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Optimization

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Articles 271 - 300 of 656

Full-Text Articles in Physical Sciences and Mathematics

Optimization Under Fuzzy Constraints: From A Heuristic Algorithm To An Algorithm That Always Converges, Vladik Kreinovich, Juan Carlos Figueroa-Garcia Jul 2018

Optimization Under Fuzzy Constraints: From A Heuristic Algorithm To An Algorithm That Always Converges, Vladik Kreinovich, Juan Carlos Figueroa-Garcia

Departmental Technical Reports (CS)

An efficient iterative heuristic algorithm has been used to implement Bellman-Zadeh solution to the problem of optimization under fuzzy constraints. In this paper, we analyze this algorithm, explain why it works, show that there are cases when this algorithm does not converge, and propose a modification that always converges.


Optimization Studies And Applications: In Retail Gasoline Market, Daero Kim Jun 2018

Optimization Studies And Applications: In Retail Gasoline Market, Daero Kim

Electronic Thesis and Dissertation Repository

The study of the retail gasoline market is of great interest in financial economics, since it allows many theories about price formation, oligopolistic markets, and consumer search to be tested. In addition, the risk management of gasoline prices is an important instance of the management of any consumable commodity cost. For the retailer, the tool of dynamic pricing may be found to be useful.

This thesis contributes to the study of retail gasoline markets in three main ways, each in its own paper. The first paper tests various economic models to confirm earlier results about pricing behavior in retail gasoline …


Optimization Of Superhydrophobic Surface Production Using Ambient-Dried Silica-Based Aerogels, Elizabeth Donlon Jun 2018

Optimization Of Superhydrophobic Surface Production Using Ambient-Dried Silica-Based Aerogels, Elizabeth Donlon

Honors Theses

Superhydrophobic surfaces exhibit particular properties that make them functional in various anti-sticking, anti-contamination, self-cleaning and drag reduction applications. Though such surfaces are found in nature - most notably the lotus leaf - they are difficult to produce. There are numerous methods and techniques for fabricating superhydrophobic surfaces. One such method is the sol-gel method, in which aerogel, a highly porous and lightweight material that can be made hydrophobic or superhydrophobic, is coated onto a surface. The purpose of this project is to devise a simple and repeatable procedure for making hydrophobic silica aerogel coatings that can be used for drag …


Optimizing Tensegrity Gaits Using Bayesian Optimization, James Boggs Jun 2018

Optimizing Tensegrity Gaits Using Bayesian Optimization, James Boggs

Honors Theses

We design and implement a new, modular, more complex tensegrity robot featuring data collection and wireless communication and operation as well as necessary accompanying research infrastructure. We then utilize this new tensegrity to assess previous research on using Bayesian optimization to generate effective forward gaits for tensegrity robots. Ultimately, we affirm the conclusions of previous researchers, demonstrating that Bayesian optimization is statistically significantly (p < 0:05) more effective at discovering useful gaits than random search. We also identify several flaws in our new system and identify means of addressing them, paving the way for more effective future research.


Multi-Stop Routing Optimization: A Genetic Algorithm Approach, Abbas Hommadi May 2018

Multi-Stop Routing Optimization: A Genetic Algorithm Approach, Abbas Hommadi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In this research, we investigate and propose new operators to improve Genetic Algorithm’s performance to solve the multi-stop routing problem. In a multi-stop route, a user starts at point x, visits all destinations exactly once, and then return to the same starting point. In this thesis, we are interested in two types of this problem. The first type is when the distance among destinations is fixed. In this case, it is called static traveling salesman problem. The second type is when the cost among destinations is affected by traffic congestion. Thus, the time among destinations changes during the day. In …


User-Centric Privacy Preservation In Mobile And Location-Aware Applications, Mingming Guo Apr 2018

User-Centric Privacy Preservation In Mobile And Location-Aware Applications, Mingming Guo

