Radio frequency identification (RFID) is used to identify, track, and manage tagged animate or inanimate objects automatically using wireless communication technology. RFID is similar to existing barcode identification, but it has additional features. RFID has the capability of scanning multiple objects at the same time. This improves productivity by reducing the time taken to identify objects. RFID has the capability to read through opaque material without requiring line of sight, thus saving time in processing that would otherwise require upwardfacing objects. RFID is extremely appropriate for applications that require tags to be read at large distances. RFID readers and tags come in various sizes and forms, thus permitting this type of technology to be used in a broad variety of situations. Some tags are blast-proof, some tags are the size of lunch boxes, and some are smaller than a grain of rice. Also, RFID tags can be reprogrammable, thus reducing cost. As RFID technology continues to grow rapidly, different issues and challenges are presented. A serious concern faced by RFID technology is the collisions that occur during communication. This is considered one of the immense challenges in RFID development because collisions limit system performance significantly. Collisions bring extra delay, a waste of bandwidth, and extra energy consumption to the interrogation process of RFID. Delays that arise due to collisions in RFID systems create significant issues and challenges to applications that require high inventory speed. Therefore, RFID system designers and researchers need to simulate these different environments before deployment to correctly identify various factors, such as the number of RFID readers needed, where to place these readers, etc. The simulator developed in this research is called the RFID Simulator. It was developed completely from scratch to evaluate the performance of Slotted Aloha and EPCglobal Class-1 Generation-2 protocols for RFID systems. The RFID Simulator was designed to replicate a reallife RFID environment. It can be used to imitate hardware and has the capability to calculate the delay to any number of RFID tags, which is not possible with real-life RFID systems. As a result, the performance of RFID systems can be improved significantly. The integrity of the simulator was verified by comparing its results with mathematical analysis and experimental results. The RFID Simulator is a complete, all-in-one package, designed with the ability to be extended to a commercial RFID simulator, which will help immensely in the future development of RFID. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Electrical Engineering and Computer Science.

In the process control industry, majority of control loops are based on Proportional-Integral-Derivative (PID) controllers. The basic structure of the PID controllers makes it easy to regulate the process output. Design methods leading to an optimal and effective operation of the PID controllers are economically vital for process industries. Robust control has been a recent addition to the field of control engineering that primarily deals with obtaining system robustness in presences of uncertainties. In this thesis, a graphical design method for obtaining the entire range of PID controller gains that robustly stabilize a system in the presence of time delays and additive uncertainty is introduced. This design method primarily depends on the frequency response of the system, which can serve to reduce the complexities involved in plant modeling. The fact that time-delays and parametric uncertainties are almost always present in real time processes makes our controller design method very vital for process control. We have applied our design method to a DC motor model with a communication delay and a single area non-reheat steam generation unit. The results were satisfactory and robust stability was achieved for the perturbed plants. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Electrical Engineering and Computer Science.

Aircraft in-flight icing is a major safety issue for civil aviation, having already caused hundreds of accidents and incidents related to aerodynamic degradation due to post takeoff ice accretion. Airplane makers have to protect the airframe critical surfaces against ice build up in order to ensure continued safe flight. Ice protection is typically performed by mechanical, chemical, or thermal systems. One of the most traditional and still used techniques is the one known as hot-air anti-icing, which heats the interior of the affected surfaces with an array of small hot-air jets generated by a piccolo tube. In some cases, the thermal energy provided by hot-air ice protection systems is high enough to fully evaporate the impinging supercooled droplets (fully evaporative systems), while in other cases, it is only sufficient to maintain most of the protected region free of ice (running wet systems). In the latter case, runback ice formations are often observed downstream of the wing leading edge depending on hot-air, icing, and flight conditions. The design process of hot-air anti-icing systems is traditionally based on icing wind tunnel experiments, which can be very costly. The experimental effort can be significantly reduced with the use of accurate three-dimensional computational fluid dynamic (CFD) simulation tools. Nevertheless, such type of simulation requires extensive CPU time for exploring all the design variables. This thesis deals with the development of an efficient hot-air anti-icing system simulation tool that can reduce the computational time to identify the critical design parameters by at least two orders of magnitude, as compared to 3-d CFD tools, therefore narrowing down the use of more sophisticated tools to just a small subset of the entire design space. The hot-air anti-icing simulation tool is based on a combination of available CFD software and a thermodynamic model developed in the present work. The computation of the external flow properties is performed with FLUENT (in a 2-d domain) by assuming an isothermal condition to the airfoil external wall. The internal skin heat transfer is computed with the use of local Nusselt number correlations developed through calibrations with CFD data. The internal and external flow properties on the airfoil skin are provided as inputs to a steady state thermodynamic model, which is composed of a 2-d heat diffusion model and a 1-d uniform film model for the runback water flow. The performance of the numerical tool was tested against 3-d CFD simulation and experimental data obtained for a wing equipped with a representative piccolo tube anti-icing system. The results demonstrate that the simplifications do not affect significantly the fidelity of the predictions, suggesting that the numerical tool can be used to support parametric and optimization studies during the development of hot-air anti-icing systems. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Aerospace Engineering.

