Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, September, 2020 / Cataloged from the official version of thesis. / Includes bibliographical references (pages 56-57). / Understanding the factors that influence consumer investment in fuel economy when purchasing a new vehicle is critical for stakeholders including environmental policy makers, automotive manufacturers and oil companies. The energy economics literature shows that consumers are relatively rational in how much fuel economy they purchase in response to changes in gas price. Yet the marketing literature suggests that consumers only consider a small number of vehicle makes/models - as few as 2-6 - when making their purchase decision. Given this, we consider the extent to which consumer's rational response to gas price changes is achieved by including different vehicles in their consideration set, versus choosing differently from within their consideration set. We analyze data from 210,885 responses to a new vehicle customer satisfaction survey collected over 9 years in which respondents state the vehicles they considered purchasing in addition to the vehicle they ultimately purchased. Our findings show that as gasoline prices rise, their purchased vehicle fuel economy increases more than their consideration set average fuel economy does, with both increasing. This is the result of considering more fuel-efficient vehicles and also purchasing higher within their consideration set fuel economy range. The degree to which the consumer adjusts is shown to correspond to the importance they place on the environment during their shopping process. Increased consideration and adoption of alternative fuel vehicles are found to be one mechanism the consumer uses to make these adjustments. Finally, we highlight how changing gasoline prices result in differing consideration set behavior for buyers of low and high fuel economy vehicles. / by James D. Ruckdaschel. / S.M. in Engineering and Management / S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program

Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, May, 2020 / Cataloged from the official version of thesis. / Includes bibliographical references (pages 110-114). / This thesis examines rider multihoming in the US ridesharing market. Ridesharing services experience substantial multihoming on both sides of the platform, and appear to suffer from a combination of a lack of differentiation as well as low multihoming costs. Through an informational interview, a qualitative survey, and a conjoint survey and analysis, rider preferences were able to be categorized and quantified. An adapted conjoint survey and analysis allowed for a simulation of rider decisions to accept a ride or multihome along price, time, and company attributes. With baseline thresholds, examining the prevalence of multihoming with use of several multihoming reduction strategies, have shown that network bridging strategies may have an impact in reducing the prevalence of multihoming among riders. In-App Promotions and Incentive-based strategies, meanwhile, have shown to have the opposite results, showing an increased tendency to multihome in riders that utilize them. / by Daniel X. Valderrama. / S.M. in Engineering and Management / S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program

Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, September, 2020 / Cataloged from the official version of thesis. / Includes bibliographical references (pages 134-142). / Plant EPC projects, typically for LNG production plants, are the most expensive types of facilities in the world. While many of them have been built in the last several decades, the EPC cost did not decrease, and rather a significant cost increase in the last decade was observed. The most significant reasons are that the requirements became more complex, associated structure and piping facilities became more complex and heavier, more design change occurred during the EPC, supply-chains became more dominant and higher priced, workforce inflation occurred. Cost overrun and schedule delay of plant EPC business is quite common; however, it causes heavy pain for many associated enterprises. While many lessons have accumulated in organizations and many experienced brilliant engineers and project managers are doing their best to eliminate cost overruns and schedule delays, not many projects can successfully manage their completion within budget on schedule. This makes the LNG price higher. On the other hand, societal pressure has become high to decrease LNG price. While the world's LNG demand is expected to increase, many of the off-takers cannot make economic sense above the LNG price of $6/mmBtu because high pressure to reduce carbon emission renders their infrastructures more complex and expensive. LNG is a prospective energy source that can reduce world carbon emission substituting for coal and oil that emit twice as much greenhouse gas as LNG does per unit energy. To reduce global warming, EPC contractors of LNG plants could play a significant role. This thesis explores the current problems faced by their EPC business, and seeks to make EPC more valuable and lower cost by transforming the enterprise architecture of EPC contractors. / by Takeshi Fukatsu. / S.M. in Engineering and Management / S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program

Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, May, 2020 / Cataloged from the official version of thesis. / Includes bibliographical references (pages 44-46). / This is a last-mile mobility business model for developing countries. It analyzes current innovation and trends in rideshare and last-mile transportation. It states the challenges of transportation systems in our urban ecosystems, as well as the intimate relationship between transportation and energy demand, energy sources, and environmental impact. This thesis mimics a pilot case study in Bogota, Colombia, a city with tremendous mobility challenges, high unemployment, and robust bicycle infrastructure; characteristics that multiple cities in Latin America have in common. Finally, it proposes a last-mile transportation system that is sustainable, efficient, and inclusive with a concept vehicle and an innovation strategy. / by Jairo Ernesto Rodriguez Tovar. / S.M. in Engineering and Management / S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program

Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, September, 2020 / Cataloged from the official version of thesis. / Includes bibliographical references (pages 69-75). / The feasibility of utilizing the offshore environment and its resources to address the energy challenges identified by the Japanese Government is presented in this thesis. The thesis will be framed by the key energy challenges which include: (1) energy security, (2) environmental impact, (3) economy efficiency and (4) safety. The unique energy situation that Japan is in due to its geography, historic energy policies and energy economy will be considered as well. Subsequently, possible offshore energies to address the challenges Japan faces such as its lack of land space, societal acceptance of nuclear energy, lack of energy resources and its high frequencies of seismic activities will be examined. Finally, using system dynamics modelling, an abstracted model of Japan's energy industry will be used to study the feasibilities and the potential impacts of the proposed offshore solutions. Specifically, the model examines the impacts on Japan's energy self-sufficiency, electricity pricing and CO₂ emissions. The model will show that based on Japan's Business As Usual (BAU) approach, it would likely not meet its intended energy security, economic and, environmental targets. Two key conclusions are drawn from the study on Japan's energy policy and modelling results. First, Japan's decision to meet the diverse range of demands on their energy solution leads them to set inconsistent energy goals. This in turn overly restricts their energy solutioning. Second, that greater energy diversity through offshore energies will improve the prospects of helping Japan reduce projected electricity prices, enhance Japan's energy security through greater self-sufficiency and help reduce CO₂ emissions significantly. / by Caine Liew Xia Ri. / S.M. in Engineering and Management / S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program

Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, May, 2020 / Cataloged from the official version of thesis. / Includes bibliographical references (pages 86-88). / Most of Japan's railway infrastructure is decades old and requires efficient maintenance. However, pursuing efficiency is not easy because of strict safety requirements and many stakeholders that need to be considered. This study uses the ARIES framework to discuss the strategies that Japanese railway companies should take to achieve sustainable growth by maintaining safety and improving efficiency at the same time from the perspective of organizational design. The study uses the Central Japan Railway Company (CJR) as a representative of the industry. Firstly, the external environment of the organization is analyzed using seven important ecosystem factors, and stakeholder analysis identifies the key stakeholders and their values. In addition, the internal situation of the organization is investigated through eight view elements. The results of these analyses show that while CJR has strengths in infrastructure, a safety-oriented organizational culture, and specialized processes for railway operations, it has weaknesses in monitoring information and flexibility of decision-making, which may make it difficult to respond to changes in the external environment, such as population decline and the impact of COVID-19. These findings are incorporated into SWOT analysis and X-matrix analysis, and the possible strategies for CJR are discussed. As a result, six concepts and three alternative architectures based on these concepts are generated. Each alternative architecture is evaluated based on eight criteria, including safety, efficiency, and flexibility. The evaluation finds that aiming for a technology and data-oriented organization may be the most reasonable option for CJR. The study also suggests that a small, cross-functional team should lead the transformation and confirms the robustness of the selected architecture in three possible scenarios. Lastly, a feasible implementation plan with detailed architecture and alignment of internal metrics and processes is proposed. / by Yuki Soeda. / S.M. in Engineering and Management / S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program

Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, May, 2020 / Cataloged from the official version of thesis. / Includes bibliographical references (pages 71-76). / Falls and fall related injuries in the elderly (aged 65 and older) are a major health challenge - both to the affected individual and to the public health system. Approximately 28-35% of the elderly fall each year and falls lead to 20-30% of mild to severe injuries, and are underlying cause of 10-15% of all emergency room (ER) visits. Falls cause 90% of the hip fractures in the elderly and also result in medical complications and high morbidity if the person does not receive prompt medical attention. A fall mitigation system (FMS) is either a wearable or ambient system that detects falls, reduces fall related injuries and issues emergency alerts to prevent the long-lie. Current FMS have poor user adoption and are not as effective in preventing the long-lie. This thesis uses a systems approach to analyze architectures for a fall mitigation system architecture that can detect falls, reduce injury and issue emergency alerts to reliably prevent the long-lie in independent elders. A National Health Interview Survey data was analyzed to understand the causes for falls, types of fall related injuries and common fall locations for community dwelling elders. A concept of operations was defined based on these findings and a user survey was conducted to understand the needs of community dwelling elders and the results were analyzed to prioritize system requirements for a fall mitigation system (FMS). An FMS was decomposed into six level 2 functions and the various form choices for each of these functions were analyzed and rated for performance, power consumption and cost. Five different fall mitigation system architectures were analyzed and the Distributed-Hybrid architecture had the highest performance while the Integrated-Wearable architecture had the lowest power consumption. Future technology trends in robotics, AI, neuromorphic computing and energy harvesting were studied to create a long-term strategic roadmap for fall mitigation systems. Neuromorphic architectures for computing and sensing offer the biggest performance per unit power unlock for fall mitigation systems. / by Vikas Reddy Enti Ranga Reddy. / S.M. in Engineering and Management / S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program

Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, May, 2020 / Cataloged from the official version of thesis. Page 68 blank. / Includes bibliographical references (pages 65-67). / Middle ear infections or otitis media that cause inflammation of tympanic membrane and fluid buildup in the middle ear cavity accounts for 2-3 million hospital visits every year [34]. As per an epidemiological study conducted from 2006 - 2016 on 685 children, between the ages of 1-3 years, roughly 60% had at least one hospital visit due to ear infections [3]. Despite the high incidence, the diagnosis of otitis media is only 50% accurate (a coin toss) due to the subjective nature of diagnosis as the physicians look at the ear drum and detect the fluid behind the ear drum. To detect the fluid with high sensitivity and accurately diagnose middle ear infection, we propose a multispectral visible - nIR otoscope that operates in the range of 600 nm - 1050 nm. We have performed experiments to demonstrate the proof of concept of our device on phantoms that includes, 3D printed middle ear structure, tympanic membrane made of silicone, and orange juice as ear fluid all of which mimics the properties of human ear. The multispectral otoscope showed highest contrast between ossicles and fluid at 1000 nm which shows low attenuation of fluid and tympanic membrane at NIR wavelengths. The system is calibrated against a diffuse reflection surface to account for variations in source and detector. Our experiments showed that empty phantoms yielded almost equal contrast across the entire visible- NIR wavelength. Once the fluid is filled, the contrast increased by 30 ± 10 % in the visible wavelength (600 nm - 750 nm) and 120 ± 20 % in nIR wavelength (900 nm - 1000 nm). This 80% - 100% difference in contrast between visible and NIR wavelength is used to detect and highlight the areas of the middle ear filled with fluid. / by Gokul Prasath Rajamanickam. / S.M. in Engineering and Management / S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program

Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, September, 2020 / Cataloged from the official version of thesis. "September 2020." / Includes bibliographical references (pages 115-118). / This thesis describes a stacked ensemble, supervised machine learning problem for well rate estimations utilizing well test features that are far from independent and identically distributed (IID), and exhibit missing data with a not missing at random (MNAR) classification from three different oil fields. This research introduces a novel integrated imputation procedure that combines the imputation model selection with the cross-validation procedure for downstream model tuning without data "leakage"--the primary objective shifts from minimizing the imputation data error to minimizing the downstream hold-out error. A stratified time-slicing rolling forecast cross-validation procedure is implemented to minimize over-fitting from the plethora of statistical assumptions that are violated. This thesis seeks to test a framework that will enable well rate estimations for fields available well test data to improve well surveillance capabilities in order to maximize production metrics and minimize adverse health and environmental impacts. / by Oliver John Wilson. / S.M. in Engineering and Management / S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program

Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, System Design and Management Program, February, 2021 / Cataloged from the official version of thesis. "February 2021." / Includes bibliographical references (pages 76-79). / Geospatial-temporal data for different e-scooter firms was collected and investigated for differences in e-scooter usage patterns among customers of the firms. Computational analysis using predictive algorithms and correlation analysis was done to find co-relationally important features for predicting the dependent variable. Data-preprocessing included computing trips from geospatial data and dividing the city into smaller clusters for analysis using geohashes. Hourly weather data was added to the geospatial temporal data to account for weather impact on the number of trips. The Spatio-temporal analysis shows a correlation between the percentage of scooters parked at a location and the success rate of the firm with the highest scooters getting the highest number of trips. / by Gulsagar Singh Jassar. / S.M. in Engineering and Management / S.M.inEngineeringandManagement Massachusetts Institute of Technology, System Design and Management Program