The purpose of this study was to ascertain the most economically feasible method for high volume machining of a discharge hole in a power metal compressor cylinder.

Thesis: M.S., Massachusetts Institute of Technology, Department of Civil Engineering, 1975 / Bibliography: leaf 95. / M.S. / M.S. Massachusetts Institute of Technology, Department of Civil Engineering

A model for optimizing the assignment of maintenance actions for a piece of equipment is developed in the thesis. The model considers the detectability and the criticality of component failure in order to assign a maintenance instruction. The thesis also develops the framework for an integrated maintenance management system. The system consists of three modules. The first module is work control. It is used to prepare, schedule, and insure the execution of maintenance instructions. The second module is the equipment condition control module which monitors maintenance effectiveness and accordingly updates the maintenance instructions. The third module is cost control. This is the tool used to monitor the economical performance of the maintenance function. An equipment information system is also presented, and two futuristic maintenance proposals are introduced. The model and the integrated maintenance management system, constitute a strong tool, that equipment managers can use to optimize the maintenance function, and improve the mechanical, operational, and economical performance of equipment. / Master of Science

The initial forecasting of logistical support for new types of military aircraft is a perplexing problem. The objective of this research was to investigate the feasibility of using data generated by the accelerated flight tests as a basis for forecasting the logistical field requirements. The data used in the study were obtained from the U.S. Army Aviation Board, Fort Rucker, Alabama, where performance tests are conducted on all new aircraft to determine their suitability for Army use. It was statistically shown that the use of these data could provide more realistic logistical forecasts earlier in the introductory phase of the aircraft. This concept would increase the operational availability of the aircraft and reduce the cost of maintaining the aircraft during its introductory phase.

published_or_final_version / Civil Engineering / Master / Master of Philosophy

M.Comm. / Operational management is to plan and control the transformation process that converts the requirements of customers into a product or a service. The non programmed refurbishing of railway wagons at Transwerk (Germiston) is a very difficult task for the operational manager. The number of wagons and what to repair on each wagon, only become known when the wagon arrives at Transwerk. The planning and scheduling of resources like labour, material, facilities, equipment and cash flow are therefor not so easy. To overcome the difficulties of the planning and scheduling of resources, and to refurbish the wagons according to the customer's requirements and satisfaction, it is necessary to have an operational management model or system. This system comprises of functions like aggregate planning, production scheduling, planning for fixed and variable capacities, inventory planning, design of the operational process itself as well as the control of the whole system. All of this must be set in a framework of the company's overall strategy as well as the financial and operational strategies. The first part of this study deals with the heories of operational management. It is important that the operational manager is familiar with the types of decisions to be made and what concepts are available to optimise his decisions. He also needs to know which product positioning strategy and which process positioning strategy to take. In the case of Transwerk a make-to-order product positioning strategy will be used to refurbish the wagons, and a make-to-stock strategy to manufacture the components that are needed to repair the wagons. A job-shop process positioning strategy will be used, because no fixed process flow can be followed to repair the different wagons. In the second part of this study an empirical research was done. The frequency and number of the different types of wagons that were sent to Transwerk, as well as the occurrence of the repair types on the wagons, were researched. Four years (1992 to 1995 book year) of information were used. The number of wagons and when the wagons might come in for repairs in 1996, as well as what types of repairs to do, are forecasted by using quantitative techniques as time series decomposition and weighted moving averages. The forecast or aggregate plan is the starting point of any operational model. Finally the operational model is designed. The model starts with the business- and operational strategies followed by the production plan. The production plan, derived from the forecast, shows the wagons that are expected to be built for the next five years. Transwerk should check the major available resources to assure that the production can be met. After the production plan is authorised by the executive manager the operational manager can do the master schedule. This schedule shows by model level which wagon types are expected to be repaired per day per month. This information also comes from the forecast that was done. Out of the master schedule, the material- and capacity plans can be drawn up. Production can start once the operational manager finds the planning to be correct. It is important that every step in the model is controlled and that the plans are changed if necessary. A well defined operational management model will help Transwerk on the way to be a world class company.