The shedding of ice accreted on aircraft surfaces poses a serious threat to flight safety as it can cause severe damage to downstream aircraft components such as aft-mounted engines. While there is strong need for ice shedding simulation tools to support aircraft icing analysis and certification, currently available ice shedding analysis methods may not predict ice fragment trajectory accurately due to the inability to simulate the random nature of ice shedding events and the lack of experimental aerodynamic data for ice fragments. In addition, most of the simulation tools have not been validated with experimental trajectory data. Both experimental and numerical investigations of shed ice trajectory were conducted as part of the continuing development of an ice trajectory simulation tool at Wichita State University. The research discussed in this thesis involved wind tunnel experiments conducted to obtain experimental aerodynamic coefficients for simulated ice fragments, numerical ice trajectory analyses, Monte Carlo simulations to evaluate the risk of ice fragment impact on critical aircraft components, and trajectory experiments performed to validate the ice trajectory simulation tool. Wind tunnel experiments were performed in the WSU 7-ft x 10-ft wind tunnel facility to obtain an aerodynamic database of force and moment coefficients for a 12-inch square flat plate with 0.4-inch thickness, a 10-inch diameter disk with 1-inch thickness and a 18-inch span glaze ice fragment with symmetric horns computed with the LEWICE ice accretion code. The experiments were conducted at airspeed of 160 mph with varying Euler angles (yaw, pitch and roll). The aerodynamic coefficients of the three fragments tested demonstrated considerable sensitivity to fragment shape and orientation. The experimental data were incorporated into the WSU trajectory analysis code developed. The ice shedding analyses were conducted with two simulated ice fragments for a business jet aircraft using the WSU trajectory code. The two simulated ice fragments include a disk and a glaze ice fragment with symmetric horns released from the aircraft nose and from the antenna on the top of the fuselage, respectively. Monte Carlo simulations were performed to compute probability maps of trajectory footprints at the engine inlet plane. The analysis demonstrated the effect of the shed location, initial fragment orientation and aircraft angle of attack on ice fragment trajectories. The results for Monte Carlo simulations performed with the disk fragment showed that the fragment would have less than a 0.15% chance of impacting the engine. For the glaze ice fragment, it was found that the probability of a collision between the fragment and the engine was as high as 24.2%, depending on the aircraft’s pitch and yaw angles. Next, an experimental methodology was developed to obtain the trajectories of simulated ice fragments released in a tunnel airstream for the validation of the ice fragment trajectory code. The tested fragments were a 6-inch square flat plate with 0.4-inch thickness, a rectangular flat plate measuring 12- inch long by 6-inch wide by 0.4-inch thick, a 12-inch span single horn glaze ice fragment and a 12-inch span double horn symmetric glaze ice fragment. Experiments were performed at airspeed of 160 mph in the WSU 7-ft x 10-ft wind tunnel facility. High-speed video cameras were employed to record the fragment’s trajectories at 500 to 1,000 frames per second. The coordinates of a fragment’s trajectories were determined from high speed images with the help of gridded vinyl sheets attached to one of the wind tunnel side-walls and to the ceiling. The fragment trajectories showed considerable sensitivity to the ice fragment shapes and their initial pitch angles at the moment of release. The flat plates with initial pitch angle of 0° experienced considerable rotation as they moved downstream, while the flat plate with initial pitch angle of 90° traveled downstream in a nearly straight path without rotation. Two cases of the single horn glaze ice fragment were sensitive to initial orientation and exhibited oscillatory rotations with respect to their spanwise axis. Two cases of the double horn symmetric glaze ice fragment resulted in similar trajectories, however experienced considerably different speed. Finally, the experimental trajectories were compared with analytical trajectories computed with the WSU trajectory code. Good agreement was demonstrated between the experimental and computed trajectories in most cases. However, the analytical results for the flat plate cases with significant rotations were more than 10% different compared to the experimental data due to the effect of the plate large rotation speed on the aerodynamic forces and moments acting on the plates. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Aerospace Engineering.