FIU Electronic Theses and Dissertations

The mobile and wireless community has brought a significant growth of location-aware devices including smart phones, connected vehicles and IoT devices. The combination of location-aware sensing, data processing and wireless communication in these devices leads to the rapid development of mobile and location-aware applications. Meanwhile, user privacy is becoming an indispensable concern. These mobile and location-aware applications, which collect data from mobile sensors carried by users or vehicles, return valuable data collection services (e.g., health condition monitoring, traffic monitoring, and natural disaster forecasting) in real time. The sequential spatial-temporal data queries sent by users provide their location trajectory information. The …


A Holistic Computational Approach To Boosting The Performance Of Protein Search Engines, Majdi Ahmad Mosa Maabreh Apr 2018

A Holistic Computational Approach To Boosting The Performance Of Protein Search Engines, Majdi Ahmad Mosa Maabreh

Dissertations

Despite availability of several proteins search engines, due to the increasing amounts of MS/MS data and database sizes, more efficient data analysis and reduction methods are important. Improving accuracy and performance of protein identification is a main goal in the community of proteomic research. In this research, a holistic solution for improvement in search performance is developed.

Most current search engines apply the SEQUEST style of searching protein databases to define MS/MS spectra. SEQUEST involves three main phases: (i) Indexing the protein databases, (ii) Matching and Ranking the MS/MS spectra and (iii) Filtering the matches and reporting the final proteins. …


Virtualization In Wireless Sensor Networks: Fault Tolerant Embedding For Internet Of Things, Omprakash Kaiwartya, Abdul Hanan Abdullah, Yue Cao, Jaime Lloret, Sushil Kumar, Rajiv Ratn Shah, Mukesh Prasad, Shiv Prakash Apr 2018

Virtualization In Wireless Sensor Networks: Fault Tolerant Embedding For Internet Of Things, Omprakash Kaiwartya, Abdul Hanan Abdullah, Yue Cao, Jaime Lloret, Sushil Kumar, Rajiv Ratn Shah, Mukesh Prasad, Shiv Prakash

Research Collection School Of Computing and Information Systems

Recently, virtualization in wireless sensor networks (WSNs) has witnessed significant attention due to the growing service domain for IoT. Related literature on virtualization in WSNs explored resource optimization without considering communication failure in WSNs environments. The failure of a communication link in WSNs impacts many virtual networks running IoT services. In this context, this paper proposes a framework for optimizing fault tolerance in virtualization in WSNs, focusing on heterogeneous networks for service-oriented IoT applications. An optimization problem is formulated considering fault tolerance and communication delay as two conflicting objectives. An adapted non-dominated sorting based genetic algorithm (A-NSGA) is developed to …


The Model Of Operational Control Of The Production Process In Cotton Processing Enterprise, F. Yusupov Mar 2018

The Model Of Operational Control Of The Production Process In Cotton Processing Enterprise, F. Yusupov

Central Asian Problems of Modern Science and Education

Mathematical formalization of the test process is reduced to the construction of the static model of operational control of technological progress of the primary processing of raw cotton, thus it is considered a fixed process parameters and usage of digital technological modes


Model Of Optimization Of Technological Regimes Of Oilextraction Production For The Minimum Costs, G. Kh. Abdullayeva Mar 2018

Model Of Optimization Of Technological Regimes Of Oilextraction Production For The Minimum Costs, G. Kh. Abdullayeva

Central Asian Problems of Modern Science and Education

In the stochastic manufacturing process conditions and classification of end products of oil extraction production by intersecting quality areas, manufacturing costs can be reduced by varying the values for the number of modes and their coordinates. 25 Built in the model optimization mode technology is designed to surround the purposes of (current) planning production of oil extraction enterprise products


Multigeneration Product Diffusion In The Presence Of Strategic Consumers, Zhiling Guo, Jianqing Chen Mar 2018

Multigeneration Product Diffusion In The Presence Of Strategic Consumers, Zhiling Guo, Jianqing Chen

