Exploring Privacy Preservation in Outsourced K-Nearest Neighbors with Multiple Data Owners

The k-nearest neighbors (k-NN) algorithm is a popular and effective classification algorithm. Due to its large storage and computational requirements, it is suitable for cloud outsourcing. However, k-NN is often run on sensitive data such as medical records, user images, or personal information. It is important to protect the privacy of data in an outsourced k-NN system. Prior works have all assumed the data owners (who submit data to the outsourced k-NN system) are a single trusted party. However, we observe that in many practical scenarios, there may be multiple mutually distrusting data owners. In this work, we present the first framing and exploration of privacy preservation in an outsourced k-NN system with multiple data owners. We consider the various threat models introduced by this modification. We discover that under a particularly practical threat model that covers numerous scenarios, there exists a set of adaptive attacks that breach the data privacy of any exact k-NN system. The vulnerability is a result of the mathematical properties of k-NN and its output. Thus, we propose a privacy-preserving alternative system supporting kernel density estimation using a Gaussian kernel, a classification algorithm from the same family as k-NN. In many applications, this similar algorithm serves as a good substitute for k-NN. We additionally investigate solutions for other threat models, often through extensions on prior single data owner systems

Thermal Energy Storage for Load Shifting

The following document accounts for the progress made in the prototype development of our design solution since the Critical Design Review, and our group’s response to recent world events which greatly impacted planned activities. Our design challenge is to develop a thermal energy storage system which will sequester the energy from a photovoltaic (PV) array during the day and allow for its dispersal at night in the form of near boiling water. Looking at our user’s needs, we broke our design solution into four components: water heating, storage, distribution, and controls. Research of all components was conducted to ascertain which systems should be developed and which system components could be purchased. Engineering specifications were developed to directly address customer needs and to create performance goals which our final solution can be measured against. During this phase, our group was tasked with procuring all required materials, manufacturing our prototype, and conducting verification testing. The system configuration was selected in the previous phase, and lists of components were compiled, along with manufacturing steps. We have constructed our prototype, and we have completed some preliminary testing, however there is more work to be completed by our sponsor. The selected system composition is outlined, including supporting documentation for testing procedures. Our Final Design Review outlines all final development activities which have taken place and next steps required for further iteration of our prototype

ESSAYS ON CORPORATE INVESTMENT

This dissertation is comprised of three essays on corporate investment. The first essay, titled "What If the Firm Does Not Diversify? A Self-Selection Free Bayesian Approach", takes a comprehensive look at the diversification discount. By employing a switching regression model with the Bayesian data augmentation methodology, I compare the actual post-acquisition firm value of diversifying acquirers to the counter-factual alternative which is a non-diversifying acquisition. I find that there is a considerable amount of acquirers that could improve their value by diversifying acquisitions more than what they would improve by non-diversifying acquisitions. When there are negative shocks to the acquirers' primary industries, when these industries are concentrated and the firms are not dominant players in the industries, diversifying acquisitions add values to the firms. The firm-by-firm analysis shows that on average, no diversification discount exists. The next two essays study U.S. manufacturing firms' outsourcing activity, using a unique dataset of purchase obligations from firm 10-Ks. The second essay is titled "Outsourcing and Firm Financial Structure", and the third essay is titled "Firm Risk Taking versus CEO Diversification: Evidence from Outsourcing Firms". In the second essay, I explore the outsourcing decision and its implications on firm investment and capital structure. I first examine what kinds of firms use external contracts to provide a product or service as a major input to their production. I find that relatively young or large firms with a large number of patents are more likely to use external purchase contracts. Within high-technology industries, firms with purchase contracts tend to have higher R&D investment, while in low- technology industries, firms with purchase contracts are more likely to enter new markets. Outsourcing activity has important risk and capital structure implications, as firms that outsource have significantly less leverage. These results are consistent with outsourcing being used by firms to improve their flexibility. Faced with this increased firm flexibility and fewer fixed assets to pledge as collateral, outsourcing firms finance their operations proportionally more with equity. In the third essay, I examine CEO compensation in outsourcing firms. I find that the intensity of outsourcing can significantly explain the variations in CEO compensation; the more the firms do outsourcing, the more they pay to their CEOs. Outsourcing firms promote managerial risk-taking by using proportionally more equity-based compensation. However, they also need to compensate additionally their CEOs for the higher risk exposure to the firms' increased total risks. I show that outsourcing firms determine their compensation level and structure based on this optimal trade-off

