integration can be achieved by integrating the passive components into semiconductor devices, which seem to be an enabling technology for portable communication and modern electronic devices. Greater functionality, higher performance and increase in reliability can be achieved by miniaturizing and reducing the number of components in integrated circuits. The functional potential of small electronic devices can be enormously increased by implementing the embedded capacitors, resistors and inductors. This would free up surface real estate allowing either a smaller footprint or more silicon devices to be placed on the same sized substrate. This thesis focuses …

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Performance Of Interface Elements In The Finite Element Method, Kairas Rabadi Jan 2004

Performance Of Interface Elements In The Finite Element Method, Kairas Rabadi

Electronic Theses and Dissertations

The objective of this research is to assess the performance of interface elements in the finite element method. Interface elements are implemented in the finite element codes such as MSC.NASTRAN, which is used in this study. Interface elements in MSC.NASTRAN provide a tool to transition between a shell-meshed region to another shell-meshed region as well as from a shell-meshed region to a solid-meshed region. Often, in practice shell elements are layered on shell elements or on solid elements without the use of interface elements. This is potentially inaccurate arising in mismatched degrees of freedom. In the case of a shell-to-shell …

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Autonomous Robotic Automation Systemwith Vision Feedback, Jeffery Rosino Jan 2004

Autonomous Robotic Automation Systemwith Vision Feedback, Jeffery Rosino

Electronic Theses and Dissertations

In this thesis, a full design, development and application of an autonomous robotic automation system using vision feedback is performed. To realize this system, a cylindrical manipulator configuration is implemented, using a personal computer (PC) based PID controller from National Instruments. Full autonomous control will be achieved via a programmable human machine interface (HMI) developed on a PC using Borland C++ Builder. The vision feedback position control is accomplished using an ordinary "off-the-shelf" web camera. The manuscript is organized as follows; After Chapter 1, an introduction to automation history and its role in the manufacturing industry, Chapter 2 discusses and …

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Failure Mode Identifications Of Rc Beams Externally Strengthened With, Chris O'Riordan-Adjah Jan 2004

Failure Mode Identifications Of Rc Beams Externally Strengthened With, Chris O'Riordan-Adjah

Electronic Theses and Dissertations

The application of carbon reinforced-fiber polymers (CFRP) to structures is a new development that is still under intense research. However, the rehabilitation or retrofit of damage reinforced concrete members by the external bonding of CFRP is becoming increasingly popular in the construction industry. The objective of the tests presented in this thesis is to study different CFRP designs on the reinforced concrete beams and compare their failure modes. The main goal is to determine the CFRP design on the reinforced concrete beams that result in a progressive and gradual failure mode with enough warning before final failure. Different CFRP designs …

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Decision Support Model For Construction Crew Reassignments, Angela M. Sist Jan 2004

Decision Support Model For Construction Crew Reassignments, Angela M. Sist

Electronic Theses and Dissertations

The reassignment of crews on a construction project in response to changes occurs on a frequent basis. The factors that affect the crew reassignment decision can be myriad and most are not known with certainty. This research addresses the need for a decision support model to assist construction managers with the crew reassignment problem. The model design makes use of certainty factors in a decision tree structure. The research helped to determine the elements in the decision tree, the appropriate combination rules to use with the certainty factors, and the method for combining the certainty factors and costs to develop …

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Microstructural Analysis Of Varistors Prepared From Nanosize Zno, Suresh Pillai, Declan Mccormack, John Kelly, Ramesh Raghavendra Jan 2004

Microstructural Analysis Of Varistors Prepared From Nanosize Zno, Suresh Pillai, Declan Mccormack, John Kelly, Ramesh Raghavendra

Articles

No abstract provided.

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Microwave Induced Preparation Of A-Axis Oriented Double-Ended Needle-Shaped Zno Microparticles, Suresh Pillai, John Kelly, Graeme Watson, Deirdre Ledwith Jan 2004

Microwave Induced Preparation Of A-Axis Oriented Double-Ended Needle-Shaped Zno Microparticles, Suresh Pillai, John Kelly, Graeme Watson, Deirdre Ledwith

Articles

Microwave irradiation of solutions of Zn(NO3)2 and urea provides a straightforward route to a-axis oriented crystals of needle-like morphology.