The current study was undertaken with an intention to verify and extend the boundaries of the work produced by Xia & Murthy [24] and Vargas [23] on natural convective flows inside a cubical enclosure to observe the transition to turbulence. Their primary focus was to better understand the flows inside a cubical enclosure at higher Rayleigh numbers (Ra) with the help of Direct Numerical Simulation (DNS). This helps in understanding the mixing process that takes place inside the center wing tank of a commercial airplane. The motivation behind the current study was to stretch the limits of the work done by Vargas by adapting central differencing scheme (CDS) of discretization at three different grid sizes of 50^3, 75^3 and 90^3 with DNS. In order to achieve this task, we used the code developed by FLUENT for finite volume method. The cavity was created and meshed in GAMBIT with the bottom wall heated, top wall cooled and the side walls maintained adiabatic. Then, the Ra is varied between 2 x 10^4 and 10^9 maintaining the Prandtl number (Pr) to be constant at 2.5. Initially, the results were verified with those of Vargas and Xia & Murthy and similar observations were made with steady convective flows at Ra = 2 x 10^4, 10^5 and 2 x 10^5. Periodic flows were captured at the critical Ra = 4.07 x 10^5 beyond which flows exhibited the chaotic nature until Ra = 10^9. The work was then carried forward with the idea of employing the CDS of discretization at higher Ra up to 10^9 along with a finer grid density of 90^3 control volumes. The power spectrum slopes have been compared with the Kolmogorov’s -5/3 rule for turbulent flows to observe the transition to turbulence. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Mechanical Engineering.

In a structure, a joint is considered as the weakest part, and it should not get separated when subjected to loading, so that an unstable collapse of structure can be avoided. It is important to investigate the failure in joint before it is used in a structure. Failure of a joint depends on various factors such as the geometry of joint configuration, sheet strength that are joined, rivet material used, cracks developed during joining, and many other. Self-Piercing riveting process is a new technology for joining sheet metals in automobile and aircraft industries. This process has many advantages over conventional joining processes. In this thesis, the failure of a self-piercing riveted joint is investigated. Failure of three different riveted configurations under 35m/s and 60m/s velocities were predicted using the general purpose non-linear finite element software LS-DYNA. This research is divided into three stages of work. In the first stage, a 2D simulation of riveting process is carried out over two Aluminum sheets. An r-adaptive methodology is utilized to acquire a higher accuracy of results and to avoid high element distortion. A parametrical study is then conducted to study the effect of rivet penetration velocity and adaptive mesh size varies the quality of the joint. In the second stage of work, a spring back analysis of joint is conducted to study the deformations of work piece after the riveting process. In the third stage, a Peel specimen, a U-shaped single riveted connection, and a U-shaped double riveted connection were investigated for failure under 35 m/s and 60 m/s velocities in both shear and tension testing conditions. Three different loading conditions were used for testing. The results from this study will show how process parameters can influence the quality of riveted joint, amount of deformations that occur in the work piece after the removal of rigid bodies, and failure load of SPR joint in different configurations. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Mechanical Engineering.

Students experiencing mental fatigue while pursuing high levels of achievement may refocus attention, gain cognitive benefits, and increase achievement by taking breaks from class work. In this quantitative study, two types of breaks, sedentary versus structured movement, were compared to determine whether one demonstrated greater efficacy for increasing the algebra achievement of gifted fifth graders. Daily ten-minute breaks were taken during math class across a six-week period. When algebra achievement data associated with structured movement breaks were compared to the data associated with sedentary breaks, results indicated that nine out of eleven students made their greatest individual growth during the structured movement break treatment. / Thesis (M.Ed.)--Wichita State University, College of Education, Dept. of Curriculum & Instruction.