Research Collection School Of Computing and Information Systems

Frequent new product releases pose significant challenges for firms as they manage successive generations of product diffusion. We develop an analytical model to study the effect of different purchase options by strategic consumers on a firm's profit and the firm's strategies for the timing and pricing of its successive generations of product diffusion. We show that consumers' strategic behavior, although adversely affecting the sales of the first-generation product, positively influences the sales of the second-generation product through an initial “seeding” effect. The influence of strategic consumers on profit and sales depends largely on the discount-to-price ratio of the first generation …


Gradient Estimation For Attractor Networks, Thomas Flynn Feb 2018

Gradient Estimation For Attractor Networks, Thomas Flynn

Dissertations, Theses, and Capstone Projects

It has been hypothesized that neural network models with cyclic connectivity may be more powerful than their feed-forward counterparts. This thesis investigates this hypothesis in several ways. We study the gradient estimation and optimization procedures for several variants of these networks. We show how the convergence of the gradient estimation procedures are related to the properties of the networks. Then we consider how to tune the relative rates of gradient estimation and parameter adaptation to ensure successful optimization in these models. We also derive new gradient estimators for stochastic models. First, we port the forward sensitivity analysis method to the …


Integrated Strategies For Sustainable Wastewater-Based Algal Biofuel Production And Environmental Mitigation In The Us, Javad Roostaei Jan 2018

Integrated Strategies For Sustainable Wastewater-Based Algal Biofuel Production And Environmental Mitigation In The Us, Javad Roostaei

Wayne State University Dissertations

Integration of algae cultivation with wastewater treatment has received increasing interest as a cost-effective strategy for biofuel production. However, there has been no full assessment of algal biofuel production with wastewater on macro-scale by taking into account wastewater resources, land availability, CO2 emission resources, and geographic variation. This research addressed and evaluated the use of wastewater for algae cultivation, in terms of modeling and laboratory experiments. The first goal of this research was to develop a spatially explicit lifecycle model, by integrating life cycle assessment (LCA), and Geographic Information Systems (GIS) analysis, for the evaluation of the environmental and economic …


Optimization And Control Of An Array Of Wave Energy Converters, Jianyang Lyu Jan 2018

Optimization And Control Of An Array Of Wave Energy Converters, Jianyang Lyu

Dissertations, Master's Theses and Master's Reports

This study explored optimal configuration of both the array layout and the dimension of each WEC in the array. The array contains heaving buoys with full interaction and exact hydrodynamics. Optimization of dimension was done on each WEC in the array with a given optimal layout, and a higher q-factor was achieved. Both impedance matching optimal control and derivative control were employed, which provides both theoretical maximum energy and a more realistic case. Then the work was expanded to optimization of both the array layout and the dimension of each WEC in the array. An average of 39.21% higher q-factor …


Some Results On A Class Of Functional Optimization Problems, David Rushing Dewhurst Jan 2018

Some Results On A Class Of Functional Optimization Problems, David Rushing Dewhurst

Graduate College Dissertations and Theses

We first describe a general class of optimization problems that describe many natu- ral, economic, and statistical phenomena. After noting the existence of a conserved quantity in a transformed coordinate system, we outline several instances of these problems in statistical physics, facility allocation, and machine learning. A dynamic description and statement of a partial inverse problem follow. When attempting to optimize the state of a system governed by the generalized equipartitioning princi- ple, it is vital to understand the nature of the governing probability distribution. We show that optimiziation for the incorrect probability distribution can have catas- trophic results, e.g., …


Highly-Configurable Multi-Objective Optimization For Physical Parameter Extraction Using Terahertz Time-Domain Spectroscopy, Andrew John Niklas Jan 2018

Highly-Configurable Multi-Objective Optimization For Physical Parameter Extraction Using Terahertz Time-Domain Spectroscopy, Andrew John Niklas

Browse all Theses and Dissertations

The use of terahertz time-domain spectroscopy provides one of the most versatile and promising techniques for the robust determination of optical parameters, which is needed to enable identification of materials for quality control, materials science advancement, tamper prevention, drug enforcement, and hidden explosives detection. Previously, the state-of-the-art relied on legacy error measures for minimization of simulation error and the standard practice was to use a single unique measurement for each unknown material in a sample. Successful optical parameter extraction for uniformly varying optical property materials is correlated with low variation in extracted optical properties. This work advances the state-of-the-art in …


Computational Methods In Civil Engineering, Nir Krakauer Jan 2018

Computational Methods In Civil Engineering, Nir Krakauer

Open Educational Resources

No abstract provided.


