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Articles 1 - 17 of 17

Full-Text Articles in Other Computer Engineering

Power Laws In Complex Graphs: Parsimonious Generative Models, Similarity Testing Algorithms, And The Origins, Shan Lu Jan 2018

Power Laws In Complex Graphs: Parsimonious Generative Models, Similarity Testing Algorithms, And The Origins, Shan Lu

Doctoral Dissertations

This dissertation mainly discussed topics related to power law graphs, including graph similarity testing algorithms and power law generative models.

For graph similarity testing, we proposed a method based on the mathematical theory of diffusion over manifolds using random walks over graphs. We show that our method not only distinguishes between graphs with different degree distributions, but also graphs with the same degree distributions. We compare the undirected power law graphs generated by Barabasi-Albert model and directed power law graphs generated by Krapivsky's model to the random graphs generated by Erdos-Renyi model. We also compare power law graphs generated ...


Transiency-Driven Resource Management For Cloud Computing Platforms, Prateek Sharma Jan 2018

Transiency-Driven Resource Management For Cloud Computing Platforms, Prateek Sharma

Doctoral Dissertations

Modern distributed server applications are hosted on enterprise or cloud data centers that provide computing, storage, and networking capabilities to these applications. These applications are built using the implicit assumption that the underlying servers will be stable and normally available, barring for occasional faults. In many emerging scenarios, however, data centers and clouds only provide transient, rather than continuous, availability of their servers. Transiency in modern distributed systems arises in many contexts, such as green data centers powered using renewable intermittent sources, and cloud platforms that provide lower-cost transient servers which can be unilaterally revoked by the cloud operator.

Transient ...


Virtualization Of Closed-Loop Sensor Networks, Priyanka Dattatri Kedalagudde Jan 2017

Virtualization Of Closed-Loop Sensor Networks, Priyanka Dattatri Kedalagudde

Masters Theses

The existing closed-loop sensor networks are based on architectures that are designed and implemented for one specific application and require dedicated sensing and computational resources. This prevents the sharing of these networks. In this work, we propose an architecture of virtualization to allow sharing of closed-loop sensor networks. We also propose a scheduling approach that will manage requests from competing applications and evaluate their impact on system utilization against utilization achieved by more traditional, dedicated sensor networks. These algorithms are evaluated through trace-driven simulations, where the trace data is taken from CASA’s closed-loop weather radar sensor network. Results from ...


Query On Knowledge Graphs With Hierarchical Relationships, Kaihua Liu Jan 2017

Query On Knowledge Graphs With Hierarchical Relationships, Kaihua Liu

Masters Theses

The dramatic popularity of graph database has resulted in a growing interest in graph queries. Two major topics are included in graph queries. One is based on structural relationship to find meaningful results, such as subgraph pattern match and shortest-path query. The other one focuses on semantic-based query to find question answering from knowledge bases. However, most of these queries take knowledge graphs as flat forms and use only normal relationship to mine these graphs, which may lead to mistakes in the query results. In this thesis, we find hierarchical relationship in the knowledge on their semantic relations and make ...


Navigation Instruction Validation Tool And Indoor Wayfinding Training System For People With Disabilities, Linlin Ding Jan 2017

Navigation Instruction Validation Tool And Indoor Wayfinding Training System For People With Disabilities, Linlin Ding

Masters Theses

According to World Health Survey, there are 785 million (15.6%) people in the world that live with a disability. It is a well-known fact that lack of access to public transportation is a barrier for people with disabilities in seeking work or accessing health care. In this research, we seek to increase access to public transportation by introducing a virtual pre-travel training system that enables people with disabilities to get familiar with a public transportation venue prior to arriving at the venue. Using this system, users establish a mental map of the target environment prior to their arrival to ...


Explorations Into Machine Learning Techniques For Precipitation Nowcasting, Aditya Nagarajan Jan 2017

Explorations Into Machine Learning Techniques For Precipitation Nowcasting, Aditya Nagarajan

Masters Theses

Recent advances in cloud-based big-data technologies now makes data driven solutions feasible for increasing numbers of scientific computing applications. One such data driven solution approach is machine learning where patterns in large data sets are brought to the surface by finding complex mathematical relationships within the data. Nowcasting or short-term prediction of rainfall in a given region is an important problem in meteorology. In this thesis we explore the nowcasting problem through a data driven approach by formulating it as a machine learning problem.

