• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 127894
  • 18477
  • 11185
  • 8080
  • 6926
  • 6926
  • 6926
  • 6926
  • 6926
  • 6900
  • 5590
  • 2328
  • 1457
  • 1297
  • 527
  • Tagged with
  • 215496
  • 40010
  • 33247
  • 30008
  • 28090
  • 25647
  • 22156
  • 19085
  • 16610
  • 16094
  • 16055
  • 13227
  • 12869
  • 12842
  • 12744
  • 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.
201

Transactions of the International Engineering Congress, 1915 ...

January 1900 (has links)
(V. 1) The Panama canal. 2 v.--(v. 2) Waterways and irrigation.--(v. 3) Municipal engineering.--(v. 4) Railway engineering.--(v. 5) Materials of engineering construction.--(v. 6) Mechanical engineering.--(v. 7) Electrical engineering and hydroelectric power development.--(v. 8) Mining engineering.--(v. 9) Metallurgy.--(v. 10) Naval architecture and marine engineering.--(v. 11) Miscellany.--(v. 12) Index volume.
202

Engineering books available in America prior to 1830

Shaw, Ralph R. January 1933 (has links)
Thesis (M.S.)--Columbia University, 1931. / "Reprinted from the Bulletin of the New York Public Library of Jan.-April, June 1933."
203

A cost-effectiveness approach to analysis of the process of allocating scarce manpower resources to perform general systems engineering and technical direction /

O'Brien, William Richard, January 1971 (has links)
Thesis (Ph. D.)--Ohio State University, 1972. / Includes bibliographical references (leaves 229-232). Available online via OhioLINK's ETD Center.
204

A survey of national engineering education initiative leaders what knowledge do students and technology education teachers need to be successful in an engineering education curriculum? /

Martin, Larry. January 2005 (has links) (PDF)
Thesis, PlanB (M.S.)--University of Wisconsin--Stout, 2005. / Includes bibliographical references.
205

A three-dimensional crack tip element for energy release rate determination and delamination growth prediction

Yu, LiJie. January 2002 (has links)
Thesis (PH.D.) -- Syracuse University, 2002. / "Publication number AAT 3045799 "
206

Designing cooperative learning events, peer mentoring interactions, and mentoring roles for engineering education /

Zemke, Steven C. January 1900 (has links)
Thesis (Ph. D.)--University of Idaho, 2005. / Abstract. "May 2005." Includes bibliographical references. Also available online in PDF format.
207

Robust model-based fault estimation and fault-tolerant control : towards an integration

Lan, Jianglin January 2017 (has links)
To maintain robustly acceptable system performance, fault estimation (FE) is adopted to reconstruct fault signals and a fault-tolerant control (FTC) controller is employed to compensate for the fault effects. The inevitably existing system and estimation uncertainties result in the so-called bi-directional robustness interactions defined in this work between the FE and FTC functions, which gives rise to an important and challenging yet open integrated FE/FTC design problem concerned in this thesis. An example of fault-tolerant wind turbine pitch control is provided as a practical motivation for integrated FE/FTC design. To achieve the integrated FE/FTC design for linear systems, two strategies are proposed. A H∞ optimization based approach is first proposed for linear systems with differentiable matched faults, using augmented state unknown input observer FE and adaptive sliding mode FTC. The integrated design is converted into an observer-based robust control problem solved via a single-step linear matrix inequality formulation. With the purpose of an integrated design with more freedom and also applicable for a range of general fault scenarios, a decoupling approach is further proposed. This approach can estimate and compensate unmatched non-differentiable faults and perturbations by combined adaptive sliding mode augmented state unknown input observer and backstepping FTC controller. The observer structure renders a recovery of the Separation Principle and allows great freedom for the FE/FTC designs. Integrated FE/FTC design strategies are also developed for Takagi-Sugeno fuzzy modelling nonlinear systems, Lipschitz nonlinear systems, and large-scale interconnected systems, based on extensions of the H∞ optimization approach for linear systems. Tutorial examples are used to illustrate the design strategies for each approach. Physical systems, a 3-DOF (degree-of-freedom) helicopter and a 3-machine power system, are used to provide further evaluation of the proposed integrated FE/FTC strategies. Future research on this subject is also outlined.
208

