Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2003. / Paged continuously. Each page no. is preceded by a chapter no. / Includes bibliographical references (leaves 88-89). / In today's supermarket world, consumers apart from demanding 'higher and higher quality at lower and lower prices', want more and more product choices. This has put tremendous pressure on supermarkets and their infrastructure. With better information technology, forecasting techniques, planning tools, demand fulfillment and supplier relationships supermarkets can meet the rising demand much better than ever before. But inorder to meet this demand at the lowest price they need to rethink their inbound logistics and re-optimize their warehouses. This has spurred a growth in warehousing outsourcing. The study is concerned with evaluating the cost benefit between the internal and the external warehousing for the food retail industry, while addressing the following issues: 1. Advantages and disadvantages of an internal and external warehouse. 2. Importance of alignment of logistics strategy and corporate strategy. 3. Vendor items which should be outsourced or insourced The study was conducted by evaluating the economic value for fifteen different vendors of a regional supermarket chain with the objective to help the supermarket chain reassess its warehousing strategy. / by Vikas Mehrotra. / M.Eng.in Logistics

Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2009. / Includes bibliographical references (leaves 105-106). / Prediction Markets hold the promise of improving the forecasting process. Research has shown that Prediction Markets can develop more accurate forecasts than polls or experts. Our research concentrated on analyzing Prediction Markets for business decision-making. We configured a Prediction Market to gather primary data, sent out surveys to gauge participant views and conducted in-depth interviews to explain trader behavior. Our research was conducted with 169 employees from General Mills who participated in Prediction Markets that lasted from two to ten weeks. Our research indicates that short term forecasting Prediction Markets are no more accurate than conventional forecasting methods. It also presents and addresses three interesting contradictions. First, the Sales Organization won the majority of the Prediction Markets, yet the overall performance of Sales as a group was worse than that of other groups. Second, Prediction Markets were able to gain access to more information than General Mills' current process, yet the impact on forecast accuracy was not significant. Third, with a MAPE of 11% for promotional Prediction Markets, it would seem that promotional demand was well understood up-front, yet when we dissected the promotional forecasts we discovered that participants changed their minds over time degrading overall forecast accuracy. We believe that we have extended the current body of work on Prediction Markets in ways that will increase the utilization in business environments. / by Kai Trepte and Rajaram Narayanaswamy. / M.Eng.in Logistics

Thesis (Ph. D.)--Massachusetts Institute of Technology, Division of Bioengineering and Environmental Health, 1999. / Includes bibliographical references (leaves 186-205). / by Xiaocheng Li-Suckoleiki. / Ph.D.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Biological Engineering Division, 2004. / Includes bibliographical references (leaves 84-93). / Non-parenchymal cells (NPC's) are integral to recreate the native hepatic microenvironment and necessary to maintain in vivo liver function. A variety of in vitro culture systems have been developed to address different aspects of liver physiology and architecture in order to recreate the microenvironment. These in vitro co-culture strategies have been limited by their inability to systematically characterize the addition of non-parenchymal cells. In this dissertation, I use gene expression levels quantified by real-time RT-PCR to determine tissue composition. The identified genes demonstrate significant cell-type specificity, magnitude, and stability of expression in vivo and throughout each step of cell isolation process. In the course of this development, we establish protocols to accurately isolate and count an enriched fraction of primary NPC's. Experiments on the perfusion and isolation process prove that there exists an inverse correlation between perfusion flow rate and NPC yield and viability. Further, we have characterized the tissue composition of each step in the cell isolation process and the resulting NPC population to confirm that a significant number of each NPC type is delivered to in vitro co-culture. System output analysis of spheroids co-cultured at physiological ratios and seeded into the milliF bioreactor shows the presence of stellate cells, but the absence of endothelial (EC) and kupffer cells (KC). The same analysis of 2D collagen gel sandwiches shows the presence of all NPC cell types. This indicates that our process is currently limited by the ability of EC's and KC's to incorporate into spheroid aggregates. Future work that validates the temporal expression stability of the identified genes in different in vitro culture systems / (cont.) and environments will enable determination of relative levels of NPC incorporation and will allow correlations to be made between operational features of in vitro systems, the resulting culture microenvironment, and observed tissue function. / by Brent M. Schreiber. / M.Eng.

Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2004. / "June 2004." / Includes bibliographical references (leaves 48-51). / One of the entry points of radio frequency identification technology in supply chain applications is at the manufacturing line, after production, as packaged goods leave for the next link of the network of suppliers, carriers, distributors and retailers. To RFID-enable packaged products, an RFID device needs to be attached to the packaging and an identification number needs to be generated and stored accordingly. Today, a few early adopters of the technology already started to apply RFID tags to some of their cases and pallets and to collect and store the information. These processes however, are still to a large extent done at a slow pace, manually or in an experimental mode, and that may not be suited for large scale applications. To address this issue, this research document focuses on the implementation of an RFID enabled process under strict time and performance constraints, for case packaged goods and pallets. This document reviews the currently published information on the topic and the Auto-ID technology standards. It analyses system integration challenges, proposes a process for case and pallet level encoding, application and association and discusses some of information systems requirements for the implementation. It proposes a framework of options with the requirements and considerations the author believes to be most relevant. / by Herbert Moreti Fonseca. / M.Eng.in Logistics

Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2013. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Cataloged from student-submitted PDF version of thesis. / Includes bibliographical references. / Traditional methods to identify and document hazards, and the corresponding safety constraints, are lacking in their ability to account for human, software and sub-system interactions in highly technical systems. STAMP, a systems-theoretic accident causality model, was created to overcome these limitations. The application of STAMP hazard analysis method STPA to five sub-systems of the Paul Scherrer Institute's experimental PROSCAN proton therapy system demonstrated how STPA can augment design and risk review of existing complex systems. Two of the five human controllers active in treatment delivery, two of the four process attributes controlled by the PROSCAN facility, and one of the four control loops that control the beam to target alignment attribute were analyzed. In doing so, the following contributions were made: - Analyzed the regulations currently in place in the US and Europe for the marketing of external beam radiotherapy devices and, more generally, medical devices that do not contain radioactive materials, concluding that STPA would be acceptable in both regulatory systems; - Provided experience in applying STPA to a complex device. Information on efficacy was derived by comparing STPA results with an existing safety assessment but a more formal counterpart is needed for stronger evidence. Information on learnability and usability was obtained when an informal workshop showed that system designers, in the course of one day, could be taught to use STPA to push their thinking about yet to be designed system elements; - Demonstrated the applicability of STPA to an experimental radiotherapy facility and, through this feasibility check, potentially influenced the state of the art in hazard analysis of medical devices and health care delivery; - Advanced the STPA methodology by creating notations and a process to document, query and visualize the possibly large number of hazardous scenarios identified by STPA analyses, with the goal of facilitating their review and use by their intended audience; Showed how STPA is complementary to more traditional hazard analysis techniques such as fault and event trees. Their respective strengths can be summoned when STPA is used to identify areas on which to focus the investigation lens of traditional hazard analysis techniques. Keywords: STAMP, STPA, hazard analysis, risk analysis, risk management, proton therapy, medical devices, safety, certification / by Blandine Antoine. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Biological Engineering Division, 2008. / Includes bibliographical references (p. 157-169). / Cells use a complex web of protein signaling pathways to interpret extracellular cues and decide and execute cell fates such as survival, apoptosis, differentiation, and proliferation. Cell decisions can be triggered by subtle, transient signals that are context specific, making them hard to study by conventional experimental methods. In this thesis, we use a systems approach combining quantitative experiments with computational modeling and analysis to understand the regulation of the survival-vs-death decision. A second goal of this thesis was to develop modeling and analysis methods that enable study of signals that are transient or at intermediate activation levels. We addressed the challenge of balancing mechanistic detail and ease of interpretation in modeling by adapting fuzzy logic to analyze a previously published experimental dataset characterizing the dynamic behavior of kinase pathways governing apoptosis in human colon carcinoma cells. Simulations of our fuzzy logic model recapitulated most features of the data and generated several predictions involving pathway crosstalk and regulation. Fuzzy logic models are flexible, able to incorporate qualitative and noisy data, and powerful enough to generate not only quantitative predictions but also biological insights concerning operation of signaling networks. To study transient signals in differential-equation based models, we employed direct Lyapunov exponents (DLEs) to identify phase-space domains of high sensitivity to initial conditions. These domains delineate regions exhibiting qualitatively different transient activities that would be indistinguishable using steady-state analysis but which correspond to different outcomes. / (cont.) We combine DLE analysis of a physicochemical model of receptor-mediated apoptosis with single cell data obtained by flow cytometry and FRET-based reporters in live-cell microscopy to classify conditions that alter the usage of two apoptosis pathways (Type I/II apoptosis). While it is generally thought that the control point for Type I/II occurs at the level of initiator caspase activation, we find that Type II cells can be converted to Type I by removal of XIAP, a regulator of effector caspases. Our study suggests that the classification of cells as Type I or II obscures a third variable category of cells that are highly sensitive to changes in the concentrations of key apoptotic network proteins. / by Bree Beardsley Aldridge. / Ph.D.

Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2004. / Includes bibliographical references (leaves 66-67). / (cont.) boundary and leave more demand uncertainty to the pull part of the system. / Based on a particular case study, this paper presents two approaches to buffer management under demand uncertainty, which is characterized by high lumpiness, dispersion and volatility. The common theme of both of the two approaches is not to find an advanced statistical method to improve demand forecast on the basis of historical data. Rather, these approaches provide new business paradigms to deal with demand uncertainty. The first approach, make-to-anticipated-order (MTAO), takes advantage of the mechanism of make-to-order (MTO) and develops a process that the production is pulled by anticipated orders instead of being pushed by the forecast of unpredictable future demand. The implementation of this method, on one hand, breaks through the precondition of MTO that the total production cycle time should be less than customers' desired lead-time. On the other hand, MTAO enjoys the advantage of arranging production by responding to customer demand to reduce inventory costs and obsolescence risks of MPS level items. The second approach makes use of postponement and commonality strategy to lower demand uncertainty. The basic principle is that aggregate demand is more stable than disaggregate demand. Thus, if a common module instead of various individual modules in a module family acts as a MPS item, the demand of the common module will represent the aggregate demand of all individual modules in the module family and more accurate forecast can be made. Then by using the forecasted demand distribution of the common module, we can figure out optimized multistage inventory placement to buffer demand uncertainty with the minimum holding cost of total safety stock. In effect, by implementing postponement and commonality strategy, we change the push-pull / by Zhiyu Xu. / M.Eng.in Logistics

Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2005. / Includes bibliographical references (v. 2, p. 311-316). / The electric power system in the US developed with the assumption of exogenous, inelastic demand. The resulting evolution of the power system reinforced this assumption as nearly all controls, monitors, and feedbacks were implemented on the supply side. Time invariant, averaged retail pricing was a natural extension of the assumption of exogenous demand and also reinforced this condition. As a result, the market designs and physical control of the system exclude active participation by consumers. Advances in information and communications technologies enable cost effective integration of demand response. Integrating demand into the US electricity system will allow the development of a more complete market and has the potential for large efficiency gains. Without feedbacks between supply and demand, attempts to develop competitive markets for electricity will suffer from a greater potential for market power and system failure. This thesis provides an analysis of the technical, regulatory, and market issues to determine a system structure that provides incentives for demand response. An integrated, dynamic simulation model is utilized to demonstrate the effects of large scale adoption of demand response technologies. The model includes distributed decision making by both consumers and investors in generation capacity, the effects of their decisions on market prices, and the feedbacks between them. Large scale adoption of demand response technology is simulated to quantify the potential benefits of responsive demand. The effects of technology improvement via learning, long term demand elasticity, and policies to promote adoption are considered. / (cont.) The simulations show that diminishing returns for adopters and free rider effects limit the attractiveness of individual adoption. A subsidy to alleviate the costs to adopters can be justified by the significant system level savings from widespread participation. Several pernicious effects can emerge from large scale demand response, however, including increased price volatility due to reductions in generation capacity reserve margin, increases in long term demand, and increased emissions from the substitution of peak generation capacity, such as natural gas and renewables by intermediate capacity. Significant rent transfers will also occur, and stakeholder analysis is conducted to determine interests and distributional effects of large scale demand response. / by Jason W. Black. / Ph.D.

Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2011. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 73). / A large U.S. based retailer underwent a large, complex multi-year supply chain network transformation. This transformation resulted in significant savings in logistics costs. Additionally, the regional distribution center that was introduced as part of this transformation as a new node between the supplier and the store became the decision making center for placing purchase orders with suppliers and for receiving and shipping the purchase order to individual stores. This resulted in longer lead times causing a change in the in-store units held and therefore, directly impacting the net sales. This thesis focuses on establishing the relationship between the stores performance and lead-time, review-time combinations in both supply chain networks, the original direct to store and the new regional distribution based networks. / by Sunil Anand and Xiaobei Song. / M.Eng.in Logistics