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Full-Text Articles in Computer Engineering

A Comparative Study Of Generalized Arc-Consistency Algorithms, Olufikayo S. Adetunji Dec 2014

A Comparative Study Of Generalized Arc-Consistency Algorithms, Olufikayo S. Adetunji

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

In this thesis, we study several algorithms for enforcing Generalized Arc­-Consistency (GAC), which is the most popular consistency property for solving Constraint Satisfaction Problems (CSPs) with backtrack search. The popularity of such algorithms stems from their relative low cost and effectiveness in improving the performance of search. Virtually all commercial and public- domain constraint solvers include some implementation of a generic GAC algorithm. In recent years, several algorithms for enforcing GAC have been proposed in the literature that relies on increasingly complex data structures and mechanisms to improve performance. In this thesis, we study, assess, and compare a basic ...


A Comparative Study Of Underwater Robot Path Planning Algorithms For Adaptive Sampling In A Network Of Sensors, Sreeja Banerjee Aug 2014

A Comparative Study Of Underwater Robot Path Planning Algorithms For Adaptive Sampling In A Network Of Sensors, Sreeja Banerjee

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

Monitoring lakes, rivers, and oceans is critical to improving our understanding of complex large-scale ecosystems. We introduce a method of underwater monitoring using semi-mobile underwater sensor networks and mobile underwater robots in this thesis. The underwater robots can move freely in all dimension while the sensor nodes are anchored to the bottom of the water column and can move only up and down along the depth of the water column. We develop three different algorithms to optimize the path of the underwater robot and the positions of the sensors to improve the overall quality of sensing of an area of ...


A Methodology And Tool For Concurrent Fault Injection, Zhongyin Zhang Jul 2014

A Methodology And Tool For Concurrent Fault Injection, Zhongyin Zhang

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

As the speed of microprocessors tails off, utilizing multiple processing cores per chip is becoming a common way for developers to achieve higher performance. However, writing concurrent programs can be a big challenge because of common concurrency faults. Because concurrency faults are hard to detect and reproduce, traditional testing techniques are not suitable. New techniques are needed, and these must be assessed. A typical method for assessing testing techniques is to embed faults in programs using mutation tools, and assess the ability of techniques to detect these. Although mutation testing techniques can be used to represent common faults, approaches for ...


Measuring Autonomy And Solving General Stabilization Problems With Multi-Agent Systems, Rasheed A. Rajabzadeh Jul 2014

Measuring Autonomy And Solving General Stabilization Problems With Multi-Agent Systems, Rasheed A. Rajabzadeh

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

Many distributed complex problems address a particular form of resource scheduling where proper resource management can cut costs by stabilizing a set of stochastic fluctuating parameters. Wireless sensor network communication, supply chain management, stock trading, intelligent traffic management, and smart grid systems are examples of these problems. Among the various solutions, a common strategy often used to address this type of problems is fluctuation reduction via resource buffering combined with load shifting. Respectively, stable wireless communication, demand for supplies, liquidity, traffic speed, and power demand reduce cost and can be achieved by properly managing sensor data buffers, warehouses, capital, distance ...


Invariant Inferring And Monitoring In Robotic Systems, Hengle Jiang Jul 2014

Invariant Inferring And Monitoring In Robotic Systems, Hengle Jiang

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

System monitoring can help to detect abnormalities and avoid failures. Crafting monitors for today’s robotic systems, however, can be very difficult due to the systems’ inherent complexity and its rich operating environment.

In this work we address this challenge through an approach that automatically infers system invariants and synthesizes those invariants into monitors. This approach is inspired by existing software engineering approaches for automated invariant inference, and it is novel in that it derives invariants by observing the messages passed between system nodes and the invariants types are tailored to match the spatial, time, temporal, and architectural attributes of ...


Power Management In The Cluster System, Leping Wang Jun 2014

Power Management In The Cluster System, Leping Wang

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

With growing cost of electricity, the power management of server clusters has become an important problem. However, most previous researchers have only addressed the challenge in traditional homogeneous environments. Considering the increasing popularity of heterogeneous and virtualized systems, this thesis develops a series of efficient algorithms respectively for power management of heterogeneous soft real-time clusters and a virtualized cluster system. It is built on simple but effective mathematical models. When deployed to a new platform, the software incurs low configuration cost because no extensive performance measurements and profiling are required. Built upon optimization, queuing theory and control theory techniques, our ...