State-of-the-art nowcasting systems today are based on numerical models which describe the physical processes leading to ...


Image Processing And Understanding Based On Graph Similarity Testing: Algorithm Design And Software Development, Jieqi Kang Jan 2017

Image Processing And Understanding Based On Graph Similarity Testing: Algorithm Design And Software Development, Jieqi Kang

Doctoral Dissertations

Image processing and understanding is a key task in the human visual system. Among all related topics, content based image retrieval and classification is the most typical and important problem. Successful image retrieval/classification models require an effective fundamental step of image representation and feature extraction. While traditional methods are not capable of capturing all structural information on the image, using graph to represent the image is not only biologically plausible but also has certain advantages.

Graphs have been widely used in image related applications. Traditional graph-based image analysis models include pixel-based graph-cut techniques for image segmentation, low-level and high-level ...


Spotlight: An Information Service For The Cloud, Xue Ouyang Jan 2016

Spotlight: An Information Service For The Cloud, Xue Ouyang

Masters Theses

Infrastructure-as-a-Service cloud platforms are incredibly complex: they rent hundreds of different types of servers across multiple geographical regions under a wide range of contract types that offer varying tradeoffs between risk and cost. Unfortunately, the internal dynamics of cloud platforms are opaque in several dimensions. For example, while the risk of servers not being available when requested is critical in optimizing these risk-cost tradeoffs, it is not typically made visible to users. Thus, inspired by prior work on Internet bandwidth probing, we propose actively probing cloud platforms to explicitly learn such information, where each "probe'' is a request for a ...


Function Verification Of Combinational Arithmetic Circuits, Duo Liu Jan 2015

Function Verification Of Combinational Arithmetic Circuits, Duo Liu

Masters Theses

Hardware design verification is the most challenging part in overall hardware design process. It is because design size and complexity are growing very fast while the requirement for performance is ever higher. Conventional simulation-based verification method cannot keep up with the rapid increase in the design size, since it is impossible to exhaustively test all input vectors of a complex design. An important part of hardware verification is combinational arithmetic circuit verification. It draws a lot of attention because flattening the design into bit-level, known as the bit-blasting problem, hinders the efficiency of many current formal techniques. The goal of ...


Indoor And Outdoor Real Time Information Collection In Disaster Scenario, Dongyi Yang Jan 2015

Indoor And Outdoor Real Time Information Collection In Disaster Scenario, Dongyi Yang

Masters Theses

A disaster usually severely harms human health and property. After a disaster, great amount of information of a disaster area is needed urgently. The information not only indicates the severity of the disaster, but also is crucial for an efficient search and rescue process. In order to quickly and accurately collect real time information in a disaster scenario, a mobile platform is developed for an outdoor scenario and a localization and navigation system for responders is introduced for an indoor scenario.

The mobile platform has been integrated to the DIORAMA system. It is built with a 6-wheel robot chassis along ...


Physically Equivalent Intelligent Systems For Reasoning Under Uncertainty At Nanoscale, Santosh Khasanvis Jan 2015

Physically Equivalent Intelligent Systems For Reasoning Under Uncertainty At Nanoscale, Santosh Khasanvis

Doctoral Dissertations

Machines today lack the inherent ability to reason and make decisions, or operate in the presence of uncertainty. Machine-learning methods such as Bayesian Networks (BNs) are widely acknowledged for their ability to uncover relationships and generate causal models for complex interactions. However, their massive computational requirement, when implemented on conventional computers, hinders their usefulness in many critical problem areas e.g., genetic basis of diseases, macro finance, text classification, environment monitoring, etc. We propose a new non-von Neumann technology framework purposefully architected across all layers for solving these problems efficiently through physical equivalence, enabled by emerging nanotechnology. The architecture builds ...


