• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 400
  • 1
  • 1
  • Tagged with
  • 400
  • 400
  • 400
  • 400
  • 340
  • 128
  • 91
  • 91
  • 13
  • 6
  • 6
  • 6
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Breaking the thermo-mechanical coupling of thermoelectric materials : determining the viability of a thermoelectric generator / Determining the viability of a thermoelectric generator

Christian, Corey D.(Corey Dwight) January 2019 (has links)
Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, 2019 / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 69-70). / Thermoelectric power generators (TEGs) convert a temperature difference into electricity. This temperature difference can be created from waste heat. Since up to 50% [1] of US industrial energy input is lost as waste heat, an economical means of recovering waste heat and converting it into useful electricity could represent significant energy savings. Coupled with our integrative system design which involves creating application specific thermoelectric arrays, this technology can also help enable low power generation for off-grid needs in the developing world. Although conversion efficiencies as high as 20.9% [2] (heat to electrical energy) have been predicted from simulations of TEGs systems, in practice the efficiencies are typically only a few percent. Moreover, conventional systems often require expensive components to manage heat flow through the system. / As a result of the low efficiency and high system cost, electricity generated by thermoelectric energy harvesting from waste heat is currently not competitive with conventional electricity generation on a dollars-per-watt basis. This realization has led researchers to not only focus on increasing TEG device efficiency limits but to devise cheaper manufacturing processes and methods. A system design constraint that has not been fully investigated is the coupling of thermal and mechanical properties in thermoelectric materials. The extent to which this coupling affects the performance of the TEGs will be studied. This thesis develops an approach for decoupling the thermal and mechanical properties and tests it through a variety of simulations. We propose a mechanically compliant attachment strategy which could be integrated in various waste heat recovery applications. / The strategy involves breaking the thermal and mechanical bond formed by the brittle thermoelectric elements and its substrate. Copper wire, which is more pliable, is then used to connect the thermoelectric element to the substrate. A system analysis was performed for waste heat recovery from a vehicles exhaust pipe. We found that utilizing the proposed strategy should not only lead to increased mechanical compliance but can also lead to cost savings on a dollars-per-watt basis. We found that 84% power retention could be obtained when up to 16x less material is used under most apparent conditions¹. / by Corey D. Christian. / S.M. in Engineering and Management / S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program
2

Assessing digital transformation capabilities

Shah, Bahubali(Bahubali Pavankumar) January 2019 (has links)
Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, 2019 / Cataloged from PDF version of thesis. "February 2019." / Includes bibliographical references (pages 79-83). / It is widely believed that we are currently living in the digital age. Advances in technologies enabling connectivity, data aggregation and analysis, and aritificial intelligence/ machine learning are making it possible to obtain insights into human and machine behaviour like never before. Companies are rushing to take advantage of this new resource called data for competitive advantage. Yet, while many are aiming to pursue a Digital Transformation strategy within their organization, there appears to be a range of different opinions that professionals/ experts carry when it comes to identifying capabilities required to become a Digital Enterprise. This thesis is aimed at helping professionals in two ways. First, it identifies required capabilities at functional level from first principles. Second, it defines maturity levels for key generic capabilities at the company level for professionals to measure and guide their organization's progress towards becoming a Digital Enterprise. / by Bahubali Shah. / S.M. in Engineering and Management / S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program
3

Applying systems thinking towards countering hybrid warfare

Tan, Peihao Raymond. January 2019 (has links)
Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, 2019 / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 121-124). / Carl von Clausewitz, a famous Prussian general and military theorist asserted that war's nature of being violent, interactive, and fundamentally political, does not change - only its character does. According to Clausewitz, the character of war is a dynamic phenomenon that manifests differently with the "spirit" of each age. In our current digital age, technology has heavily influenced interactions, including warfare. In addition to boosting traditional military means, technology has enabled rapid and widespread weaponization of social, information and infrastructural instruments for political coercion. A rising trend of combining national instruments of power to wage war simultaneously across the political, military, economic, social, information and infrastructural domains is a rapidly emerging threat, characteristic of modem "hybrid wars" being fought today. Traditional military-centric defense policies and strategies are ill-prepared to address such threats that deliberately operate in the "grey zone", playing on ambiguity and tailoring coercion to remain just below detection and response thresholds. In this research, a combination of literature review, descriptive study, inductive approach, normative research, case study and systems thinking are applied to analyze the hybrid warfare threat and then construct a suitable response framework, treating it as system with interrelated constituent parts, synergistically working together over time, within the wider international context, to deliver an emergent counter hybrid warfare capability. / by Peihao Raymond Tan. / S.M. in Engineering and Management / S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program
4