A Practical Framework for Storing and Searching Encrypted Data on Cloud Storage

Security has become a significant concern with the increased popularity of cloud storage services. It comes with the vulnerability of being accessed by third parties. Security is one of the major hurdles in the cloud server for the user when the user data that reside in local storage is outsourced to the cloud. It has given rise to security concerns involved in data confidentiality even after the deletion of data from cloud storage. Though, it raises a serious problem when the encrypted data needs to be shared with more people than the data owner initially designated. However, searching on encrypted data is a fundamental issue in cloud storage. The method of searching over encrypted data represents a significant challenge in the cloud. Searchable encryption allows a cloud server to conduct a search over encrypted data on behalf of the data users without learning the underlying plaintexts. While many academic SE schemes show provable security, they usually expose some query information, making them less practical, weak in usability, and challenging to deploy. Also, sharing encrypted data with other authorized users must provide each document's secret key. However, this way has many limitations due to the difficulty of key management and distribution. We have designed the system using the existing cryptographic approaches, ensuring the search on encrypted data over the cloud. The primary focus of our proposed model is to ensure user privacy and security through a less computationally intensive, user-friendly system with a trusted third party entity. To demonstrate our proposed model, we have implemented a web application called CryptoSearch as an overlay system on top of a well-known cloud storage domain. It exhibits secure search on encrypted data with no compromise to the user-friendliness and the scheme's functional performance in real-world applications.Comment: 146 Pages, Master's Thesis, 6 Chapters, 96 Figures, 11 Table

Surf Sled

This Final Design Review document outlines the process by which we designed and built a surfboard sled, nicknamed the “Beachin’ Buggy”, for the AmpSurf program. The document describes the goals and services that AmpSurf provides for those living with disabilities, and the current methods that volunteers use to transport people from to beach to the water and onto a surfboard. It then identifies the need for a new system for beach-to-water transportation, along with all specifications, constraints, and goals for the system. Background research will be introduced to relate similar products to this project, and their relevant features and parameters will be detailed. The final design that has been chosen through a documented process will be presented, as well as the completed manufacturing. Finally, the yet to be completed aspects due to the coronavirus situation will be explained along with instructions to complete them

An overview of the European low-cost carrier (LCC) market : identifying sources of competitive advantage

This paper explores the low-cost carrier (LCC) reality in Europe by interrogating the main sources of competitive advantage and considering what major players should do to increase market share in the aftermath of the COVID-19 pandemic. By applying a standardized score methodology, this study took into account 25 variables to measure dimensions of competitive advantage and relative competitive positioning using published data sources from companies. The study further analyzed correlations between different indicators and confirmed strategies LCCs employ to maintain competitive positioning. Ryanair was considered the “lowest-cost carrier”, having the best competitive position in Europe, while WizzAir also displayed some promising indicators. easyJet exhibits indications that it is deviating from a pure low-cost model and employing strategies leaning towards a more hybrid business mode.Este artigo explora a realidade das companhias de baixo custo (LCC) na Europa, ao descobrir quais são as principais fontes de vantagem competitiva e ao considerar o que os principais players devem fazer para aumentar a quota de mercado no pós-pandemia da COVID-19. Ao aplicar uma metodologia de pontuação padronizada, este estudo levou em conta 25 variáveis para medir as dimensões da vantagem competitiva e o posicionamento competitivo, utilizando fontes de dados publicadas pelas empresas. O estudo ainda analisou as correlações entre os diferentes indicadores e confirmou as principais estratégias que as LCCs empregam para manter o seu posicionamento competitivo. A Ryanair foi considerada a "companhia de mais baixo custo" com a melhor posição competitiva na Europa, enquanto a WizzAir também apresentou alguns indicadores promissores. A easyJet apresenta indicações de que está a desviar-se de um modelo de low-cost puro e a adotar estratégias que se inclinam para um modelo de negócio mais híbrido

Small Spacecraft Thermal Control Louvers

Small satellites missions are becoming increasingly complex and are requiring more power. These demands lead to temperature fluctuations on the satellite due to spacecraft layout, sunlight and shadow in orbit, and high-powered instrumentation. Products which provide necessary thermal stability for components on the satellite are desirable to small satellite manufacturers. In September of 2015, Dr. Allison Evans of the NASA Goddard Space Flight Center filed a patent for an innovative louver system configured for small satellite applications. The design was sized for satellites with a 1U form factor and utilized bimetallic springs to lift the louver flaps. The design was licensed by Thermal Management Technologies, a company based in Logan, UT. While the louver system was intended for use in small satellites, a market in which TMT is an innovator, the design could not be integrated into the existing line of TMT products. The purpose of this project was to produce a passive thermal control system based on the licensed design that interfaces with existing TMT products. The system provides thermal stability without increasing power consumption through utilizing bimetallic springs to operate a louver system. The springs were calibrated to actuate between temperatures of -20˚C and +30˚C. The USU Thermal Louver Capstone Design Team created a modified design with a unified, iterable frame that aligns with the hole pattern of TMT’s existing radiator grid. The team conducted mechanical and thermal analysis on the design to determine that the device could perform within threshold values. The team fabricated a prototype of the unified design and conducted a series of tests to verify the analysis. The design proposed by the team is a more simple and robust design than the original version and can be mounted to TMT’s existing satellite radiator products. The prototype performed as expected and validated the team’s models