In this thesis, the performance of a decentralized system was analyzed based upon the design of the controller, either a reduced-order model or a full-order model. The singular perturbation technique was used to obtain the reduced-order model of a decentralized system. Then this model was used to design a controller for state feedback. Since this controller was the reduced-order model of the system, it was implemented based on the full-order model by padding zeroes. Thus, the controller was an approximation. Hence, a performance analysis was conducted to verify the near approximation of the design using the singular perturbation technique. To check the sensitivity of the design, the performance of the system using the controller designed on the full-order system was compared with the performance of the system using the controller designed on the reduced-order model. A comparison of the results showed that the effectiveness of the reduced-order model design can be verified and checked as to whether it is giving the required approximate results for a lower-cost controller design. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Electrical Engineering and Computer Science.

As an aircraft wing approaches the ground, within a chord-length distance, it experiences an increase in lift and a decrease in drag. This is known as ―ground effect.‖ Furthermore, a Gurney flap positioned perpendicular to an airfoil’s trailing edge (with a 1% to 5% chord length) will also increase the lift. This thesis addresses the following question: Are the combined effects of these phenomena additive to any significant degree? Specifically, can the addition of a Gurney flap to an airfoil during ground effect increase the lift substantially, and are there any tradeoffs to be considered? Notable performance improvements could impact wing-in-ground-effect (WIG) aircraft. Such vehicles fly close to the ground (in ground effect [IGE]) to produce more lift than the wing would normally (out of ground effect [OGE]). WIG aircraft can be a small one-person aircraft or large transport aircraft like the Russian Ekranoplans. Currently, because these aircraft fly only IGE, they are literally inches off the surface of the ground. Further Gurney flap research could be beneficial for improving similar future aircraft. If the effects are additive, then WIG aircraft could be constructed to fly more safely at greater heights. This thesis was completed in three phases. First, a literature review was conducted to better understand ground effect and Gurney flaps. Interestingly, only one article was discovered that discussed combining both phenomena (for race car down-force enhancement applications). Second, basic and available two-dimensional computer codes were evaluated as potential tools for analysis and design. Only one was capable of analyzing an airfoil with a Gurney flap in ground effect. Third, v experiments were conducted in the low-speed wind tunnel at Wichita State University to directly evaluate the effect of a Gurney flap on airfoil performance in ground effect. Based on the results of this investigation, the following can be stated: JavaFoil, a computer program available online, reasonably models airfoil performance trends with Gurney flaps while in ground effect. Experiments indicate that the addition of a Gurney flap to an S7055 airfoil improves its lift, both in and out of ground effect (by up to 68%). Interestingly, the effects vary with angle of attack and are most pronounced at small values. But there are also tradeoffs to consider. Specifically, an increase in drag (approximately 48%) and a more nose-down pitching moment (about 85%) accompanies the lift improvement for the S7055 airfoil used for testing. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Aerospace Engineering.

This thesis compared the performance of a blind relay communication system with that of a non-blind relay communication system. For a blind system, a differential space-time block code (DSTBC) or a blind Viterbi detection were used, and for a non-blind system, a space-time block code (STBC) was used. Also, this thesis took another blind detection mechanism, the Zhang’s code, and compared its performance with that of the blind Viterbi detection under a Jakes’ fading environment. It was found that the case of a relay closer to the destination shows better performance than the other case of a relay closer to the destination. It was also observed that the blind Viterbi decoder shows better performance than the Zhang’s code under the Jakes’ fading environment. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Electrical Engineering and Computer Science.

This study is a qualitative examination of the definitions, beliefs, practices and the importance of consent within the Leather and Bondage, Domination, Sadomasochism (BDSM) communities using the experiences of those who identify as members of those communities. Through interviews with fifteen self-identified practitioners of BDSM/Leather, the research attempts to define consent, identify the importance of consent, and how consent is practiced within those lifestyles. It also seeks to address some of the commonly held misconceptions concerning the BDSM and Leather communities held by those outside the communities. The research attempts to establish how members of the communities define and practice consent in both their sexual and everyday lives. The standard definition of consent given was an "informed agreement between persons to act in an activity which is mutually beneficial for everybody involved." (I1) Additional elements to the basic definition included the necessity of a sound mind (I2 & I3), that the agreement is made willingly, free from coercion and outside influence - either from another person or from mind altering substances (I1,I2, I3, I6, I14), and that consent must be given by both the dominant and submissive partners. Also, consent for the Leather and BDSM practitioners interviewed included an understanding by all parties about what was expected, what the parties were and were not willing to do during the course of the interaction (the scene), and where consent stopped. At its most basic level the idea of consent was stated as "the ability to say yes." (I13) / Thesis (M.A.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Liberal Studies

Current wireless MAC protocols are designed to provide an equal share of throughput to all nodes in the network. However, the presence of misbehaving nodes (selfish nodes that deviate from standard protocol behavior in order to obtain higher bandwidth) poses severe threats to the fairness aspects of MAC protocols. In this thesis, investigation of various types of MAC layer misbehaviors is done, and their effectiveness is evaluated in terms of their impact on important performance aspects including throughput, and fairness to other users. Observations obtained from the simulation of misbehaviors show that the effects of misbehavior are prominent only when the network traffic is sufficiently large and the extent of misbehavior is reasonably aggressive. In addition, it is also observed that the performance gains achieved using misbehavior exhibit diminishing returns with respect to its aggressiveness, for all types of misbehaviors considered. Crucial common characteristics among such misbehaviors are identified, and these learnings are used to design an effective measure to react towards such misbehaviors. Employing two of the most effective misbehaviors, it is shown that collective aggressiveness of non-selfish nodes is a possible strategy to react towards selfish misbehavior. Particularly, a dynamic collective aggressive reaction approach is demonstrated to ensure fairness in the network, however at the expense of overall network throughput degradation. In addition, the proposed adaptive reaction strategy provides the necessary disincentive to prevent selfish misbehavior in the network. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Electrical Engineering and Computer Science.

