Engineering Commons^™

Minimizing Hidden-Node Network Interference By Optimizing Siso And Mimo Spectral Efficiency, Daniel Bliss, Siddhartan Govindasamy

Siddhartan Govindasamy

In this paper, the optimal spectral efficiency (data rate divided by the message bandwidth) that minimizes the probability of causing disruptive interference for ad hoc wireless networks or cognitive radios is investigated. Two basic problem constraints are considered: a given message size, or fixed data rate. Implicitly, the trade being optimized is between longer transmit duration and wider bandwidth versus higher transmit power. Both single-input single-output (SISO) and multiple-input multiple-output (MIMO) links are considered. Here, a link optimizes its spectral efficiency to be a “good neighbor.” The probability of interference is characterized by the probability that the signal power received …

Optimization And Learning In Energy Efficient Cognitive Radio System, Kun Zheng

Doctoral Dissertations

Energy efficiency and spectrum efficiency are two biggest concerns for wireless communication. The constrained power supply is always a bottleneck to the modern mobility communication system. Meanwhile, spectrum resource is extremely limited but seriously underutilized.

Cognitive radio (CR) as a promising approach could alleviate the spectrum underutilization and increase the quality of service. In contrast to traditional wireless communication systems, a distinguishing feature of cognitive radio systems is that the cognitive radios, which are typically equipped with powerful computation machinery, are capable of sensing the spectrum environment and making intelligent decisions. Moreover, the cognitive radio systems differ from traditional wireless …

Stochastic Tools For Network Security: Anonymity Protocol Analysis And Network Intrusion Detection, Lu Yu

All Dissertations

With the rapid development of Internet and the sharp increase of network crime, network security has become very important and received a lot of attention.
In this dissertation, we model security issues as stochastic systems. This allows us to find weaknesses in existing security systems and propose new solutions. Exploring the vulnerabilities of existing security tools can prevent cyber-attacks from taking advantages of the system weaknesses. We consider The Onion Router (Tor), which is one of the most popular anonymity systems in use today, and show how to detect a protocol tunnelled through Tor. A hidden Markov model (HMM) is …

Connecting Architecture, Fitness, Optimizations And Performance Using An Anisotropic Diffusion Filter, Sumedh Naik

All Theses

Over the past decade, computing architectures have continued to exploit multiple levels of parallelism in applications. This increased interest in parallel computing has not only fueled the growth of multi-core processors but has also lead to an emergence of several non-traditional computing architectures like General Purpose Graphical Processing Units (GP-GPUs), Cell Processors, and Field Programmable Gate Arrays (FPGAs). Of these non-traditional computing architectures, GP-GPUs have gained widespread popularity due to their massively parallel computational abilities and relative ease of programmability.
Several software development ecosystems have emerged to harness the power of these parallel architectures. Although several threading libraries like POSIX …

Ammonia Measurements And Emissions From A California Dairy Using Point And Remote Sensors, Kori D. Moore, E. Young, C. Gurell, Michael D. Wojcik, Randy S. Martin, G. E. Bingham, R. L. Pfeiffer, J. H. Prueger, J. L. Hatfield

Civil and Environmental Engineering Faculty Publications

Ammonia (NH3) is an important trace gas species in the atmosphere that can have negative impacts on human, animal, and ecosystem health. Agriculture has been identified as the largest source of NH3, specifically livestock operations. NH3 emissions from a commercial dairy in California were investigated during June 2008. Cattle were held in open-lot pens, except for young calves in hutches with shelters. Solid manure was stored in the open-lot pens. Liquid manure from feed lanes was passed through a solids settling basin and stored in a holding pond. Passive sensors and open-path Fourier transform infrared spectrometers (OP-FTIR) were deployed around …

Blind Source Separation Based On Time-Domain Optimization Of A Frequency-Domain Independence Criterion, Tiemin Mei, Jiangtao Xi, Fuliang Yin, A. Mertins, Jose F. Chicharo

