Channel assignment in wireless mesh network (WMN) aims at improving the network throughput by utilizing multiple orthogonal frequency channels to minimize the interference. Interference can be categorized as coordinated and non-coordinated, depending upon the relative location of the interfering links. Compared to coordinated interference, non-coordinated interference has a severe adverse impact on throughput. This thesis is based on the hypothesis that the network throughput can be improved significantly, if channel assignment minimizes non-coordinated interference with priority. We propose a static and centralized channel assignment scheme CCAS to show the effectiveness of the hypothesis. The cluster-based approach of CCAS minimizes non-coordinated interference with reduced complexity. CCAS improves the network throughput by upto 80%, compared to the existing schemes. We propose topology control scheme MATS that constructs low interference multipath network topology using a subset of links from physical topology. We report an additional improvement of upto 10% in the network throughput, when CCAS assigns channels to the links selected by MATS. In the final part of the thesis, we formulate generalized channel assignment as an optimization problem, accounting for real network traffic. The objective of the problem is to select the channels for links such that maximum incident traffic can be transmitted over the links, while ensuring a fair distribution of throughput amongst links and elimination of non-coordinated interference. For a given network and incident traffic, the solution to this problem generates the channel assignment resulting in optimal network throughput. We propose dynamic and distributed scheme LYCAS as an approximate solution to the problem. LYCAS employs MATS to construct network topology and cluster-based approach of CCAS to minimize non-coordinated interference. In addition, it periodically updates the assignment of channels to adapt to the changing traffic load. LYCAS achieves upto 68% of the optimal network throughput and upto 72% of optimal aggregate end-to-end throughput of multi-hop flows. It outperforms the existing schemes by a factor of 2.

abstract: The purpose of this paper is to introduce a new method of dividing wireless communication (such as the 802.11a/b/g/n and cellular UMTS MAC protocols) across multiple unreliable communication links (such as Ethernet). The purpose is to introduce the appropriate hardware, software, and system architecture required to provide the basis for a wireless system (using a 802.11a/b/g/n and cellular protocols as a model) that can scale to support thousands of users simultaneously (say in a large office building, super chain store, etc.) or in a small, but very dense communication RF region. Elements of communication between a base station and a Mobile Station will be analyzed statistically to demonstrate higher throughput, fewer collisions and lower bit error rates (BER) with the given bandwidth defined by the 802.11n wireless specification (use of MIMO channels will be evaluated). A new network nodal paradigm will be presented. Alternative link layer communication techniques will be recommended and analyzed for the affect on mobile devices. The analysis will describe how the algorithms used by state machines implemented on Mobile Stations and Wi-Fi client devices will be influenced by new base station transmission behavior. New hardware design techniques that can be used to optimize this architecture as well as hardware design principles in regard to the minimal hardware functional blocks required to support such a system design will be described. Hardware design and verification simulation techniques to prove the hardware design will accommodate an acceptable level of performance to meet the strict timing as it relates to this new system architecture. / Dissertation/Thesis / JMP Analysis Files / Defense Presentation / M.S. Electrical Engineering 2014