Improving the innovation culture within the United States Coast Guard

Chien, Michael P. (Michael Pang-Chieh) January 2018 (has links)
Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, 2018. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / "September 2018." Cataloged from student-submitted PDF version of thesis. / Includes bibliographical references (pages 76-78). / It is increasingly difficult to maintain a technological edge within the United States Coast Guard. Technology continues to advance faster than it can be integrated into the organization. Unfortunately, Federal acquisition requirements and budgetary constraints also contribute to the lack of progress in technology adoption. This thesis explores the current state of innovation within the United States Department of Defense and the United States Coast Guard. In seeking to understand how to improve the culture of innovation within an organization, a review of literature was conducted and applicable key concepts presented. Principles of successful innovation were drawn from a sample of innovation centers within the DoD and Department of Homeland Security, and case studies used to scope innovation within the context of the Coast Guard. Finally, the author includes recommendations to increase innovation within the Coast Guard. This analysis provides a starting point to explore and map the ever-expanding innovation centers within the federal government, specifically in the Department of Defense and the Department of Homeland Security. / by Michael P. Chien. / S.M. in Engineering and Management
5

Whole human design : designing for Humans, not Users

Klein, Alex C.(Alex Charles) January 2018 (has links)
Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, 2018 / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 134-136). / In the past ten years, the Human-Centered Design methodology has exploded--permeating our organizational and academic worlds and becoming one of the most sought-after skills. The user-first mantra has become widely accepted and internalized. Develop empathy! Find users in their natural habitat! Design for their needs, not yours! Despite its vast popularity, I believe there is a great flaw and irony in the way we practice Human-Centered Design today: without the human. Though a human perceives his/her life as a dynamic whole (Gestalt Theory), we reduce him/her to a 'user', a shard of his/her full Self. This thesis explores the foundations of a new methodology, Whole Human Design[superscript TM], that seeks to re-unify the human and equip us to design for users in the context of their whole humanness. To that end, this thesis first seeks a usable definition of the Human and our human needs, by exploring a wide range of philosophical and psychological perspectives-from material/atomistic definitions (like those found in Behaviorism) to Phenomenology-inspired definitions (Existentialism, Humanistic Psychology, Positive Psychology) to Religious perspectives. From there, based on an ethnographic research with 50 individuals, this thesis introduces a design framework, the Periodic Table of Human Elements[superscript TM], a tool to connect functional and latent needs of a user to his/her deeper human roots. Finally, in order to illustrate how this methodology can be practiced, this thesis presents a case study of how Whole Human Design was used to solve a $300B real-world problem, medication adherence. / by Alex C. Klein. / S.M. in Engineering and Management / S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program
6

Development of a domestic space launch ecosystem for optimal support of US national interests

Reele, Maximilien H.(Maximilien Harry) January 2018 (has links)
Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, 2018 / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 120-125). / This thesis researches the current capabilities of the US Government's (USG) space launch portfolio and the processes in place to establish new-entrant launch providers for National Security Space payloads. It is hypothesized that there is an infeasibility of the current space launch enterprise to scale to satisfy increased demand. If true, the USG will be unable to meet projected launch requirements to satisfy nominal demand for NSS disaggregated constellations. Moreover, the USG will be unable to maintain space superiority in the aftermath of the eventual loss of NSS satellites due to adversary attacks and environmental events. A USG space launch enterprise system architecture analysis is conducted using a quantitative and qualitative approach that is designed to promote objectivity, resulting in a prioritized list of system requirements and primary stakeholders. / In turn, the results are used in generating goals and establishing an implementation strategy for any proposed changes to the system. In addition, the current state of the commercial space launch market is surveyed to gain an understanding for the existing and planned capabilities available in the commercial sector for potential transition into the USG space launch enterprise. Questions are posited on the relevance of funding and infrastructure investment for new-entrant space launch companies as well as on how current certification processes are impacting innovation in the industry. Investment and certification methods are further explored to determine if approaches can be generated that foster new-entrant participation, innovation, and competition through establishing fairness across the industry, setting performance targets, and removing barriers to entry for new market participants. / A System Dynamics model is built to represent the global space launch industry and serves as a testbed for the evaluation of current and future space launch performance. Data outputs from simulations validate the hypothesis that the current USG space launch enterprise is unable to scale capabilities to meet greater demand conditions. Simulations are also used to assess various combinations of proposed changes to the USG space launch enterprise in an effort to uncover areas for systematic improvements in key performance attributes. In order to 1) enable space superiority by offering greater resiliency and responsiveness through diversity of space launch capabilities, and 2) to stimulate industry competition, innovation, and learning by continuously refreshing the base of domestic launch providers, it is concluded and recommended that the USG adopt a series of investment, certification, and process proposals. / A call for future work to experiment with the recommended approaches is made in order to validate, improve upon, and refine implementation of a Domestic Space Launch Ecosystem. / by Maximilien H. Reele. / S.M. in Engineering and Management / S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program
7