Minimizing Container Weight, Ibrahim Alomran Jan 2018

Minimizing Container Weight, Ibrahim Alomran

Undergraduate Journal of Mathematical Modeling: One + Two

Increased globalization has resulted in increased competition in the shipping industry. Since large carriers control over 70% of the total shipping industry, small carriers are left with only 30% of the market share to compete for. Ultimately, profit margins for small carriers have become very minimal. There is, therefore, need to develop a strategy that will aid in optimizing the profits of carriers. The goal of this paper is to develop a model that will help determine the minimum weight for a particular container design. The validity of the model is important in the sense that minimum container weight will …


Damping Wide-Area Oscillations In Power Systems: A Model Predictive Controldesign, Emrah Biyik, Munir Husein Jan 2018

Damping Wide-Area Oscillations In Power Systems: A Model Predictive Controldesign, Emrah Biyik, Munir Husein

Turkish Journal of Electrical Engineering and Computer Sciences

Electromechanical oscillations in power systems have been observed ever since synchronous generators were interconnected to provide reliability and higher generation capacity, and they have become a severe threat for the safe and economic operation of modern interconnected power grids. To dampen these oscillations, wide-area damping controllers (WADCs) have been introduced by utilizing wide-area measurement systems and synchronized phasor measurement units. In this paper, we present a systematic approach for designing WADCs using a model predictive control (MPC) technique to damp interarea oscillations in the power system. The MPC controller computes optimal control signals for the excitation system of a remote …


Ionolab-Map: An Automatic Spatial Interpolation Algorithm For Total Electron Content, Muhammet Necat Devi̇ren, Feza Arikan Jan 2018

Ionolab-Map: An Automatic Spatial Interpolation Algorithm For Total Electron Content, Muhammet Necat Devi̇ren, Feza Arikan

Turkish Journal of Electrical Engineering and Computer Sciences

Investigation of the variability of total electron content (TEC) is one of the most important parameters of the observation and monitoring of space weather, which is the main cause of signal disturbance in space-based communication, positioning, and navigation systems. TEC is defined as the total number of electrons on a ray path. The Global Positioning System (GPS) provides a cost-effective solution for the estimation of TEC. Due to various physical and operational disturbances, TEC may have temporal and spatial domain gaps. Global ionospheric maps (GIMs) provide worldwide TEC with 1- to 2-h temporal resolution and $2.5^{\circ}\, \times 5^{\circ}$ spatial resolution …


Application Of Domination Integrity Of Graphs In Pmu Placement In Electric Power Networks, Mariappan Saravanan, Ramalingam Sujatha, Raman Sundareswaran, Muthu Selvan Balasubramanian Jan 2018

Application Of Domination Integrity Of Graphs In Pmu Placement In Electric Power Networks, Mariappan Saravanan, Ramalingam Sujatha, Raman Sundareswaran, Muthu Selvan Balasubramanian

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we propose the application of the concept of power domination integrity to an electric power network. A phasor measurement unit (PMU) is used to analyze and control the power system by measuring voltage phase in electrical nodes and transmission lines. Due to the high cost of PMUs, it is necessary to minimize the number of PMUs such that the depth of observability is ensured. Placing PMUs in a network can be formulated as a graph theoretic problem of finding the minimum number of nodes (PMUs) in a graph that has a maximum number of links with other …


The Impact Of Transmission Power Levels Set Size On Lifetime Of Wireless Sensor Networks In Smart Grids, Hüseyi̇n Uğur Yildiz Jan 2018