李嘉寶. / "2007年8月". / 論文(哲學碩士)--香港中文大學, 2007. / 參考文獻(leaves 121-129). / "2007 nian 8 yue". / Abstract also in English. / Li Jiabao. / Lun wen (zhe xue shuo shi)--Xianggang Zhong wen da xue, 2007. / Can kao wen xian (leaves 121-129). / 緒論 / Chapter 1. --- 前言 --- p.1 / Chapter 2. --- 硏究回顧 --- p.3 / Chapter 3. --- 論文寫作框架 --- p.13 / Chapter 第一章 --- 修橋補路一一明清時期的慈善、國家與社會 / Chapter 1. --- 前言 --- p.15 / Chapter 2. --- 蘇松地區的修橋統計 --- p.18 / Chapter 3. --- 矛盾的修橋者一一有責無錢的官員 --- p.22 / Chapter 4. --- 慈善的修橋者一一行善積德的士紳 --- p.33 / Chapter 5. --- 修橋補路的中介者一一善堂的興起 --- p.42 / Chapter 6. --- 小結一一從修橋補路看國家與社會關係 --- p.45 / Chapter 第二章 --- 上海地方自治與路政發展 / Chapter 1. --- 前言 --- p.47 / Chapter 2. --- 兩種制度的相遇一一南市路政的起步 --- p.49 / Chapter 3. --- 自治十年的路政發展 --- p.58 / Chapter 4. --- 路政的經濟基礎 --- p.70 / Chapter 5. --- 小結 --- p.75 / Chapter 第三章 --- 自治與社會 / Chapter 1. --- 前言 --- p.76 / Chapter 2. --- 從慈善到路政之過渡 --- p.77 / Chapter 3. --- 自治組織的權威危機與加強 --- p.85 / Chapter 4. --- 小結 --- p.95 / Chapter 第四章 --- 自治與國家 / Chapter 1. --- 前言 --- p.96 / Chapter 2. --- 城濠公地案中自治組織與地方政府的關係 --- p.97 / Chapter 3. --- 拆城築路案中自治組織與地方政府的關係 --- p.101 / Chapter 4. --- 兩案之結局 --- p.109 / Chapter 5. --- 小結 --- p.115 / 結論 --- p.117 / 參考書目 --- p.121

Thesis. 1977. M.Arch.--Massachusetts Institute of Technology. Dept. of Architecture. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH. / Bibliography : leaf 58. / by Marcia K. Hnatowich. / M.Arch.

This dissertation focuses on the development of data analytics approaches to two distinct important condition monitoring applications in civil infrastructure: structural health monitoring and road surface monitoring. In the first part, measured vibration responses of a major long-span bridge are used to identify its modal properties. Variations in natural frequencies over a daily cycle have been observed with measured data, which are probably due to environmental effects such as temperature and traffic. With a focus on understanding the relationships between natural frequencies and temperatures, a controlled simulation-based study is conducted with the use of a full-scale finite element (FE) model and four regression models. In addition to the temperature effect study, the identified modal properties and the FE model are used to explore both deterministic and probabilistic model updating approaches. In the deterministic approach (sensitivity-based model updating), the regularization technique is applied to deal with a trade-off between natural frequency and mode shape agreements. Specific nonlinear constraints on mode shape agreements are suggested here. Their capabilities to adjust mode shape agreements are validated with the FE model. To the best of the author's knowledge, the sensitivity-based clustering technique, which enables one to determine efficient updating parameters based on a sensitivity analysis, has not previously been applied to any civil structure. Therefore, this technique is adapted and applied to a full-scale bridge model for the first time to highlight its capability and robustness to select physically meaningful updating parameters based on the sensitivity of natural frequencies with respect to both mass and stiffness-related physical parameters. Efficient and physically meaningful updating parameters are determined by the sensitivity-based clustering technique, resulting in an updated model that has a better agreement with measured data sets. When it comes to the probabilistic approach, the application of Bayesian model updating to large-scale civil structures based on real data is very rare and challenging due to the high level of uncertainties associated with the complexity of a large-scale model and variations in natural frequencies and mode shapes identified from real measured data. In this dissertation, the full-scale FE model is updated via the Bayesian model updating framework in an effort to explore the applicability of Bayesian model updating to a more complex and realistic problem. Uncertainties of updating parameters, uncertainty reductions due to information provided by data sets, and uncertainty propagations to modal properties of the FE model are estimated based on generated posterior samples. In the second part of this dissertation, a new innovative framework is developed to collect pavement distress data via multiple vehicles. Vehicle vibration responses are used to detect isolated pavement distress and rough road surfaces. GPS positioning data are used to localize identified road conditions. A real-time local data logging algorithm is developed to increase the efficiency of data logging in each vehicle client. Supervised machine learning algorithms are implemented to classify measured dynamic responses into three categories. Since data are collected from multiple vehicles, the trajectory clustering algorithm is introduced to integrate various trajectories to provide a compact format of information about road surface conditions. The suggested framework is tested and evaluated in real road networks.

The objective of this project was to evaluate methods to remediate a wood I-joist with a single, circular hole in the web while leaving utilities in place. The methods were experimentally evaluated with a full-scale bending test using four equally spaced point loads. There were three depths of joists with varying flange widths and two span lengths (4.88 m & 2.44 m). Failure modes for the long span joists without holes were in the flanges in either tension, compression or lateral buckling; but once a hole was introduced the majority were classified as shear failures. Effectiveness of the remediation was evaluated based on three criteria: strength, stiffness, and ease of installation/cost. The OSB collar patch was effective for 8 out of the 12 series tested. A maximum reduction of load from a joist with no hole to one with a hole was 49% for the long span and 58% for the short span. The OSB collar was not as effective in returning stiffness to the joists, but was easier to install and less expensive than the LSL patch. / Graduation date: 2013