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Low-Temperature Crystallization Of Sol–Gel Processed Pb0.5ba0.5tio3: Powders And Oriented Thin Films, Suresh Pillai, Stacey Boland, Sossina Haile Jan 2004

Low-Temperature Crystallization Of Sol–Gel Processed Pb0.5ba0.5tio3: Powders And Oriented Thin Films, Suresh Pillai, Stacey Boland, Sossina Haile

Articles

A novel sol– gel process suitable for depositing thin-film lead
barium titanate has been developed. X-ray diffraction analysis
showed perovskite phase crystallization to occur at a temperature
as low as 400°C with single-phase Pb0.5Ba0.5TiO3 (PBT)
resulting at a temperature as low as 500°C. Small concentrations
of barium carbonate were evident by X-ray diffraction at
400°C, and indications of minor, carbonate-containing phases
were evident by FTIR at 600°C. Deposition of the sol by spin
coating on single-crystal and thin-film MgO on silicon resulted
in highly oriented PBT films after calcination at 600°C. Mixed
(100)/(001) films were obtained on single-crystal MgO,
whereas …

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Impulse, Dave Graves, Kyle Johnson Jan 2004

Impulse, Dave Graves, Kyle Johnson

Impulse (Jerome J. Lohr College of Engineering Publication)

Features:
[Page] 2 SDSU engineers restore Solberg Hall to active duty: From donors to the project manager, this effort was the project of alumni.
[Page] 4 Unique funding spawns new Solberg Hall: At $1, Solberg was the best purchase the State ever made.
[Page] 6 Back from Iraq: Guard members tell their story about the restoration of Iraq.
[Page] 8 Inquisitive nature leads Barnett to 'quality' career: Andy Barnett was living in a monastery when he decided to be an engineer
[Page] 10 Mobile classroom brings science to students: Retired teachers drive the truck and an SDSU instructor steers the …

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Summary Report: Strength Of Single L-Headers, Roger A. Laboube Jan 2004

Summary Report: Strength Of Single L-Headers, Roger A. Laboube

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

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Corrosion Of Galvanized Fasteners Used In Cold-Formed Steel Framing, American Iron And Steel Institute Jan 2004

Corrosion Of Galvanized Fasteners Used In Cold-Formed Steel Framing, American Iron And Steel Institute

CCFSS Library (1939 - present)

This research program investigated the potential for corrosion of galvanized fasteners used in cold-formed steel framing by exposing test samples to a variety of environmental conditions frequently found in Hawaii and elsewhere. The results of this research will aid in the evaluation of galvanized fasteners in various exposure conditions. Five field enclosures were constructed on the island of Oahu at coastal locations on both windward and leeward shores, and in the interior of the island. Each field enclosure represented various aspects of typical cold-formed steel construction and was equipped with a complete weather station. This report details the design, construction …

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Tradition Versus Technology: Careers Fairs In The 21st Century, Christiane Brennan, Margaret Daly, Eileen Fitzpatrick, Edward Sweeney Jan 2004

Tradition Versus Technology: Careers Fairs In The 21st Century, Christiane Brennan, Margaret Daly, Eileen Fitzpatrick, Edward Sweeney

Articles

The traditional methods of graduate recruitment do not adequately meet the needs of the changing profile of students and graduates. As industry becomes internationalized, the needs of employers are also changing. Graduate recruitment is in response to short term needs and varying levels of experience are required. A case study method was used in Technological University Dublin to evaluate effectiveness of a virtual careers fair in providing greater access to job opportunities for students and graduates. Access by employers to potential employees was also measured. Findings showed that while access improved, other issues requiring attention emerged.