The Impact Of Transmission Power Levels Set Size On Lifetime Of Wireless Sensor Networks In Smart Grids, Hüseyi̇n Uğur Yildiz

Turkish Journal of Electrical Engineering and Computer Sciences

Wireless sensor networks (WSNs) have been confirmed as one of the most promising technologies for many smart grid (SG) applications due to their low complexity and inexpensive costs. A typical WSN is formed with numerous battery limited sensor nodes mounted on critical components of a SG system for monitoring applications. Acquired monitoring data by sensor nodes are conveyed to the base station generally by using multihop communication techniques. WSN-based SG applications encounter severe propagation losses due to extreme channel conditions of the SG environment. In order to reduce possible packet errors caused by channel variations, transmission power control approaches can …


An Elitist Approach For Solving The Traveling Salesman Problem Using An Animalmigration Optimization Algorithm, Ezgi̇ Ülker Jan 2018

An Elitist Approach For Solving The Traveling Salesman Problem Using An Animalmigration Optimization Algorithm, Ezgi̇ Ülker

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an improved version of the animal migration optimization (AMO) algorithm for solving the traveling salesman problem (TSP), which is classified as a combinatorial NP-hard problem. AMO is one of the recent metaheuristic algorithms inspired by the migration behavior of animals and has been efficiently applied to a variety of optimization problems. The algorithm is improved by reconstructing the neighborhood topology of each animal during the migration. This modified algorithm is called the elitist animal migration optimization (ELAMO) algorithm, since elitism is introduced as a way in which the positions of the leaders are considered for the neighborhood …


Choice Of Battery Energy Storage For A Hybrid Renewable Energy System, Kusum Lata Tharani, Ratna Dahiya Jan 2018

Choice Of Battery Energy Storage For A Hybrid Renewable Energy System, Kusum Lata Tharani, Ratna Dahiya

Turkish Journal of Electrical Engineering and Computer Sciences

There are certain unelectrified villages across the Indian subcontinent where providing supply through the grid is difficult due to forest cover or mountainous terrain. The most feasible option is to provide off-grid electrification through renewable energy resources such as solar or wind energy. These intermittent sources do not promise a 24 $\times $ 7 supply system. Thus, along with solar or wind energy systems, it becomes important to use a renewable resource, such as biomass, which is available in abundance in rural areas. The need for battery energy storage becomes mandatory in order to store the surplus energy produced by …


A Cutting-Plane Method For Contiguity-Constrained Spatial Aggregation, Johannes Oehrlein, Jan-Henrik Haunert Dec 2017

A Cutting-Plane Method For Contiguity-Constrained Spatial Aggregation, Johannes Oehrlein, Jan-Henrik Haunert

Journal of Spatial Information Science

Aggregating areas into larger regions is a common problem in spatial planning, geographic information science, and cartography. The aim can be to group administrative areal units into electoral districts or sales territories, in which case the problem is known as districting. In other cases, area aggregation is seen as a generalization or visualization task, which aims to reveal spatial patterns in geographic data. Despite these different motivations, the heart of the problem is the same: given a planar partition, one wants to aggregate several elements of this partition to regions. These often must have or exceed a particular size, be …


How To Best Apply Neural Networks In Geosciences: Towards Optimal "Averaging" In Dropout Training, Afshin Gholamy, Justin Parra, Vladik Kreinovich, Olac Fuentes, Elizabeth Y. Anthony Dec 2017

How To Best Apply Neural Networks In Geosciences: Towards Optimal "Averaging" In Dropout Training, Afshin Gholamy, Justin Parra, Vladik Kreinovich, Olac Fuentes, Elizabeth Y. Anthony

Departmental Technical Reports (CS)