Professor Joe F. Chicharo

A new technique for the blind separation of convolutive mixtures is proposed in this paper. Inspired by the works of Amari, Sabala , and Rahbar, we firstly start from the application of Kullback-Leibler divergence in frequency domain, and then we integrate Kullback-Leibler divergence over the whole frequency range of interest to yield a new objective function which turns out to be time-domain variable dependent. In other words, the objective function is derived in frequency domain which can be optimized with respect to time domain variables. The proposed technique has the advantages of frequency domain approaches and is suitable for very …

Wcet Optimizations And Architectural Support For Hard Real-Time Systems, Yiqiang Ding

Theses and Dissertations

As time predictability is critical to hard real-time systems, it is not only necessary to accurately estimate the worst-case execution time (WCET) of the real-time tasks but also desirable to improve either the WCET of the tasks or time predictability of the system, because the real-time tasks with lower WCETs are easy to schedule and more likely to meat their deadlines. As a real-time system is an integration of software and hardware, the optimization can be achieved through two ways: software optimization and time-predictable architectural support. In terms of software optimization, we fi rst propose a loop-based instruction prefetching approach …

Comparison Between Three Types Of Cable Stayed Bridges Using Structural Optimization, Olfat Sarhang Zadeh

Electronic Thesis and Dissertation Repository

Cable stayed bridges have good stability, optimum use of structural materials, aesthetic, relatively low design and maintenance costs, and efficient structural characteristics. Therefore, this type of bridges are becoming more and more popular and are usually preferred for long span crossings compared to suspension bridges. A cable-stayed bridge consists of one or more towers with cables supporting the bridge deck. In terms of cable arrangements, the most common type of cable stayed bridges are fan, harp, and semi fan bridges. Because of their large size and nonlinear structural behaviour, the analysis of these types of bridges is more complicated than …

Multi-Objective Optimization Of Wind Farm Layouts Under Energy Generation And Noise Propagation, Cristina Amon, Wing Yin Kwong, Joaquin Moran, Michael Morgenroth, David Romeo, Peter Y. Zhang

Publications and Scholarship

Wind farm design deals with the optimal placement of turbines in a wind farm. Past studies have focused on energymaximization, cost-minimization or revenue-maximization objectives. As land is more extensively exploited for onshore wind farms, wind farms are more likely to be in close proximity with human dwellings. Therefore governments, developers, and landowners have to be aware of wind farms’ environmental impacts. After considering land constraints due to environmental features, noise generation remains the main environmental/health concern for wind farm design. Therefore, noise generation is sometimes included in optimization models as a constraint. Here we present continuous-location models for layout optimization …

Heuristic Algorithms For Optimization Of Task Allocation And Result Distribution In Peer-To-Peer Computing Systems, Grzegorz Chmaj, Krzysztof Walkowiak, Michal Tarnawski, Michal Kucharzak

Electrical & Computer Engineering Faculty Research

Recently, distributed computing system have been gaining much attention due to a growing demand for various kinds of effective computations in both industry and academia. In this paper, we focus on Peer-to-Peer (P2P) computing systems, also called public-resource computing systems or global computing systems. P2P computing systems, contrary to grids, use personal computers and other relatively simple electronic equipment (e.g., the PlayStation console) to process sophisticated computational projects. A significant example of the P2P computing idea is the BOINC (Berkeley Open Infrastructure for Network Computing) project. To improve the performance of the computing system, we propose to use the P2P …

Analysis Of Jet Characteristics And Structural Optimization Of A Liquamatic Fire Water Monitor With Self-Swinging Mechanism, Guoliang Hu, Ming Long, Juxing Liang, Weihua Li

Professor Weihua Li

This paper presents analysis and optimization of a liquamatic fire water monitor with a novel self-swinging mechanism. The design of the self-swinging mechanism has adopted a four-bar linkage driven by an impeller. The Fluent software was used to simulate the internal flow performance of the fire water monitor. In particular, the effects of the cross-sectional shape, diameters of the monitor body, inlet water pressure, and drive set of the self-swinging mechanism on the jet characteristics were analyzed. These analyses have led to optimal structural parameters of the flow channel. A prototype of the fire ware monitor was manufactured, and the …