Detection performance and mitigation techniques in CR networks

Ammar, Mahmod January 2017 (has links)
Pervasive wireless communications rely enormously on spectrum utilization; the increase in demand for new wireless services and their application has led to spectrum scarcity. Spectrum limitations can be resolved by cognitive radio (CR) which is a technology that allows secondary users (SUs) to use the spectrum when it is not occupied by primary users (PUs). In this thesis, the security issues that decrease CR performance are discussed; there are two major threats i.e. primary user emulation attack (PUEA) and spectrum sensing data falsification attack (SSDF). Firstly, the CR network (CRN) is simulated whereby PUs and SUs are presented in the system with the presence of multiple malicious users that are randomly located within a circle of radius (R). The simulation results, based on an analytical model, show that the false alarm probability is significantly affected by the network radius Rand malicious users' number, and it is proved that there is a range of R over which the PUEAs are most successful. Secondly, a transmitter verification scheme (direct scheme) and indirect trust scheme that considers the users' history are presented; the results proved that if the signal to noise ratio (SNR) is raised, correspondingly the t:rnstworthiness of the PU is considerably increased. Based on these two schemes, the trnstworthiness of the PU is much higher than that of the malicious user and because the indirect scheme considers the historical behaviour of the user, it improves the user's trustworthiness. Finally, cooperative spectrum sensing (CSS) approaches are proposed, namely, a trust based approach, a punishment based approach and a dedicated punishment based approach. It is proved that these proposed CSS approaches outperform the traditional majority scheme despite a high number of malicious users. In addition, the dedicated punishment approaches which punish only the malicious users outperform the other approaches.
209

Experimental Study of the Flow Field in a Model 1.5-Stage Gas Turbine Rotor-Stator Disk Cavity

January 2010 (has links)
abstract: A major concern in the operation of present-day gas turbine engines is the ingestion of hot mainstream gas into rotor-stator disk cavities of the high-pressure turbine stages. Although the engines require high gas temperature at turbine entry for good performance efficiency, the ingested gas shortens the lives of the cavity internals, particularly that of the rotor disks. Steps such as installing seals at the disk rims and injecting purge (secondary) air bled from the compressor discharge into the cavities are implemented to reduce the gas ingestion. Although there are advantages to the above-mentioned steps, the performance of a gas turbine engine is diminished by the purge air bleed-off. This then requires that the cavity sealing function be achieved with as low a purge air supply rate as possible. This, in turn, renders imperative an in-depth understanding of the pressure and velocity fields in the main gas path and within the disk cavities. In this work, experiments were carried out in a model 1.5-stage (stator-rotor-stator) axial air turbine to study the ingestion of main air into the aft, rotor-stator, disk cavity. The cavity featured rotor and stator rim seals with radial clearance and axial overlap and an inner labyrinth seal. First, time-average static pressure distribution was measured in the main gas path upstream and downstream of the rotor as well as in the cavity to ensure that a nominally steady run condition had been achieved. Main gas ingestion was determined by measuring the concentration distribution of tracer gas (CO2) in the cavity. To map the cavity fluid velocity field, particle image velocimetry was employed. Results are reported for two main air flow rates, two rotor speeds, and four purge air flow rates. / Dissertation/Thesis / M.S. Mechanical Engineering 2010
210

Solving the Complexity of the Manufacturing Equipment Disposition Process Using Engineering Tools and Techniques

January 2010 (has links)
abstract: The purpose of this thesis was to solve a complex problem in the manufacturing industry. The complex problem is the disposition and redeployment of specialized manufacturing equipment while accounting for import, export and supply chain security. The problem-solving approach is discussed in detail, focusing on lean and six sigma methodologies for a solution meeting both company internal and external requirements. This combination of lean and six sigma methodology has been validated by use in a pharmaceutical company. The process flow to dispose equipment properly is presented in detail. The process details can be used as best practices by any company dealing with specialized manufacturing equipment, enabling them to develop a robust process tailored to their organizational structure, hierarchy and resource availability. / Dissertation/Thesis / M.S.Tech Technology 2010

Page generated in 0.1015 seconds