Engineering Commons^™

An Empirical Comparison Of The Security And Performance Characteristics Of Topology Formation Algorithms For Bitcoin Networks, Muntadher Sallal, Ruairí De Fréin, Ali Malik, Benjamin Aziz

Articles

There is an increasing demand for digital crypto-currencies to be more secure and robust to meet the following business requirements: (1) low transaction fees and (2) the privacy of users. Nowadays, Bitcoin is gaining traction and wide adoption. Many well-known businesses have begun accepting bitcoins as a means of making financial payments. However, the susceptibility of Bitcoin networks to information propagation delay, increases the vulnerability to attack of the Bitcoin network, and decreases its throughput performance. This paper introduces and critically analyses new network clustering methods, named Locality Based Clustering (LBC), Ping Time Based Approach (PTBC), Super Node Based Clustering …

Faster Multidimensional Data Queries On Infrastructure Monitoring Systems, Yinghua Qin, Gheorghi Guzun

Faculty Research, Scholarly, and Creative Activity

The analytics in online performance monitoring systems have often been limited due to the query performance of large scale multidimensional data. In this paper, we introduce a faster query approach using the bit-sliced index (BSI). Our study covers multidimensional grouping and preference top-k queries with the BSI, algorithms design, time complexity evaluation, and the query time comparison on a real-time production performance monitoring system. Our research work extended the BSI algorithms to cover attributes filtering and multidimensional grouping. We evaluated the query time with the single attribute, multiple attributes, feature filtering, and multidimensional grouping. To compare with the existing prior …

An Investigation Into Cognitive Radio System Performance, Courtney Hardy, Lucas F. Feather, William S. Guy

Honors Theses

The objective of this thesis is to explore cognitive radio performance through an in-depth literature review and an implementation of a software-defined radio prototyping system. Specifically, this thesis investigates the spectrum-sensing aspect of cognitive radio by comparing two spectrum-sensing methods. It was found in the literature review that a system utilizing matched filter detection would provide higher probability of detection in low signal-to-noise ratio environments when compared to a system utilizing energy detection. These spectrum sensing methods were thus implemented and compared in the cognitive radio systems presented in this thesis. Additionally, experiments were conducted to determine the most efficient …

Endoscopic Targeting Tasks Simulator: An Approach Using Game Engines, Shaun W. Carnegie

Electronic Thesis and Dissertation Repository

The pervasiveness of simulators used in professions requiring the skilled control of expensive machinery such as is the case in the aviation, mining, construction, and naval industries raises an intriguing question about the relatively poor adoption within the field of medicine. Certain surgical procedures such as neuro-endoscopic and laparoscopic lend themselves well to the application of virtual reality based simulators. This is due to the innate ability to decom- pose these complex macro level procedures into a hierarchy of subtasks that can be modelled in a software simulator to augment existing teaching and training techniques.

The research in this thesis …

Link Scheduling In Multi-Transmit-Receive Wireless Networks, Hong-Ning Dai, Soung Chang Liew, Liqun Fu

Hong-Ning Dai

This paper investigates the problem of link scheduling to meet traffic demands with minimum airtime in a multitransmit-receive (MTR) wireless network. MTR networks are a new class of networks, in which each node can simultaneously transmit to a number of other nodes, or simultaneously receive from a number of other nodes. The MTR capability can be enabled by the use of multiple directional antennas or multiple channels. Potentially, MTR can boost the network capacity significantly. However, link scheduling that makes full use of the MTR capability must be in place before this can happen. We show that optimal link scheduling …

On Collision-Tolerant Transmission With Directional Antennas, Hong-Ning Dai, Kam-Wing Ng, Min-You Wu

Hong-Ning Dai

The application of directional antennas in wireless networks brings numerous benefits, such as increased spatial reuse and mitigated interferences. Most MAC protocols with directional antennas are based on the RTS/CTS mechanism which works well in wireless networks using omni-directional antennas. However, RTS/CTS frames cannot mitigate the interfering nodes completely. Besides, they also contribute a lot to the performance overhead. This paper studies the problem from a new perspective. We analyze the transmission success probability under directional transmission and directional reception when the antenna beamwidth is quite narrow. Motivated by the analytical results, we design a lightweight MAC protocol without RTS/CTS …

On The Capacity Of Multi-Channel Wireless Networks Using Directional Antennas, Hong-Ning Dai, Kam-Wing Ng, Raymond Chi-Wing Wong, Min-You Wu

Hong-Ning Dai

The capacity of wireless ad hoc networks is affected by two key factors: the interference among concurrent transmissions and the number of simultaneous transmissions on a single interface. Recent studies found that using multiple channels can separate concurrent transmissions and greatly improve network throughput. However, those studies only consider that wireless nodes are equipped with only omnidirectional antennas, which cause high collisions. On the other hand, some researchers found that directional antennas bring more benefits such as reduced interference and increased spatial reuse compared with omnidirectional antennas. But, they only focused on a single-channel network which only allows finite concurrent …

Clarifying The Role Of Self-Efficacy And Metacognition As Indicators Of Learning: Construct Development And Test, Trevor T. Moores, Jerry Cha-Jan Chang, Deborah K. Smith

Management, Entrepreneurship and Technology Faculty Publications

We propose extending our understanding of self-efficacy by comparing self-efficacy with a related construct called metacognition. Metacognition involves the monitoring and control of one's thought processes and is often related, as is self-efficacy, to performance on a task. We develop an instrument that attempts to measure both self-efficacy and metacognition with respect to one's performance on a test covering declarative and procedural knowledge (knowing that, and knowing how) of DFDs and ERDs. With data collected from a sample of 124 students, we use partial least squares (PLS) to show that self-efficacy and metacognition are distinct yet related constructs. While self-efficacy …