Advanced Design Optimization Of Cold-Formed Steel Portal Frame Buildings, Duoc T. Phan, James B. P. Lim, Tiku T. Tanyimboh, Wei Sha

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The design optimization of cold-formed steel portal frame buildings is considered in this paper. The objective function is based on the cost of the members for the main frame and secondary members (i.e., purlins, girts, and cladding for walls and roofs) per unit area on the plan of the building. A realcoded niching genetic algorithm is used to minimize the cost of the frame and secondary members that are designed on the basis of ultimate limit state. It is shown that the proposed algorithm shows effective and robust capacity in generating the optimal solution, owing to the population’s diversity being …

An Efficient Genetic Algorithm For The Design Optimization Of Cold-Formed Steel Portal Frame Buildings, Duoc T. Phan, James B. P. Lim, Tiku T. Tanyimboh, Wei Sha

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The design optimization of cold-formed steel portal frame buildings is considered in this paper. The real-coded genetic algorithm (GA) optimizer proposed considers both building’s topology (i.e. frame spacing and pitch) and cross-sectional sizes of the main structural members as the decision variables that are optimized. Previous GAs in the literature were characterized by poor convergence including slow progress that usually results in excessive computation times and/or frequent failure to achieve an optimal or near-optimal solution. This is the main issue addressed in this paper. In an effort to improve the performance of the conventional GA, a niching strategy is presented …

Optimum Design Of Mufflers Hybridized With One-Connected Curved Tube Using The Boundary Element Method, Neural Networks, And The Genetic Algorithm, Ying-Chun Chang, Min-Chie Chiu, Ching-Chung Hsieh

Journal of Marine Science and Technology

Recently, research on new techniques for an economical muffler, which is hybridized with a single-connected curved tube, has been applied in the industrial field. Most researchers have explored noise reduction effects based on the transfer matrix method and the stiffness matrix method. However, the maximum noise reduction of a silencer within a constrained space, which frequently occurs in engineering problems, has been neglected. Therefore, the optimum design of mufflers becomes an essential issue. In this paper the shape optimization of a one-connected tube muffler with a fixed length is examined. In order to speed up the optimization assessment, a simplified …

Optimization Models And Algorithms For Truckload Relay Network Design, Hector Andres Vergara Arteaga

Graduate Theses and Dissertations

Driver turnover is a significant problem for full truckload (TL) carriers that operate using point-to-point (PtP) dispatching. The low quality of life of drivers due to the long periods of time they spend away from home is usually identified as one of the main reasons for the high turnover. In contrast, driver turnover is not as significant for less-than-truckload (LTL) carriers that use hub-and-spoke transportation networks which allow drivers to return home more frequently. Based on the differences between TL and LTL, the use of a relay network (RN) has been proposed as an alternative dispatching method for TL transportation …

Multi-Functional Reconfigurable Antenna Development By Multi-Objective Optimization, Xiaoyan Yuan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Antennas are the most essential and significant elements of any wireless communication system. The most common antennas used in wireless communication systems include dipoles/monopoles, horn antennas, loop antennas, and micro-strip antennas. Each type possesses inherent advantages and disadvantages that make them satisfactory for particular applications. The properties of these antennas, however, are fixed by the initial design and cannot be changed. These fixed properties impose restrictions on the overall system performance as the antenna cannot adapt its characteristics in response to the changing propagation parameters of the wireless medium. A reconfigurable antenna, on the other hand, can dynamically change its …

Utilization Of Evolutionary Algorithms To Improve Engineering Decision - Making, Robert Gerhart

Culminating Projects in Mechanical and Manufacturing Engineering

While genetic algorithms have been explored academically, and in at least two known cases, commercialized, they still seem to be an underutilized technique for solving engineering management problems. One of the reasons for this is the general lack of awareness and understanding about genetic algorithms. Another reason is that genetic algorithms have generally been viewed as being too costly in terms of computing resources to implement for complex problems. This paper examines an example management problem and an example genetic algorithm that was developed to solve it in order to illustrate the applicability of such algorithms to similar or more …