This dissertation presents the results of a series of studies on dynamic stabilisation of CoMan, which is actuated by series elastic actuators. The main goal of this dissertation is to dynamically stabilise the humanoid robot on the floor by the simplest multivariate feedback control for the purpose of walking. The multivariable scheme is chosen to take into account the joints' interactions, as well as providing a systematic way of designing the feedback system to improve the bandwidth and tracking performance of CoMan's existing PID control. A detailed model is derived which includes all the motors and joints state variables and their multibody interactions which are often ignored in the previous studies on bipedal robots in the literature. The derived dynamic model is then used to design multivariable optimal control feedback and observers with a mathematical proof for the relative stability and robustness of the closed loop system in face of model uncertainties and disturbances. In addition, two decentralized optimal feedback design algorithms are presented that explicitly take the compliant dynamics and the multibody interactions into account while providing the mathematical proof for the stability of the overall system. The purpose of the proposed decentralized control methods is to provide a systematic model based PDPID design to replace the existing PID controllers which are derived by a trial and error process. Moreover, the challenging constrained and compliant motion of the robot in double support is studied where a novel constrained feedback design is proposed which directly takes the compliance dynamics, interactions and the constraints into account to provide a closed loop feedback tracking system that drives the robot inside the constrained subspace. This method of control is particularly interesting since most control methods applied to closed kinematic chains (such as the double support phase) are over complicated for implementation purposes or have an ad-hoc approach to controller design. In terms of walking trajectory generation, an extension to the ZMP walking trajectory generation is proposed to utilise the CoMan's upper body to tackle the non-minimum phase behaviour that is faced in trajectory generation. Simple inverted pendulum models of walking are then used to study the maximum feasible walking speed and step size where parameters of CoMan are used to provide numerical upperbounds on the step size and walking speed. Use of straight knee and toe push-off during walking is shown to be beneficial for taking larger step lengths and hence achieving faster walking speeds. Subsequently, the designed tracking systems are then applied to a dynamic walking simulator which is developed during this PhD project to accurately model the compliant walking behaviour of the CoMan. A walking gait is simulated and visualized to show the effectiveness of the developed walking simulator. Moreover, the experimental results and challenges faced during the implementation of the designed tracking control systems are discussed where it is shown that the LQR feedback results in 50% less control effort and tracking errors in comparison with CoMan's existing independent PID control. This advantage directly affects the feasible walking speed. In addition, a set of standard and repeatable tests for CoMan are designed to quantify and compare the performance of various control system designs. Finally, the conclusions and future directions are pointed out.

Since its foundation, revenue management techniques on aggregate have added billions of dollars to many firms' bottom lines, while using existing products or services and existing sets of consumers (Cross, Higbie, and Cross, 2010). The recent rapid changes in the business environment have forced firms to adopt strategies that will fit their overall strategies to aid in their survival and success (Pechlaner and Sauerwein, 2002). As a result of the modern reality of business, academic literature has not yet been able to address many important considerations. An example is RM implementation strategies and the performance outcomes as a result of these decisions. This study investigated the advantages and disadvantages of implementation of RM strategies; in-house, centralized, and outsourced. This was followed by the make or buy decision, specifically focusing on Transaction Cost Economics and the Resource Based View to investigate antecedents of outsourcing intention, and if and how these different strategies affect hotel properties' performance. Data were collected using an online survey of lodging properties located in the U.S. in October 2014. A total of 374 usable responses for outsourcing intention study and 591 usable responses for the performance study were collected. Factor analysis, hierarchical multiple regression, repeated measures ANOVA, regression analysis, and pairwise comparison analysis were the statistical analyses used in the study. The results found that specificity is significant and negatively associated with outsourcing intention. In addition, uncertainty is significant and positively associated with outsourcing intention as proposed. The moderating effect of organizational capability is significant and changes from base model to final model with the moderator being statistically significant. The findings of regression and a pairwise comparison test confirmed the difference in strategy choice on performance for US hotels, giving us insights into the importance of selecting the strategy that is optimal for a given property. / Ph. D.

The purpose of the non-experimental quantitative research study was to identify if there is a significant difference between the types of budget model an institution utilizes, institutional size, and student enrollment, retention, and graduation rates. This study was to identify if there is significant difference between institutional size and the type budget model utilized. Member institutions of the American Association of State Colleges and Universities (AASCU) were selected to participate in this study due to their similarities of mission and admissions policy. AASCU institutions share a common mission that focuses on access, innovation, regional support, and inclusion. AASCU institutions are all public regional institutions. Larger institutions within the study presented significantly higher retention and graduation rates compared to medium size institutions. I used the Carnegie classification of size as institutions that have enrollments less than 3,000 as small, institutions that have enrollments less than 10,000 as medium, and institutions with enrollments greater than 10,000 as large. I study found no significant difference in the types of budget model utilized and the student outcomes related to enrollment, retention, or graduation rates. I did indicate that institutions that utilized a more decentralized budgeting approach had higher enrollment percentages and higher retention and graduation rates than institutions that utilized a centralized budget model. I also did not identify any significant difference in the size of an institution and the type of budget model utilized.