Redesigning the United States Department of Education for localized ideation through user-centric research and organizational design

Reid, Tanner Scott. January 2019 (has links)
Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, 2019 / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 73-74). / Education inequality in the United States is a complex challenge to tackle, and one that a centralized enterprise isn't always equipped to address. The United States Department of Education has a mission to bring a quality, globally-competitive education to all students in the US, but leaves to the states much of the power to enact policy towards that end - the department itself recognizes that states are responsible for curriculum development, graduation standards, school facilities, standardized tests, community programs, and other factors that affect educational outcomes. While the federal Department of Education provides quantitative data collection and publishing, student loan programs, anti-discrimination mandates, and other initiatives vital to the management of education nationwide, compared to states, they are relatively distanced from the local issues that hugely impact end education experience. / This thesis proposes an enterprise-level transformation of the department, envisioning an organization that runs much like a design firm to perform localized, targeted, user-centric research to facilitate ideation and insight-sharing among states and like-communities across the country. To do this, a systems-analysis approach is employed to break down the current architecture, run stakeholder analysis, conceptualize a number of ideas meant to spark further ideation in the organizational-design space, evaluate those ideas, and develop one further. / A two-part organizational solution to foster localized ideation for states and communities is outlined: (1) a design-firm-like organization within the department that appoints two research fellows in each state to help connect state efforts to federal efforts while using these two fellows to build a qualitative database that can fill the gaps left with quantitative methods, and (2) a matrix research and development structure that combines the two groups into one organization that works across channels for rural, urban, and suburban insights and initiatives. The case is made that this is the best way to divide the organization (as opposed to geographic or functional organizations), due to the similarities in community structure and resources in each category. This exploration aims to prove that systemic actions (and not just specific policy proposals) can have a substantial impact on government innovation and social outcomes. / by Tanner Scott Reid. / S.M. in Engineering and Management / S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program
8

Application of STPA-Sec for analyzing cybersecurity of autonomous mining systems / Application of Systems-Theoretic Process Analysis for Security for analyzing cybersecurity of autonomous mining systems

Sidhu, Amardeep Singh. January 2019 (has links)
Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, 2019 / Cataloged from PDF version of thesis. "February 2019." / Includes bibliographical references (pages 107-110). / Autonomy is seen as the next big thing in the mining industry. For mine operators there are benefits to be gained in terms of higher productivity, inherent safety, lower operational expense, and improved asset management, just to name a few. Original equipment manufacturers (OEM) and dealerships also benefit by gaining the ability to better manage machine lifecycles, adding additional revenue streams from auxiliary products and services like mine operating system (MOS), training, and contracts to run mine autonomy and automation as a service. For this work, we have selected the autonomous haul truck used in the surface mining operation as the subject. We were motivated primarily by existing OEM efforts on introducing autonomy in the industry through hauling. Various stages of hauling process including the interaction with manually operated MOS and shovel were studied. / Systems-Theoretic Process Analysis for Security (STPA-Sec) method was applied to the loading subsystem of open pit surface mining, where the manually operated shovel and the autonomous haul truck interact. System level safety and cybersecurity hazards were identified, a functional control structure prepared, and a system state model developed. A control action of "autonomous-stop" from the shovel operator and directed towards the autonomous haul truck was analyzed to identify unsecure control actions and corresponding unsecure constraints. Extension to the STPA-Sec framework in the form of modified attack trees was applied to generate rich set of scenarios with the unsafe and unsecure control action as the attack goal. Cybersecurity requirements for the shovel and haul truck subsystem interaction were derived by analyzing scenarios and recommended mitigations. / Results indicated that the STPA-Sec with attack tree performs better than any single method from SAE J3061 based on the process, quality, and quantity of cyber-physical threats identified. In addition, STPA-Sec with attack tree filled an important gap by offering structure and traceability during scenario generation process of STPA. Future work could focus on automating STPA-Sec analysis steps where expert knowledge is not required and integrating the improved STPA-Sec as a hazard analysis and risk assessment framework under ISO26262. / by Amardeep Singh Sidhu. / S.M. in Engineering and Management / S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program
9