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Policosanol Contents And Composition Of Grain Sorghum Kernels And Dried Distillers Grains, Keum T. Hwang, Curtis L. Weller, Susan L. Cuppett, Milford Hanna Jan 2004

Policosanol Contents And Composition Of Grain Sorghum Kernels And Dried Distillers Grains, Keum T. Hwang, Curtis L. Weller, Susan L. Cuppett, Milford Hanna

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Grain sorghum can be a major source of policosanols, long-chained alcohols, that have beneficial physiological activities. Sorghum dried distillers grains (DDG), a by-product of ethanol production from grain sorghum. contain a large amount of policosanols. Content and composition of policosanols in long-chained lipids extracted from grain sorghum kernels and DDG were determined. Long-chained lipids were extracted using hot hexane or hot ethanol. The major components of the long-chained lipids extracted from grain sorghum kernels. as determined using HPLC were policosanols (37-44%), aldehydes (44-55%), and acids (4-5%). Long-chained lipids from DDG contained 52% policosanols, 23% aldehydes. 6.4% acids. and l7% wax …

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Improving Heating Uniformity Of Fresh Fruit In Radio Frequency Treatments For Pest Control, Sohan Birla, Shaojin Wang, Juming Tang, Guy Hallman Jan 2004

Improving Heating Uniformity Of Fresh Fruit In Radio Frequency Treatments For Pest Control, Sohan Birla, Shaojin Wang, Juming Tang, Guy Hallman

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Non-uniform heating of fresh fruit caused by variations in radio frequency (RF) fields is a major obstacle in developing postharvest insect control treatments based on RF energy. A fruit mover was developed to evaluate possibilities to improve RF heating uniformity of large fruit, such as oranges and apples, in a 12 kW batch type RF system. This fruit mover provided a means to rotate and move fruit in water when subjected to RF heating. Parameters for moving and rotating fruit in the mover were selected based on consideration of vortex formation, foaming, damage to the fruit, and volume occupied by …

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Quantum Mechanical Analysis Of Channel Access Geometry And Series Resistance In Nanoscale Transistors, R. Venugopal, S. Goasguen, S. Datta, M. S. Lundstrom Jan 2004

Quantum Mechanical Analysis Of Channel Access Geometry And Series Resistance In Nanoscale Transistors, R. Venugopal, S. Goasguen, S. Datta, M. S. Lundstrom

Other Nanotechnology Publications

We apply a two-dimensional quantum mechanical simulation scheme to study the effect of channel access geometries on device performance. This simulation scheme solves the nonequilibrium Green’s function equations self-consistently with Poisson’s equation and treats the effect of scattering using a simple approximation inspired by Bu ̈ttiker. It is based on an expansion of the device Hamiltonian in coupled mode space. Simulation results are used to highlight quantum effects and discuss the importance of scattering when examining the transport properties of nanoscale transistors with differing channel access geometries. Additionally, an efficient domain decomposition scheme for evaluating the performance of nanoscale transistors …

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Development & Validation Of The Acoustic Analogy Code For Jet Noise Predictions, Leonardo A. Bueno-Benitez Jan 2004

Development & Validation Of The Acoustic Analogy Code For Jet Noise Predictions, Leonardo A. Bueno-Benitez

Master's Theses - Daytona Beach

In this thesis, the numerical code for predicting the far-field sound radiated from a localized sound source is developed based on Lighthill's acoustic analogy theory. The acoustic analogy equation allows calculating the sound intensity in terms of the integral over the volume with distributed Lighthill tensor of unsteady flow fluctuations. A FORTRAN code is written to perform the integration using Simpson's numeric technique. The procedure for validating the code against the test case for the sound source in the form of a Gaussian pulse is examined. Future application of the code to predict acoustic radiation from turbulent jets is briefly …

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An Analysis Of The Effects That Several Design Variables Have On The Accuracy And Precision Of Glass’ Delta And Hedges’ G, Joshua N. Dryer Jan 2004

An Analysis Of The Effects That Several Design Variables Have On The Accuracy And Precision Of Glass’ Delta And Hedges’ G, Joshua N. Dryer

Master's Theses - Daytona Beach

Effect size is the standardized effect that some treatment has on a sample of a population. In particular, Hedges' g and Glass delta are mean difference effect size estimators that are used to compute the effect sizes found in an experimental situation. A confidence interval is an interval placed around a point estimate that indicates the precision with which the point estimate can be made. This paper provides an explanation of the concept of effect size estimation and confidence interval calculation, the different methods that can be used to calculate effect sizes and confidence intervals, and applies these methods in …

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