Two-Step Optimal Thermal Generation Scheduling, B Fardanesh, F. Eugenio Villaseca

F. Eugenio Villaseca

A new approach to the solution of the optimal thermal generation scheduling problem is presented. The problem is solved in two steps. As a first step, the optimal production schedule for the next day is obtained based on a daily load forecast, reserve capacity requirements, and present status of generating units. The second-step algorithm uses the results of the first step and adjusts the previous schedule to meet new constraints developed during the course of the day. Variable truncation dynamic programming is proposed as a new method to reduce computation effort. To eliminate the need for solving the entire problem …

Identification Of Hemodynamically Optimal Coronary Stent Designs Based On Vessel Caliber, Timothy J. Gundert, Alison L. Marsden, Weiguang Yang, David S. Marks, John F. Ladisa

Biomedical Engineering Faculty Research and Publications

Coronary stent design influences local patterns of wall shear stress (WSS) that are associated with neointimal growth, restenosis, and the endothelialization of stent struts. The number of circumferentially repeating crowns N_C for a given stent de- sign is often modified depending on the target vessel caliber, but the hemodynamic implications of altering N_C have not previously been studied. In this investigation, we analyzed the relationship between vessel diameter and the hemodynamically optimal N_C using a derivative-free optimization algorithm coupled with computational fluid dynamics. The algorithm computed the optimal vessel diameter, defined as minimizing the area of stent-induced …

Logistics Orchestration Modeling And Evaluation For Humanitarian Relief, Hoong Chuin Lau, Zhengping Li, Xin Du, Heng Jiang, Robert De Souza

Research Collection School Of Computing and Information Systems

This paper proposes an orchestration model for post-disaster response that is aimed at automating the coordination of scarce resources that minimizes the loss of human lives. In our setting, different teams are treated as agents and their activities are "orchestrated" to optimize rescue performance. Results from simulation are analysed to evaluate the performance of the optimization model.

Constrained Control And Optimization Of Tubular Solid Oxide Fuel Cells For Extending Cell Lifetime, Ben Spivey, John Hedengren, Thomas F. Edgar

Faculty Publications

Extending fuel cell lifetime is a necessary objective for reducing fuel cell power generation cost of electricity. Capital costs comprise the most significant fraction of the cost of electricity. Reducing the frequency of fuel cell replacement can be achieved by implementing a control strategy that prevents excursions into operating regions causing failure. In this paper we implement a constrained MIMO model predictive controller (MPC) to avoid the failure modes relevant for a high-temperature tubular solid oxide fuel cell (SOFC) system while performing load-following. The primary causes of failure are catalyst poisoning, fuel or air starvation, carbon deposition, and microcracking. Prior …

Advanced Intelligent Control And Optimization For Cardiac Pacemaker Systems, Wei Shi

Dissertations

Since cardiovascular diseases are major causes of morbidity and mortality in the developed countries and the number one cause of death in the United States, their accurate diagnosis and effective treatment via advanced cardiac pacemaker systems have become very important. Intelligent control and optimization of the pacemakers are significant research subjects. Serious but infrequently occurring arrhythmias are difficult to diagnose. The use of electrocardiogram (ECG) waveform only cannot exactly distinguish between deadly abnormalities and temporary arrhythmias. Thus, this work develops a new method based on frequency entrainment to analyze pole-zero characteristics of the phase error between abnormal ECG and entrained …

Fuzzy Differential Evolution Algorithm, Dejan Vucetic

Electronic Thesis and Dissertation Repository

The Differential Evolution (DE) algorithm is a powerful search technique for solving global optimization problems over continuous space. The search initialization for this algorithm does not adequately capture vague preliminary knowledge from the problem domain. This thesis proposes a novel Fuzzy Differential Evolution (FDE) algorithm, as an alternative approach, where the vague information of the search space can be represented and used to deliver a more efficient search. The proposed FDE algorithm utilizes fuzzy set theory concepts to modify the traditional DE algorithm search initialization and mutation components. FDE, alongside other key DE features, is implemented in a convenient decision …

Process Optimization Of Boatmate Trailers, Llc, Jamie M. Smotherman, Jasmine L. Kelley

Chancellor’s Honors Program Projects

No abstract provided.