In order to provide a testing environment for generator control strategies, a wind turbine emulator was developed. First, a mathematical model was developed for a GE 1.5MW wind turbine generator based on modeling data provided by GE. Using this data a function relating maximum power output and wind speed was developed along with a one-mass model of the turbine. The model was implemented in a software simulation along with controllers for a DC motor acting as the wind turbine and a dynamometer acting as the generator. The software simulation was implemented in LabVIEW and read in a data le containing high sample rate (20 Hz) wind speed data, calculated the optimal power from that wind speed, and generated control signals for the DC motor and dynamometer. The e ectiveness of the controller was found by calculating the mean-square error be- tween the optimal power calculated by the simulation turbine model and the actual power produced by the DC motor/dynamometer combination. Two 800 second wind speed data les were used as test inputs for the emulator: a low-speed low-frequency wind pro le and a turbulent or varying-speed wind pro le. The results of the controller development using these two wind speeds show that the turbine inertia is a signi cant factor in following the optimal power output of a wind turbine. The time constant of the generator speed-tracking function used by GE also plays a signi cant role in how quickly the system can respond to changes in wind speed. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Electrical Engineering and Computer Science.

This research attempts to use the creation of popular music in Okinawa as a symbolic resource to reveal attributes related to the making of identity. Popular music in non-Western societies is a useful unit of analysis that can explain how people respond to cultural change and can tell us much about cultural values. The origin of identity studies is both historical and political by nature. However, socio-cultural functions can further expand our understanding of both cultural and political resistance. Popular music as identity is not static and is always in flux. Identity addresses the ongoing relationship between the global (capitalized market) and the local (maintenance of cultural heritage). Negotiation between the two is explained through the use of imagined communities and the concept of place and space. Only through a historical, social, political and economic context is identity making fully realized. The functions of popular music are expressive behaviors which shape and are shaped by social, historical, political and economic experiences. In using the comparative method, the lyrical content and other important features of Okinawan popular music will be contrasted with other Southeast Asian studies. This research will highlight similarities, but will also reveal distinct differences between the formation of identity in both Okinawan and other Southeast Asian communities. / Thesis (M.A.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Anthropology.

In this thesis, two methods of creating multi-layer porous films for DSSCs are examined. They have been designed as possible alternatives for screen printing in laboratory settings. The same precursor chemicals used for screen printing are employed in both the alternative methods, which are designated multi-layer doctor-blading and stamping. Both alternatives are simple and inexpensive, costing $0.86 and $0.89 per DSSC, respectively. Multi-layer doctor bladed cells can be made with up to three layers, while stamped cells can be made with up to eight. The cells produced by these two methods are compared to a sample screen printed cell, with mixed results. The multi-layer doctor bladed cells exhibit lower current densities than a screen printed cell, 68.0 A/m2 compared to 68.9 A/m2. The best performing stamped cell demonstrates a higher current density than the screen printed reference, reaching 82.7 A/m2. It also has a slightly higher efficiency. However, the results from the stamped cells are inconsistent. In order for it to truly become an effective method for creating DSSCs in laboratory settings, the source of this variation must be found and standardized. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Mechanical Engineering.

This thesis documents the development of an adaptive controller designed to control the elastic aircraft dynamics of a generic general aviation aircraft. The elastic aircraft equations of motion are derived using Lagrange’s equation and the principal of virtual work. A minimum kinetic energy axis system is chosen as the body reference axis, which results in structural equations of motion that are decoupled from the rigid body equations of motion. An aerodynamic strip method is utilized to develop closed-form expressions for the longitudinal generalized structural forces. The adaptive controller is designed using a model reference adaptive control scheme, modified for general aviation to use an “E-Z fly” decoupled control architecture, which tracks vertical flight path angle and true airspeed. The adaptive control signal is computed using a weighted least mean square optimization, which gives the control designer more influence on the behavior of the adaptation. A notch filter is designed to decouple the controller and adaptation from the structural modes. The controller is implemented in the MATLAB®/Simulink® environment, and the equations of motion are integrated in simulation for a range of structural flexibility and plant failures. Results show that the controller is capable of handling the uncertainties associated with unmodeled aeroelastic modes. Additionally, the controller shows resilience to “A” and “B” matrix failures, such as 25% loss in elevator and throttle effectiveness. Actuator speed is found to limit the amount of failure the system can recover from, where a fast actuator facilitates adaptation to much larger failures. The notch filter is shown to be successful at decoupling the controller from the structural modes, even for a highly flexible aircraft. Performance without the notch filter is not degraded when the structural modes are outside the controller bandwidth; however, when structural modes fall within the controller bandwidth, the notch filter is required to damp excessive control activity. The proposed controller shows balance between good tracking performance and time delay margin, which is a measure of robustness in the system. This is attributed to the weighted least mean square optimization procedure that gives the control designer more influence over the behavior of the adaption. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Aerospace Engineering.

In practice, channel coefficient information may not be available. Hence, a blind detection may be necessary. In addition, the direct link from a source to a destination may not be available. Therefore, information may have to flow through a relay, which is called a two-hop relay network. This thesis analyses the performance of the two-hop relay network by applying a blind detection assuming a decode-and-forward relay. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Electrical Engineering and Computer Science