Matching Items (7)
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- All Subjects: blockchain
- All Subjects: Sentiment Analysis
- Creators: Yau, Stephen S.
- Creators: Nakamura, Mutsumi
Description
This paper details the specification and implementation of a single-machine blockchain simulator. It also includes a brief introduction on the history & underlying concepts of blockchain, with explanations on features such as decentralization, openness, trustlessness, and consensus. The introduction features a brief overview of public interest and current implementations of blockchain before stating potential use cases for blockchain simulation software. The paper then gives a brief literature review of blockchain's role, both as a disruptive technology and a foundational technology. The literature review also addresses the potential and difficulties regarding the use of blockchain in Internet of Things (IoT) networks, and also describes the limitations of blockchain in general regarding computational intensity, storage capacity, and network architecture. Next, the paper gives the specification for a generic blockchain structure, with summaries on the behaviors and purposes of transactions, blocks, nodes, miners, public & private key cryptography, signature validation, and hashing. Finally, the author gives an overview of their specific implementation of the blockchain using C/C++ and OpenSSL. The overview includes a brief description of all the classes and data structures involved in the implementation, including their function and behavior. While the implementation meets the requirements set forward in the specification, the results are more qualitative and intuitive, as time constraints did not allow for quantitative measurements of the network simulation. The paper concludes by discussing potential applications for the simulator, and the possibility for future hardware implementations of blockchain.
ContributorsRauschenbach, Timothy Rex (Author) / Vrudhula, Sarma (Thesis director) / Nakamura, Mutsumi (Committee member) / Computer Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Security requirements are at the heart of developing secure, invulnerable software. Without embedding security principles in the software development life cycle, the likelihood of producing insecure software increases, putting the consumers of that software at great risk. For large-scale software development, this problem is complicated as there may be hundreds or thousands of security requirements that need to be met, and it only worsens if the software development project is developed by a distributed development team. In this thesis, an approach is provided for software security requirement traceability for large-scale and complex software development projects being developed by distributed development teams. The approach utilizes blockchain technology to improve the automation of security requirement satisfaction and create a more transparent and trustworthy development environment for distributed development teams. The approach also introduces immutability, auditability, and non-repudiation into the security requirement traceability process. The approach is evaluated against existing software security requirement solutions.
ContributorsKulkarni, Adi Deepak (Author) / Yau, Stephen S. (Thesis advisor) / Banerjee, Ayan (Committee member) / Wang, Ruoyu (Committee member) / Baek, Jaejong (Committee member) / Arizona State University (Publisher)
Created2022
Description
Large organizations have multiple networks that are subject to attacks, which can be detected by continuous monitoring and analyzing the network traffic by Intrusion Detection Systems. Collaborative Intrusion Detection Systems (CIDS) are used for efficient detection of distributed attacks by having a global view of the traffic events in large networks. However, CIDS are vulnerable to internal attacks, and these internal attacks decrease the mutual trust among the nodes in CIDS required for sharing of critical and sensitive alert data in CIDS. Without the data sharing, the nodes of CIDS cannot collaborate efficiently to form a comprehensive view of events in the networks monitored to detect distributed attacks. The compromised nodes will further decrease the accuracy of CIDS by generating false positives and false negatives of the traffic event classifications. In this thesis, an approach based on a trust score system is presented to detect and suspend the compromised nodes in CIDS to improve the trust among the nodes for efficient collaboration. This trust score-based approach is implemented as a consensus model on a private blockchain because private blockchain has the features to address the accountability, integrity and privacy requirements of CIDS. In this approach, the trust scores of malicious nodes are decreased with every reported false negative or false positive of the traffic event classifications. When the trust scores of any node falls below a threshold, the node is identified as compromised and suspended. The approach is evaluated for the accuracy of identifying malicious nodes in CIDS.
ContributorsYenugunti, Chandralekha (Author) / Yau, Stephen S. (Thesis advisor) / Yang, Yezhou (Committee member) / Zou, Jia (Committee member) / Arizona State University (Publisher)
Created2020
Description
The coordination of developing various complex and large-scale projects using computers has been well established and is the so-called computer-supported cooperative work (CSCW). Collaborative software development consists of a group of teams working together to achieve a common goal for developing a high-quality, complex, and large-scale software system efficiently, and it requires common processes and communication channels among these teams. The common processes for coordination among software development teams can be handled by similar principles in CSCW. The development of complex and large-scale software becomes complicated due to the involvement of many software development teams. The development of such a software system can be largely improved by effective collaboration among the participating software development teams at both software components and system levels. The efficiency of developing software components depends on trusted coordination among the participating teams for sharing, processing, and managing information on various participating teams, which are often operating in a distributed environment. Participating teams may belong to the same organization or different organizations. Existing approaches to coordination in collaborative software development are based on using a centralized repository to store, process, and retrieve information on participating software development teams during the development. These approaches use a centralized authority, have a single point of failure, and restricted rights to own data and software. In this thesis, the generation of trusted coordination in collaborative software development using blockchain is studied, and an approach to achieving trusted cooperation for collaborative software development using blockchain is presented. The smart contracts are created in the blockchain to encode software specifications and acceptance criteria for the software results generated by participating teams. The blockchain used in the approach is a private blockchain because a private blockchain has the characteristics of providing non-repudiation, privacy, and integrity, which are required in trusted coordination of collaborative software development. This approach is implemented using Hyperledger, an open-source private blockchain. An example to illustrate the approach is also given.