Application Of Techniques For Map Estimation To Distributed Constraint Optimization Problem, Yoonheui Kim Jan 2015

Application Of Techniques For Map Estimation To Distributed Constraint Optimization Problem, Yoonheui Kim

Doctoral Dissertations

The problem of efficiently finding near-optimal decisions in multi-agent systems has become increasingly important because of the growing number of multi-agent applications with large numbers of agents operating in real-world environments. In these systems, agents are often subject to tight resource constraints and agents have only local views. When agents have non-global constraints, each of which is independent, the problem can be formalized as a distributed constraint optimization problem (DCOP). The DCOP is closely associated with the problem of inference on graphical models. Many approaches from inference literature have been adopted to solve DCOPs. We focus on the Max-Sum algorithm ...


Integrating Non-Topical Aspects Into Information Retrieval, Elif Aktolga May 2014

Integrating Non-Topical Aspects Into Information Retrieval, Elif Aktolga

Doctoral Dissertations

When users investigate a topic, they are often interested in results that are not just relevant, but also strongly opinionated or covering a range of times. To get such results, users are forced to formulate ambiguous, complex, or longer queries. Commonly this becomes a burden, since users need to issue several queries with reformulations if initial search results are not completely satisfactory. In this thesis, we focus on those two non-topical dimensions: opinionatedness and time. We develop measures for quantifying them in documents and incorporate them into search results.

For improving search results with respect to non-topical dimensions, we use ...


Scheduling Heuristics For Maximizing The Output Quality Of Iris Task Graphs In Multiprocessor Environment With Time And Energy Bounds, Rajeswaran Chockalingapuram Ravindran Jan 2012

Scheduling Heuristics For Maximizing The Output Quality Of Iris Task Graphs In Multiprocessor Environment With Time And Energy Bounds, Rajeswaran Chockalingapuram Ravindran

Masters Theses 1911 - February 2014

Embedded real time applications are often subject to time and energy constraints. Real time applications are usually characterized by logically separable set of tasks with precedence constraints. The computational effort behind each of the task in the system is responsible for a physical functionality of the embedded system. In this work we mainly define theoretical models for relating the quality of the physical func- tionality to the computational load of the tasks and develop optimization problems to maximize the quality of the system subject to various constraints like time and energy. Specifically, the novelties in this work are three fold ...


Leveraging Multi-Radio Communication For Mobile Wireless Sensor Networks, Jeremy J. Gummeson Jan 2011

Leveraging Multi-Radio Communication For Mobile Wireless Sensor Networks, Jeremy J. Gummeson

Masters Theses 1911 - February 2014

An important challenge in mobile sensor networks is to enable energy-efficient communication over a diversity of distances while being robust to wireless effects caused by node mobility. In this thesis, we argue that the pairing of two complementary radios with heterogeneous range characteristics enables greater range and interference diversity at lower energy cost than a single radio. We make three contributions towards the design of such multi-radio mobile sensor systems. First, we present the design of a novel reinforcement learning-based link layer algorithm that continually learns channel characteristics and dynamically decides when to switch between radios. Second, we describe a ...


Evaluating A New Mac For Current And Next Generation Rfid, Serge Zhilyaev Jan 2010

Evaluating A New Mac For Current And Next Generation Rfid, Serge Zhilyaev

Masters Theses 1911 - February 2014

We evaluate SQUASH, a new MAC for RFID, in hardware and software. A smaller hardware design for SQUASH is proposed which also reduces latency. Area and latency in hardware are reduced further with a new variant we call permuted SQUASH. We explore SQUASH on embedded microprocessors and propose a method to choose the optimal partial product ordering to reduce latency.


Implementation Of Data Path Credentials For High-Performance Capabilities-Based Networks, Kamlesh T. Vasudevan Jan 2009

Implementation Of Data Path Credentials For High-Performance Capabilities-Based Networks, Kamlesh T. Vasudevan

Masters Theses 1911 - February 2014

Capabilities-based networks present a fundamental shift in the security design of network architectures. Instead of permitting the transmission of packets from any source to any destination, routers deny forwarding by default. For a successful transmission, packets need to positively identify themselves and their permissions to the router. A major challenge for a high performance implementation of such a network is an efficient design of the credentials that are carried in the packet and the verification procedure on the router. A network protocol that implements data path credentials based on Bloom filters is presented in this thesis. Our prototype implementation shows ...