Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1996. / Includes bibliographical references (p. 135-136). / by Hoang Huu Tran. / M.S.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2005. / Includes bibliographical references (p. 148-150). / This thesis presents a new approach for a Navy unmanned undersea vehicle (UUV) to search for and detect an evading contact. This approach uses a contact position distribution from a generic particle filter to estimate the state of a single moving contact and to plan the path that minimizes the uncertainty in the location of the contact. The search algorithms introduced in this thesis will implement a motion planner that searches for a contact with the following information available to the decision system: (1) null measurement (i.e., contact not detected at current time), (2) timedated measurement (i.e., clue found at current time that indicates contact was at this location in the past), and (3) bearings measurement (i.e., angular measurement towards contact position detected at current time). The results of this thesis will be arrived at by evaluating the best methods to utilize the three types of information. The underlying distribution of the contact state space will be modeled using a generic particle filter, due to the highly non-Gaussian distributions that result from the conditions mentioned above. Using the particle filter distribution and the measurements acquired from the three conditions, this thesis will work towards implementing a path planning algorithm that creates dynamic action spaces that evaluate the uncertainty of position distribution. Ultimately, the path planner will choose the path that contains the position distribution and leads to sustained searches. / by Caleb A. Earnest. / S.M.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2009. / Includes bibliographical references (p. 49). / Over the past century, there have existed two major types of structural engineers. Some, like Robert Maillart, contributed greatly to the advancement of new forms. Others, such as Peter Rice, produced their most innovative work in collaboration with architects. The present study analyzes the work and methodology of both groups of engineers, with the purpose of defining the common ground between them. Finally, there is a detailed discussion of the 'form-makers' and 'collaborators' in the context of the present day, in an effort to describe the basis for quality in structural engineering. / by Alice Tao. / M.Eng.

Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2000. / Includes bibliographical references (leaves 52-54). / by Panagiota E. Paraoulaki. / M.Eng.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2003. / Includes bibliographical references (leaves 76-78). / by Naz E. Majidi. / S.M.

Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2001. / Includes bibliographical references (p. 80). / Data modeling is one of the critical steps in the software development process. The use of data becomes a profitable business today and the data itself is a valuable asset of the company. In this thesis, the process of developing a data model will be introduced in the first part. The second part will be a case study. The case study is about the development of the data model of a pavement management system. This is an actual project implemented for the Public Works Department of Arlington, MA. / by Wai-Kei Yim. / M.Eng.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2007. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Includes bibliographical references (leaves 106-111). / The recent rises in resident and tourist populations on St. John in the U.S. Virgin Islands have spurred the construction of new roads and housing developments throughout much of the island. As a result, a number of pollutants, including sediment and nitrogen, are being delivered to the coastal waters around the island at increasing rates and are believed to be having adverse impacts on the health of coral reef ecosystems. Understanding the impacts of increased sediment and nitrogen loads on coral reefs is critical for the protection of these valuable natural resources. In the present study, two mass balance models for sediment and nitrogen were developed to evaluate the impact of watershed development on the water quality of coastal embayments. The sediment model considered inputs by watershed loading and losses by gravitational settling and tidal flushing. The degree of sediment stress inflicted upon each bay was evaluated using three stress metrics. The results of the sediment model agreed with historical turbidity measurements collected by the National Park Service in terms of the relative degree of sediment stress observed in each bay. / (cont.) A mass balance model for nitrogen was also developed accounting for input fluxes by groundwater discharge, atmospheric deposition, and nitrogen fixation and output fluxes by tidal flushing and denitrification. The biological fluxes of nitrogen were orders of magnitude greater than the physical fluxes suggesting that nitrogen availability in these ecosystems may be controlled mainly by microbial processes and not by external inputs. Accounting only for the physical fluxes, steady-state inorganic nitrogen concentrations agreed with historical measurements of inorganic nitrogen collected by the National Park Service. The model results indicated elevated levels of sediment and nitrogen in bays with watersheds that are more developed and have larger areas. Overall, this study provides strong evidence that both watershed development and watershed size are closely related to deteriorating water quality in coastal bays around St. John, and further studies of nitrogen and sediment pollution are warranted. / by Jeffrey D. Walker. / M.Eng.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1996. / Includes bibliographical references (leaves 82-85). / by Suzanne W. Wetzel. / M.S.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1991. / Includes bibliographical references (leaves 65-67). / by Anne Marie Slinn. / M.S.

Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2000. / "June 2000." / Includes bibliographical references (leaves 86-88). / by Marnie A. Bell and Beth A. Manoogian. / M.Eng.