The Good Grains Project

Sharma, Nidhi,S.M.Massachusetts Institute of Technology. January 2019 (has links)
Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, 2019 / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 103-106). / Foodgrains (like wheat, peanuts, etc.) gain moisture when they are stored, which leads to variation in weight and deterioration in quality. These commodities are sold by weight in India, and therefore, variable weight directly impacts the economic value of the produce. In addition, the quality of foodgrains is tightly coupled to their moisture content. For instance, if the moisture content of wheat is higher than 12%, it is not purchased by the local agriculture markets at the market price. Such produce is either rejected (sent back to the farmer for drying) or purchased at a much lower (discounted) price owing to the quality depreciation because of high moisture content. The depreciation is due to the presence of unwanted moisture, which results in growth of fungi. Fungal interaction with foodgrains leads to formation of Aflatoxin, which is one of the most toxic and carcinogenic substances known. Current solutions for detecting aflatoxin or uncontrolled moisture are either time consuming and expensive lab tests, or inefficient mechanisms based on unreliable sampling, which are inaccessible to farmers, warehouse managers and consumers, and provide a poor generalisation of the grain quality at the best. I have attempted to develop an easy to use and low-cost product that helps detect the presence of uncontrolled moisture in foodgrains, which is closely correlated to the presence of Aflatoxin. The product comes in the form of a smart RFID sensor, embedded in each of the gunny bags that store commodities like wheat, rice, etc. While a usual RFID tag only detects the presence of an object, the innovation here lies in creating an RFID tag that also responds to the moisture content of the commodity in the bag. This product can be a path-breaking innovation for warehousing corporations in India, as it will help keep a track of quality of millions of tonnes of food commodities, at a much deeper level in the supply chain. / by Nidhi Sharma. / S.M. in Engineering and Management / S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program
10

Flexible options in semiconductor design

McShea, Matthew D. January 2019 (has links)
Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, 2019 / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 79-82). / In semiconductor design, system architects must find the right balance between competing goals [1]: 1. Creating customer value with low average development costs to minimize overhead over a range of products. 2. Fulfilling customer demand with the lowest per unit cost to maximize profit. 3. Exceeding customer expectations to increase market opportunity and drive future growth. As the cost for semiconductor development and investment increases, so does the uncertainty of market success for new products. In this risky environment, a flexible design that increases market opportunity is potentially highly valuable. Flexible designs allow system architects to defer decisions about the exact system configuration and functionality which in turn minimizes the downside effects associated with unforeseen changes in market demand and promotes learning opportunities which lower per unit cost over time [2]. / In semiconductors, monolithic designs built for a single, specific application, often have lower overall manufacturing cost when compared with discrete, general-purpose designs built to handle multiple applications. This thesis focuses on two dimensions of how flexible designs in semiconductors can meet changing requirements: modularity and generality. Modularity is when we can quickly re-configure elements in a system. Generality is when a single element in the system accommodates changing requirements. When carefully applied to semiconductor design, these flexibilities can provide higher overall value across all possible project outcomes when compared with single application, monolithic designs. The thesis presents a case study describing potential applications of flexible design techniques for semiconductor products. / A Net Present Value (NPV) analytical model calculated the expected return on investment for flexible designs combining multiple, smaller dies in a System in Package (SiP) integration. Its goal is to show how proper recognition of uncertainty and the time value of money, generally counter-balances, and sometimes overwhelm the economy of scale benefits from monolithic designs. Ultimately, this case study demonstrates the economic potential of flexible designs of semiconductor products. / by Matthew D. McShea. / S.M. in Engineering and Management / S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program

Page generated in 0.1854 seconds