No description available.

No description available.

Modern power substations continue to use hardware that is dated and resistant to modernization. This document discusses the basics of substations, identifies their weaknesses, and suggests a method of improvement. This suggestion implements a centralized protection and control system to make the overall system more robust and flexible to the ever changing power system landscape. / Master of Science

Industries such as automotive and industrial automation are pushing the limits of networking technology. The Time-Sensitive Networking (TSN) standards offer a promising solution that can meet the demands of high-bandwidth applications with strict timing constraints, allowing time-critical traffic to coexist with other traffic. However, TSN is relatively new, with much research necessary before it is usable in the industry. This thesis addresses the problem of the common manual configuration of end stations, being time-consuming and error-prone. Through exploring the TSN standards, this thesis attempts to solve the configuration problem by providing a proof-of-concept for both design and implementation of a software architecture managing the end stations and automating their configuration process. Adopting an agile and iterative approach made the complexity of TSN manageable. Furthermore, this thesis has been guided by the research question: How can the configuration of a TSN end station be automated? The design was split into three components: an interface, a configuration manager, and a TSN library. In addition, a communication protocol between the end stations and the Centralized Network Configuration (CNC) is established. The implementation of the proposed design used Python for all three modules in the end station management software, with the REST protocol for the interface. After presenting the implementation, it was evaluated to show the performance of the implemented end station management software. The results showed that the management software would likely not be the bottleneck, as other components it depends on are considerably slower. This thesis and its research contribution offer a practical foundation for continued research and development, such as investigating the configuration of the end stations, providing proofs-of-concept for engineering tools with specific use cases, and finalizing a TSN system. / Industrier som fordons- och industriautomation tänjer på gränserna av nätverksteknik. Time-Sensitive Networking (TSN) standarderna är en lovande lösning som lovar att möta kraven för applikationer med krav på hög bandbredd och strikta tidskrav, som samtidigt tillåter tidskritisk trafik att existera tillsammans med annan trafik. Dock är TSN relativt nytt och i stort behov av mer forskning innan det kan användas i industrin. Den här avhandlingen adresserar problemet med manuell konfiguration av ändstationer, som är både tidskrävande och felbenäget. Genom att utforksa TSN standarderna försöker den här avhandlingen lösa konfigurationsproblemet genom att ta fram ett koncept för design och implementation av en mjukvaruarkitektur för att hantera ändstationer och automatisera deras konfigurationsprocess. Genom att anta en agil och iterativ metod blev komplexiteten hos TSN hanterbar. Dessutom har den här avhandlingen styrts av forskningsfrågan: Hur kan konfigurationen av TSN ändstationer automatiseras? Designen delades upp i tre komponenter: ett gränssnitt, en konfigurationshanterare, samt ett TSN-bibliotek. Utöver detta etablerades ett kommunikationsprotokoll mellan ändstationer och en Centralized Network Configuration (CNC). Implementationen av den föreslagna designen använde sig av Python för de tre komponenterna, med REST-protokollet för gränssnittet. Efter presentationen av implementationen utvärderades den för att visa prestandan hos den implementerade mjukvaran för ändstationen. Resultaten visade att mjukvaran sannolikt inte skulle vara en flaskhals, då andra komponenter som den är beroende av, är betydligt långsammare. Den här avhandligen och dess forskningsbidrag erbjuder en praktiskt grund för fortsatt forskning och utveckling, som undersökning av konfigurationen för ändstationer, framtagning av koncept för ingenjörsverktyg med specifika användningsfall, samt att slutföra ett TSN-system.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Recent years have seen a sharp rise in the size of satellite constellations. The monitoring and analysis tools in use today, however, were developed for smaller constellations and are ill-equipped to handle the increased volume of telemetry data. A new technology that can accommodate vast quantities of data is 3-D visualization. Data is abstracted to show the degree to which it deviates from normal, allowing an analyst to absorb the status of thousands of parameters in a single glance. Trend alarms notify the user of dangerous trends before data exceeds normal limits. Used appropriately, 3-D visualization can extend the life of a satellite by ten to twenty percent.