Decaf: A New Event Detection Logic For The Purpose Of Fusing Delineated-Continuous Spatial Information, Kerry Q. Hart May 2014

Decaf: A New Event Detection Logic For The Purpose Of Fusing Delineated-Continuous Spatial Information, Kerry Q. Hart

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

Geospatial information fusion is the process of synthesizing information from complementary data sources located at different points in space and time. Spatial phenomena are often measured at discrete locations by sensor networks, technicians, and volunteers; yet decisions often require information about locations where direct measurements do not exist. Traditional methods assume the spatial phenomena to be either discrete or continuous, an assumption that underlies and informs all subsequent analysis. Yet certain phenomena defy this dichotomy, alternating as they move across spatial and temporal scales. Precipitation, for example, appears continuous at large scales, but it can be temporally decomposed into discrete ...


Using A Uav To Effectively Prolong Wireless Sensor Network Lifetime With Wireless Power Transfer, Jinfu Leng May 2014

Using A Uav To Effectively Prolong Wireless Sensor Network Lifetime With Wireless Power Transfer, Jinfu Leng

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

Wireless sensor networks are widely used for everything from border security to monitoring waterway pollution. Supplying energy for long term deployment is a main challenge in the applications of wireless sensor networks, as batteries are the primary energy source. Current wireless sensor networks deployed for long periods either require additional infrastructure, such as solar panels, or periodic maintenance. Our research lab has proposed a novel solution that uses a micro unmanned aerial vehicle (UAV) to wirelessly charge the sensor nodes and prolong the sensor network lifetime. Recent studies have shown that significant power can be transferred wirelessly over medium distances ...


Dnn: A Distributed Namenode Filesystem For Hadoop, Ziling Huang May 2014

Dnn: A Distributed Namenode Filesystem For Hadoop, Ziling Huang

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

The Hadoop Distributed File System (HDFS) is the distributed storage infrastructure for the Hadoop big-data analytics ecosystem. A single node, called the NameNode of HDFS stores the metadata of the entire file system and coordinates the file content placement and retrieval actions of the data storage subsystems, called DataNodes. However the single NameNode architecture has long been viewed as the Achilles' heel of the Hadoop Distributed file system, as it not only represents a single point of failure, but also limits the scalability of the storage tier in the system stack. Since Hadoop is now being deployed at increasing scale ...


Analysis, Optimization, And Implementation Of A Uav-Based Wireless Power Transfer System, Andrew Mittleider May 2014

Analysis, Optimization, And Implementation Of A Uav-Based Wireless Power Transfer System, Andrew Mittleider

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

Wireless power transfer is rapidly advancing in its ability to efficiently transfer power to a variety of devices.

As the efficiency increases, more applications for these systems arise. Since magnetic resonant wireless power transfer can only transfer a small amount of power, most current applications only focus on powering low-powered devices.

Wireless Sensor Networks are composed of many low-powered nodes which currently require human interaction to remain powered. We propose recharging a low-powered Wireless Sensor Network (WSN) with a magnetic resonant wireless power transfer system attached to a quadrotor Unmanned Aerial Vehicle (UAV).

This thesis addresses three main challenges with ...


A New Spatio-Temporal Data Mining Method And Its Application To Reservoir System Operation, Abhinaya Mohan Apr 2014

A New Spatio-Temporal Data Mining Method And Its Application To Reservoir System Operation, Abhinaya Mohan

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

This thesis develops a spatio-temporal data mining method for uncertain water reservoir data. The goal of the data mining method is to learn from a history human reservoir operations in order to derive an automated controller for a reservoir system. Spatio-temporal data mining is a challenging task due to the reasons: (1) spatio-temporal datasets are usually much larger than spatial data sets, (2) many common spatial techniques are unable to deal with objects that change location, size or shape, and (3) complex and often non-linear spatio-temporal relationships cannot be separated into pure spatial and pure temporal relationships.

Support Vector Machines ...


Autonomous Aerial Water Sampling, John-Paul W. Ore Apr 2014

Autonomous Aerial Water Sampling, John-Paul W. Ore

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

Obtaining spatially separated, high frequency water samples from rivers and lakes is critical to enhance our understanding and effective management of fresh water resources. In this thesis we present an aerial water sampler and verify the system in field experiments. The aerial water sampler has the potential to vastly increase the speed and range at which scientists obtain water samples while reducing cost and effort. The water sampling system includes: 1) a mechanism to capture three 20 ml samples per mission; 2) sensors and algorithms for safe navigation and altitude approximation over water; and 3) software components that integrate and ...