A New Metaheuristic Algorithm Motivated By The Rooting Phenomena In Plants, Behzad Nemati

All Theses

In this thesis, we present a new metaheuristic algorithm for analyzing challenging optimization problems. Initial testing reveals the potential for the algorithm, which is based on the rooting phenomena found in plants in nature, to quickly produce effective solutions to challenging combinatorial optimization problems in the class NP. We present computational results describing the proposed metaheuristic's efficacy for an important class of scheduling problems and discuss areas of future work and application.

Probabilistic Qos Analysis In Wireless Sensor Networks, Yunbo Wang

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Emerging applications of wireless sensor networks (WSNs) require real-time quality of service (QoS) guarantees to be provided by the network. Traditional analysis work only focuses on the first-order statistics, such as the mean and the variance of the QoS performance. However, due to unique characteristics of WSNs, a cross-layer probabilistic analysis of QoS performance is essential. In this dissertation, a comprehensive cross-layer probabilistic analysis framework is developed to investigate the probabilistic evaluation and optimization of QoS performance provided by WSNs. In this framework, the distributions of QoS performance metrics are derived, which are natural tools to discover the probabilities to …

Design Of Meta-Materials Outside The Homogenization Limit Using Multiscale Analysis And Topology Optimization, Christopher Czech

All Dissertations

The field of meta-materials engineering has largely expanded mechanical design possibilities over the last two decades; some notable design advances include the systematic engineering of negative Poisson's ratio materials and functionally graded materials, materials designed for optimal electronic and thermo-mechanical performances, and the design of materials under uncertainty. With these innovations, the systematic engineering of materials for design-specific uses is becoming more common in industrial and military uses. The motivation for this body of research is the design of the shear beam for a non-pneumatic wheel. Previously, a design optimization of a finite element model of the non-pneumatic wheel was …

Optimization And Design For Heavy Lift Launch Vehicles, Paul Andreas Ritter

Masters Theses

The simulation and evaluation of an orbital launch vehicle requires consideration of numerous factors. These factors include, but are not limited to the propulsion system, aerodynamic effects, rotation of the earth, oblateness, and gravity. A trajectory simulation that considers these different factors is generated by a code developed for this thesis titled Trajectories for Heavy-lift Evaluation and Optimization (THEO). THEO is a validated trajectory simulation code with the ability to model numerous launch configurations. THEO also has the capability to provide the means for an optimization objective. Optimization of a launch vehicle can be specified in terms of many different …

Development Of Novel Solar Tracking And Heat Extracting Technologies, Hassan Latif Hassan

Electronic Thesis and Dissertation Repository

The global energy and water crises are looming due to the exponential population growth and the shrinking reserves of conventional fossil fuels and fresh water. The present research is aimed at the development of novel components/technologies that would lead to efficient and affordable concentrated solar thermal systems. A novel dual-axis solar tracking system has been developed, built and extensively tested on a field parabolic dish solar collector model. The tracker has two main novel components; active dual axis tracker; and load compensator. The tracker is characterized with simplicity and reliability. Two geometries of novel conical thermal receivers were designed, constructed …

Optimizing Fermentation Medium To Produce Cyclosporin A Using Response Surface Methodology, Rofiq Sunaryanto

Makara Journal of Technology

Response surface methodology (RSM) is a three factorial model which illustrates the relationship between one or more independent variables. RSM can be used to optimize the fermentation medium for the production of Cyclosporin A from the isolate Tolypocladium inflatum. The optimal point of the response surface area is predicted by using a seconddegree polynomial model and applying the statistic model obtained from the central composite design (CCD). The results of optimizing the fermentation medium for Cyclopsorin using the three independent variables of glucose, casein, and KH2PO4 show that all three of the independent variables affect the production of Cyclosporin A. …