ContributorsPatel, Jinal Sunilkumar (Author) / Yau, Stephen S. (Thesis advisor) / Bansal, Ajay (Committee member) / Zou, Jia (Committee member) / Arizona State University (Publisher)
Created2020
Description
Many researchers have seen the value blockchain can add to the field of voting and many protocols have been proposed to allow voting to be conducted in a way that takes advantage of blockchains distributed and immutable structure. While blockchains immutable structure can take the place of paper records in preventing tampering it by itself is insufficient to construct a trustworthy voting system with eligibility, privacy, verifiability, and fairness requirements. Many of the protocols which strive to keep voters votes confidential, but also allow for verifiability and eligibility requirements rely on either a blind signature provided by a central authority to provide compliance with these requirements or ring signatures to prove membership in the set of voters. A blind signature issued by a central authority introduces a potential vulnerability as it allows a corrupt central authority to pass a large number of forged ballots into the mix without any detection. Ring signatures on the other hand tend to be overly resource intensive to allow for practical usage in large voting sets. The research in this thesis focuses on improving the trustworthiness of electronic voting systems by providing possible ways of avoiding or detecting corrupt central authorities while still relying upon the benefits of efficiency the blind signature provides.
ContributorsAnderson, Brandon David (Author) / Yau, Stephen S. (Thesis advisor) / Dasgupta, Partha (Committee member) / Marchant, Gary (Committee member) / Arizona State University (Publisher)
Created2020
Description
Behavioral economics suggests that emotions can affect an individual’s decision making. Recent research on this idea’s application on large societies hints that there may exist some correlation or maybe even some causation relationship between public sentiment—at least what can be pulled from Twitter—and the movement of the stock market. One major result of consistent research on whether or not public sentiment can predict the movement of the stock market is that public sentiment, as a feature, is becoming more and more valid as a variable for stock-market-based machine learning models. While raw values typically serve as invaluable points of data, when training a model, many choose to “engineer” new features for their models—deriving rates of change or range values to improve model accuracy.
Since it doesn’t hurt to attempt to utilize feature extracted values to improve a model (if things don’t work out, one can always use their original features), the question may arise: how could the results of feature extraction on values such as sentiment affect a model’s ability to predict the movement of the stock market? This paper attempts to shine some light on to what the answer could be by deriving TextBlob sentiment values from Twitter data, and using Granger Causality Tests and logistic and linear regression to test if there exist a correlation or causation between the stock market and features extracted from public sentiment.
Since it doesn’t hurt to attempt to utilize feature extracted values to improve a model (if things don’t work out, one can always use their original features), the question may arise: how could the results of feature extraction on values such as sentiment affect a model’s ability to predict the movement of the stock market? This paper attempts to shine some light on to what the answer could be by deriving TextBlob sentiment values from Twitter data, and using Granger Causality Tests and logistic and linear regression to test if there exist a correlation or causation between the stock market and features extracted from public sentiment.
ContributorsYu, James (Author) / Meuth, Ryan (Thesis director) / Nakamura, Mutsumi (Committee member) / Computer Science and Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Machine learning is the process of training a computer with algorithms to learn from data and make informed predictions. In a world where large amounts of data are constantly collected, machine learning is an important tool to analyze this data to find patterns and learn useful information from it. Machine learning applications expand to numerous fields; however, I chose to focus on machine learning with a business perspective for this thesis, specifically e-commerce.
The e-commerce market utilizes information to target customers and drive business. More and more online services have become available, allowing consumers to make purchases and interact with an online system. For example, Amazon is one of the largest Internet-based retail companies. As people shop through this website, Amazon gathers huge amounts of data on its customers from personal information to shopping history to viewing history. After purchasing a product, the customer may leave reviews and give a rating based on their experience. Performing analytics on all of this data can provide insights into making more informed business and marketing decisions that can lead to business growth and also improve the customer experience.
For this thesis, I have trained binary classification models on a publicly available product review dataset from Amazon to predict whether a review has a positive or negative sentiment. The sentiment analysis process includes analyzing and encoding the human language, then extracting the sentiment from the resulting values. In the business world, sentiment analysis provides value by revealing insights into customer opinions and their behaviors. In this thesis, I will explain how to perform a sentiment analysis and analyze several different machine learning models. The algorithms for which I compared the results are KNN, Logistic Regression, Decision Trees, Random Forest, Naïve Bayes, Linear Support Vector Machines, and Support Vector Machines with an RBF kernel.
The e-commerce market utilizes information to target customers and drive business. More and more online services have become available, allowing consumers to make purchases and interact with an online system. For example, Amazon is one of the largest Internet-based retail companies. As people shop through this website, Amazon gathers huge amounts of data on its customers from personal information to shopping history to viewing history. After purchasing a product, the customer may leave reviews and give a rating based on their experience. Performing analytics on all of this data can provide insights into making more informed business and marketing decisions that can lead to business growth and also improve the customer experience.
For this thesis, I have trained binary classification models on a publicly available product review dataset from Amazon to predict whether a review has a positive or negative sentiment. The sentiment analysis process includes analyzing and encoding the human language, then extracting the sentiment from the resulting values. In the business world, sentiment analysis provides value by revealing insights into customer opinions and their behaviors. In this thesis, I will explain how to perform a sentiment analysis and analyze several different machine learning models. The algorithms for which I compared the results are KNN, Logistic Regression, Decision Trees, Random Forest, Naïve Bayes, Linear Support Vector Machines, and Support Vector Machines with an RBF kernel.
ContributorsMadaan, Shreya (Author) / Meuth, Ryan (Thesis director) / Nakamura, Mutsumi (Committee member) / Computer Science and Engineering Program (Contributor, Contributor) / Dean, W.P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05