This study explored the relationship between epistemological beliefs, ways of knowing, parenting styles, and how one reacts to a child with Asperger Syndrome acting out in public. The purpose was to determine whether or not epistemological beliefs, ways of knowing, and parenting style could be used to predict how an individual would respond in such a situation. The epistemological beliefs looked at were certain knowledge and omniscient authority. Ways of knowing were classified as connected knowing and separate knowing. Parenting styles were categorized as authoritarian, authoritative, and permissive. Two hundred and nine college students between the ages of 19 and 55 participated in the study, coming from both a mediumsized metropolitan university in the Midwest and a medium-sized university on the west coast. The participants completed the Epistemic Beliefs Inventory questions pertaining to certain knowledge and omniscient authority (Schraw, Bendixen, & Dunkle, 2002), the Attitudes Toward Thinking and Learning Survey (Galotti, Clinchy, Ainsworth, Lavin, & Mansfield, 1999), the Parental Authority Questionnaire – Revised (Reitman, Rhode, Hupp, & Altobello, 2002), demographic questions, and responded to a scenario involving a child with Asperger Syndrome. People who gave appropriate advice had higher scores in connected knowing than people who gave inappropriate advice, suggesting that higher levels of connected knowing lead to more appropriate reactions to such situations. An ancillary analysis revealed that authoritative parenting, separate knowing, and certain knowledge are related to connected knowing. Future research is suggested to explore those relationships. / Thesis (M.Ed.)--Wichita State University, College of Education, Dept. Counseling, Educational and School Psychology.

A Mobile Ad hoc Network (MANET) is a collection of mobile nodes that operate without any backbone infrastructure support. Implementation of MANETS is very useful in certain military applications and during emergency situations such as earth quakes and re accidents. In MANETS, routing decisions are governed by the operating routing protocol. Mobility is one of the most important factors to be considered in developing such routing protocols. The e ect of mobility on a network is quanti ed in terms of link and route duration times. Therefore, understanding mobility and its e ect on path duration will de nitely help in coming up with a better routing algorithm. In this thesis, we discuss the importance of mobility and its impact on a network. Also, we tried to come up with an enhanced version of the mathematical model for the path duration estimate from an existing model. One application of the path duration estimate is to select a route with maximum expiry time unlike most of the routing algorithms which choose a path based on shortest path. First, we estimate route expiry time with a single relay node between the source and the destination. With this simple scenario, we analyze how long it takes for a relay node to come out of the transmission range of the source node. Then, we generalize the analysis for h number of hops used to reach destination. Also, the e ect on path duration due to parameters such as transmission range, node mobility, relative velocity, and number of hops in the route is studied. Simulations are performed in MATLAB and the signi cance of the proposed model is discussed with an analysis of the results obtained. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Electrical Engineering and Computer Science

The research and writing of this thesis began with strong interest in the compelling area of ecofeminist theory (specifically, its successful application to literary theory) and the realization that Thomas Hardy’s tragic fiction seemed to echo many of the assertions made by contemporary ecofeminist critics. A close reading of Hardy’s last four tragic novels revealed seemingly limitless approaches within an ecofeminist reading of Hardy’s work, so a reading from a perspective viewing the author as ecofeminist developed. In the interests of accuracy and tracing social causes of Victorian era events that contributed to Hardy’s ecofeminism, the research necessary was diverse and interconnected in many ways. Industrial Revolution, urbanization, changes in social norms, and tension caused by gendered roles shifting all become apparent in a study of Victorian England’s social atmosphere, and all these events occur during a vast change to the country’s natural environment and mankind’s necessary interactions with nature. The web of interconnections required by virtually all cultural theory becomes clearly visible, as did Thomas Hardy’s cultural experiences and personal beliefs. Indeed, Hardy was concerned with the plights of women, nature, and other non-dominant portions of his world; just as ecofeminism asserts, Hardy portrays a world in which oppression by a male-dominated society is at the root of countless problems and inequities. / Thesis (M.A.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of English.