The main objectives of geosciences is to find the current state of the Earth -- i.e., solve the corresponding inverse problems -- and to use this knowledge for predicting the future events, such as earthquakes and volcanic eruptions. In both inverse and prediction problems, often, machine learning techniques are very efficient, and at present, the most efficient machine learning technique is deep neural training. To speed up this training, the current learning algorithms use dropout techniques: they train several sub-networks on different portions of data, and then "average" the results. A natural idea is to use arithmetic mean for this …


Efficient Gate System Operations For A Multipurpose Port Using Simulation Optimization, Ketki Kulkarni, Trong Khiem Tran, Hai Wang, Hoong Chuin Lau Dec 2017

Efficient Gate System Operations For A Multipurpose Port Using Simulation Optimization, Ketki Kulkarni, Trong Khiem Tran, Hai Wang, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

Port capacity is determined by three major infrastructural resources namely, berths, yards and gates. Theadvertised capacity is constrained by the least of the capacities of the three resources. While a lot ofattention has been paid to optimizing berth and yard capacities, not much attention has been given toanalyzing the gate capacity. The gates are a key node between the land-side and sea-side operations in anocean-to-cities value chain. The gate system under consideration, located at an important port in an Asiancity, is a multi-class parallel queuing system with non-homogeneous Poisson arrivals. It is hard to obtaina closed form analytic approach for …


Optimizing Barrier Removal To Restore Connectivity In Utah’S Weber Basin, Maggi Kraft Dec 2017

Optimizing Barrier Removal To Restore Connectivity In Utah’S Weber Basin, Maggi Kraft

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

River barriers, such as dams, culverts and diversions are important for water conveyance, but disrupt river ecosystems and hydrologic processes. River barrier removal is increasingly used to restore and improve river habitat and connectivity. Most past barrier removal projects prioritized individual barriers using score-and-rank techniques, neglecting the spatial structure and cumulative change from multiple barrier removals. Similarly, most water demand models satisfy human water uses or, only prioritize aquatic habitat, failing to include both human and environmental water use benefits. In this study, a dual objective optimization model identified in-stream barriers that impede quality-weighted aquatic habitat connectivity for Bonneville cutthroat …


A Selective-Discrete Particle Swarm Optimization Algorithm For Solving A Class Of Orienteering Problems, Aldy Gunawan, Vincent F. Yu, Perwira Redi, Parida Jewpanya, Hoong Chuin Lau Dec 2017

A Selective-Discrete Particle Swarm Optimization Algorithm For Solving A Class Of Orienteering Problems, Aldy Gunawan, Vincent F. Yu, Perwira Redi, Parida Jewpanya, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

This study addresses a class of NP-hard problem called the Orienteering Problem (OP), which belongs to a well-known class of vehicle routing problems. In the OP, a set of nodes that associated with a location and a score is given. The time required to travel between each pair of nodes is known in advance. The total travel time is limited by a predetermined time budget. The objective is to select a subset of nodes to be visited that maximizes the total collected score within a path. The Team OP (TOP) is an extension of OP that incorporates multiple paths. Another …


Optimization And Control Of Agent-Based Models In Biology: A Perspective, G. An, B. G. Fitzpatrick, S. Christley, P. Federico, A. Kanarek, R. Miller Neilan, M. Oremland, R. Salinas, R. Laubeanbacher, S. Lenhart Aug 2017

Optimization And Control Of Agent-Based Models In Biology: A Perspective, G. An, B. G. Fitzpatrick, S. Christley, P. Federico, A. Kanarek, R. Miller Neilan, M. Oremland, R. Salinas, R. Laubeanbacher, S. Lenhart

Ben G. Fitzpatrick

Agent-based models (ABMs) have become an increasingly important mode of inquiry for the life sciences. They are particularly valuable for systems that are not understood well enough to build an equation-based model. These advantages, however, are counterbalanced by the difficulty of analyzing and using ABMs, due to the lack of the type of mathematical tools available for more traditional models, which leaves simulation as the primary approach. As models become large, simulation becomes challenging. This paper proposes a novel approach to two mathematical aspects of ABMs, optimization and control, and it presents a few first steps outlining how one might …